🏷

Classifications

Harrison's Part

🔗

Mappings

MONDO

MONDO:0005661 babesiosis

Orphanet ORPHA:108 lists MONDO:0005661 as an exact cross-reference for Babesiosis.

📘

Definitions

2

Orphanet Babesiosis definition

Infectious disease caused by Babesia protozoa with manifestations ranging from asymptomatic infection to febrile hemolytic anemia and fulminant illness.

OTHER

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"Babesiosis is an infectious disease caused by protozoa of the genus Babesia and characterized by a febrile illness and hemolytic anemia"

Orphanet defines Babesiosis by Babesia infection, febrile illness, and hemolytic anemia.

Erythrocytic Babesia infection definition

Human babesiosis is caused by Babesia parasites that invade erythrocytes and produce a febrile hemolytic anemia, with severe persistent disease concentrated in asplenic or immunocompromised hosts.

OTHER

Show evidence (1 reference)

PMID:28202022 SUPPORT Human Clinical

"The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."

This review directly links Babesia infection, erythrocyte invasion, erythrocyte lysis, fever, and hemolytic anemia.

◈

Mechanistic Hypotheses

2

Canonical intraerythrocytic replication and hemolysis model

canonical_erythrocytic_disease CANONICAL

Evidence balance 1 support

Human disease is driven by Babesia invasion and replication within erythrocytes, followed by erythrocyte lysis, anemia, systemic illness, and parasite-burden-associated organ complications.

Pathograph links

Tick- or blood-mediated Babesia host entry -> Intraerythrocytic invasion and asexual replication DIRECT Host entry seeds parasites that establish the human erythrocytic phase.

Intraerythrocytic invasion and asexual replication -> Babesia-mediated erythrocyte lysis DIRECT Intracellular parasite replication culminates in destruction of infected erythrocytes.

Babesia-mediated erythrocyte lysis -> Systemic inflammation and cytopenias INDIRECT KNOWN INTERMEDIATES Erythrocyte destruction accompanies febrile systemic illness and hematologic abnormalities. Intermediates: Release of parasite and erythrocyte products; Innate immune and cytokine activation

Babesia-mediated erythrocyte lysis -> Hemolytic anemia DIRECT Destruction of infected red cells directly produces hemolytic anemia.

Babesia-mediated erythrocyte lysis -> Jaundice INDIRECT KNOWN INTERMEDIATES Hemolysis increases bilirubin production and contributes to jaundice. Intermediates: Heme catabolism and bilirubin generation

Systemic inflammation and cytopenias -> Parasitemia-associated multisystem dysfunction INDIRECT KNOWN INTERMEDIATES Systemic hematologic and inflammatory disturbance contributes to severe organ complications. Intermediates: Coagulopathy; Endothelial and tissue inflammatory injury

Show evidence (1 reference)

PMID:28202022 SUPPORT Human Clinical

"The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."

This human clinical review directly states the central erythrocyte-invasion and lysis mechanism.

Splenic and cell-mediated clearance modifies persistence and severity

host_clearance_severity_modifier CANONICAL

Evidence balance 2 support

Splenic filtration, macrophages, CD4 T cells, and interferon-gamma support parasite clearance; asplenia or immunosuppression shifts the balance toward persistent, relapsing, or life-threatening infection.

Pathograph links

Intraerythrocytic invasion and asexual replication -> Splenic macrophage and Th1-mediated parasite clearance INDIRECT KNOWN INTERMEDIATES Blood-stage infection elicits splenic and cell-mediated clearance responses. Intermediates: Recognition and removal of parasitized erythrocytes; CD4 T-cell and interferon-gamma activation

Intraerythrocytic invasion and asexual replication -> Impaired host clearance and persistent parasitemia INDIRECT KNOWN INTERMEDIATES In vulnerable hosts, blood-stage parasites persist when splenic or immune clearance is inadequate. Intermediates: Reduced splenic filtration; Impaired humoral or cell-mediated immunity

Splenic macrophage and Th1-mediated parasite clearance -> Splenomegaly INDIRECT KNOWN INTERMEDIATES Splenic immune and clearance activity is accompanied by organ enlargement. Intermediates: Splenic macrophage expansion; Erythrophagocytosis and hematopoietic support

Impaired host clearance and persistent parasitemia -> Parasitemia-associated multisystem dysfunction INDIRECT KNOWN INTERMEDIATES Persistent infection permits parasite burden and associated organ injury to accumulate. Intermediates: Sustained intraerythrocytic replication; Accumulating hemolytic and inflammatory injury

Impaired host clearance and persistent parasitemia -> Recurrent or relapsing infection DIRECT Incomplete parasite clearance permits persistence and clinical relapse.

Show evidence (2 references)

PMID:10417185 SUPPORT Model Organism

"These results suggest essential requirements for CD4(+) T cells and IFN-gamma in protective immunity against challenge infection with B. microti."

Controlled mouse experiments identify CD4 T cells and interferon-gamma as protective components.

PMID:28202022 SUPPORT Human Clinical

"follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."

Human evidence establishes the clinical severity boundary associated with impaired splenic or immune defense.

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Discussions and Knowledge Gaps

2

Which host, parasite, inflammatory, and organ-specific factors explain severe end-organ dysfunction when peripheral parasitemia is not high?

KNOWLEDGE GAP OPEN gap_babesiosis_severity_beyond_parasitemia

Attached to

pathophysiology#Parasitemia-associated multisystem dysfunction

Peak parasitemia correlates strongly with severity and informs exchange transfusion decisions, but some patients with organ dysfunction lack high-grade parasitemia. A parasite-percentage threshold therefore cannot fully represent tissue injury, host vulnerability, or timing.

Show evidence (1 reference)

PMID:33179803 SUPPORT Human Clinical

"Babesia microti parasitemia is closely associated with disease severity, though not all subjects with end-organ dysfunction had high-grade parasitemia."

The human cohort directly identifies the unresolved mismatch between circulating burden and organ injury.

Can tafenoquine be used safely and effectively as an adjunct to standard care for human babesiosis, and which regimen prevents relapse without unacceptable hemolytic risk?

KNOWLEDGE GAP OPEN gap_babesiosis_tafenoquine_translation

Attached to

clinical_trials#NCT06207370 pathophysiology#Impaired host clearance and persistent parasitemia

Tafenoquine plus atovaquone cures B. microti and B. duncani mouse models, and a small human relapsing-babesiosis series suggests adjunctive activity, but tafenoquine monotherapy failed in one case. A recruiting randomized Phase II add-on trial is testing hospitalized patients at low relapse risk; efficacy, optimal combinations, immunocompromised-host use, resistance, and G6PD-related safety remain unresolved.

Show evidence (3 references)

PMID:38169301 SUPPORT Model Organism

"We further show that a combination of tafenoquine and atovaquone achieves cure with no recrudescence in both models of human babesiosis."

Preclinical evidence supports the combination but does not establish human efficacy.

PMID:38814096 SUPPORT Human Clinical

"In 1 case, tafenoquine was administered alone and failed to prevent relapse."

The case series identifies a clinically important monotherapy limitation.

clinicaltrials:NCT06207370 SUPPORT Human Clinical

"This study is a double-blind, randomized, multisite, placebo-controlled trial comparing the safety and efficacy of TQ versus placebo in patients hospitalized for babesiosis"

The active trial directly addresses adjunctive human efficacy and safety.

⚙

Pathophysiology

7

Tick- or blood-mediated Babesia host entry

Tick inoculation most often initiates infection, while transfusion, congenital transmission, and organ transplantation can introduce parasites without the arthropod phase.

Canonical intraerythrocytic replication and hemolysis model

symbiont entry into host GO:0044409 ↑ INCREASED

Downstream

Intraerythrocytic invasion and asexual replication Host entry seeds parasites that establish the human erythrocytic phase.

Show evidence (2 references)

PMID:34539601 SUPPORT Human Clinical

"Most infections are transmitted by Ixodid (hard-bodied) ticks"

The review identifies the dominant initiating route.

PMID:34539601 SUPPORT Human Clinical

"although they occasionally can be spread through blood transfusion and rarely via perinatal transmission and organ transplantation."

The review establishes the alternate bloodstream-entry routes.

Intraerythrocytic invasion and asexual replication

Babesia invades human erythrocytes and replicates asexually, generating intraerythrocytic parasites and measurable parasitemia.

Canonical intraerythrocytic replication and hemolysis model Splenic and cell-mediated clearance modifies persistence and severity

erythrocyte CL:0000232

symbiont entry into host cell GO:0046718 ↑ INCREASED

Experimental models

Continuous Babesia duncani culture in human erythrocytes PRIMARY CELL CULTURE The primary-cell system directly propagates and measures the human erythrocytic parasite phase.

Downstream

Babesia-mediated erythrocyte lysis Intracellular parasite replication culminates in destruction of infected erythrocytes.

Splenic macrophage and Th1-mediated parasite clearance Blood-stage infection elicits splenic and cell-mediated clearance responses.

Impaired host clearance and persistent parasitemia In vulnerable hosts, blood-stage parasites persist when splenic or immune clearance is inadequate.

Show evidence (2 references)

PMID:28202022 SUPPORT Human Clinical

"Blood smear revealed intraerythrocytic Babesia, which was confirmed by PCR."

Direct microscopy with molecular confirmation demonstrates the intraerythrocytic state.

PMID:40908571 SUPPORT Other

"protozoan parasites whose life cycle includes sexual reproduction in the arthropod vector and asexual reproduction in the mainly mammalian host."

The current review assigns asexual replication to the mammalian phase.

Babesia-mediated erythrocyte lysis

Destruction of infected erythrocytes produces hemolysis, anemia, bilirubin generation, and downstream systemic manifestations. Babesiosis reaches the conserved premature-erythrocyte-destruction step by an infectious route: intraerythrocytic parasite replication lyses the host cell directly, and splenic macrophages additionally remove parasitized red cells. The destruction step, not the upstream cause, is what this entry shares with the hereditary and autoimmune hemolytic anemias.

Canonical intraerythrocytic replication and hemolysis model

erythrocyte CL:0000232

symbiont-mediated hemolysis of host erythrocyte GO:0019836 ↑ INCREASED

Downstream

Systemic inflammation and cytopenias Erythrocyte destruction accompanies febrile systemic illness and hematologic abnormalities.

Hemolytic anemia Destruction of infected red cells directly produces hemolytic anemia.

Jaundice Hemolysis increases bilirubin production and contributes to jaundice.

Show evidence (1 reference)

PMID:28202022 SUPPORT Human Clinical

"The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."

The review directly links parasite-mediated erythrocyte lysis with hemolytic anemia.

Splenic macrophage and Th1-mediated parasite clearance

The spleen filters parasitized erythrocytes, while macrophage and CD4 T-cell/IFN-gamma responses contribute to control. The detailed cellular mechanism is supported primarily by mouse models and is therefore not assumed to transfer quantitatively to humans.

Splenic and cell-mediated clearance modifies persistence and severity

macrophage CL:0000235 CD4-positive, alpha-beta T cell CL:0000624

Downstream

Splenomegaly Splenic immune and clearance activity is accompanied by organ enlargement.

Show evidence (2 references)

PMID:29445365 SUPPORT Model Organism

"We confirm that spleen is important for resolution of babesiosis in mammalian hosts."

The C3H/HeJ model supports splenic involvement in resolution.

PMID:10417185 SUPPORT Model Organism

"These results suggest essential requirements for CD4(+) T cells and IFN-gamma in protective immunity against challenge infection with B. microti."

Experimental depletion and knockout data support CD4 T-cell and interferon-gamma protection in mice.

Impaired host clearance and persistent parasitemia

Asplenia, advanced age, and immunosuppressive disease or therapy impair parasite clearance, enabling persistent or relapsing infection and raising the risk of high parasite burden. The specific risk set is informative about which defenses matter: asplenia removes the filtration site for parasitized erythrocytes, while B-cell lymphoma and rituximab — singled out by CDC — implicate humoral immunity alongside the CD4/IFN-gamma cellular arm demonstrated in mouse models. Congestive heart failure appears on the severe-disease risk list as a host vulnerability, not as a manifestation.

Splenic and cell-mediated clearance modifies persistence and severity

Downstream

Parasitemia-associated multisystem dysfunction Persistent infection permits parasite burden and associated organ injury to accumulate.

Recurrent or relapsing infection Incomplete parasite clearance permits persistence and clinical relapse.

Show evidence (4 references)

PMID:28202022 SUPPORT Human Clinical

"follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."

Human clinical evidence supports the link between vulnerable host states and impaired clearance.

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"Key risk factors for severe babesiosis and/or relapse include:"

CDC frames these host states as drivers of severe disease and relapse, which is the clinical signature of impaired parasite clearance.

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"Cancer (especially B-cell lymphoma or similar malignancy)"

CDC's specific call-out of B-cell lymphoma points to humoral immunity as a component of clearance, complementing the T-cell evidence.

+ 1 more reference

Systemic inflammation and cytopenias

Blood-stage infection and erythrocyte destruction are accompanied by cytokine activation and hematologic abnormalities, producing the febrile, flu-like syndrome and cytopenias. Cytokine-pathway detail is largely model-derived.

Canonical intraerythrocytic replication and hemolysis model

Downstream

Parasitemia-associated multisystem dysfunction Systemic hematologic and inflammatory disturbance contributes to severe organ complications.

Fever Infection-associated inflammatory signaling produces fever.

Headache The febrile systemic illness frequently includes headache.

Hyperhidrosis Febrile autonomic responses can produce sweating.

Thrombocytopenia Systemic hematologic disturbance commonly lowers platelet counts.

Leukopenia The systemic hematologic response can include reduced circulating leukocytes.

Hepatomegaly Reticuloendothelial and inflammatory activity can enlarge the liver.

Arthralgia The inflammatory flu-like syndrome commonly includes joint pain.

Myalgia The inflammatory flu-like syndrome commonly includes muscle pain.

Fatigue Anemia and systemic inflammation contribute to fatigue.

Cough Respiratory symptoms can include cough before or without severe pulmonary dysfunction.

Anorexia Systemic inflammatory signaling can suppress appetite.

Nausea and vomiting Systemic illness can include gastrointestinal symptoms.

Show evidence (2 references)

PMID:28202022 SUPPORT Human Clinical

"Full evaluation showed a febrile hemolytic anemia along with neutropenia and thrombocytopenia."

Human clinical evidence supports fever and cytopenias in the hemolytic illness.

PMID:29445365 SUPPORT Model Organism

"increase in pro-inflammatory plasmatic cytokines, IL-6, IFN-γ, and TNF-α together with the presence of activated macrophage in both blood and spleen could help in resolution of infection with B. microti."

Mouse data provide mechanistic support for inflammatory cytokine activation while also showing its potential protective role.

Parasitemia-associated multisystem dysfunction

Higher peak parasitemia is strongly associated with hemolysis, coagulopathy, longer hospitalization, and pulmonary, renal, and hepatic dysfunction, but parasite percentage is not the sole determinant of organ injury.

Downstream

Renal insufficiency Severe infection can produce acute renal dysfunction.

Disseminated intravascular coagulation Severe infection can trigger disseminated intravascular coagulation.

Respiratory insufficiency Severe infection can cause pulmonary dysfunction and respiratory insufficiency.

Hepatic failure Severe infection can progress from biochemical hepatic compromise to hepatic failure.

Myocardial infarction Severe hemolytic anemia and hemodynamic instability can precipitate myocardial infarction through demand ischemia rather than a Babesia-specific coronary lesion.

Coma Severe systemic disease can progress from confusion to coma.

Confusion Severe systemic disease can produce altered mental status and confusion.

Show evidence (2 references)

PMID:33179803 SUPPORT Human Clinical

"These results indicate a strong association between peak parasitemia level and disease severity."

The hospitalized cohort directly supports parasite burden as a severity correlate.

PMID:33179803 SUPPORT Human Clinical

"Babesia microti parasitemia is closely associated with disease severity, though not all subjects with end-organ dysfunction had high-grade parasitemia."

The same cohort establishes both the association and its clinically important limitation.

✶

Histopathology

1

Intraerythrocytic Babesia on peripheral blood smear

Giemsa-stained peripheral blood may show intraerythrocytic Babesia forms; careful manual review and species-aware confirmation are important because low parasitemia, Plasmodium, and staining artifacts can complicate interpretation.

Show evidence (2 references)

PMID:28202022 SUPPORT Human Clinical

"Blood smear revealed intraerythrocytic Babesia, which was confirmed by PCR."

Human clinical evidence directly documents the diagnostic microscopic finding.

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"When considering a babesiosis diagnosis, healthcare providers should explicitly request a manual (non-automated) review of the peripheral blood smear."

CDC specifically recommends manual smear review when babesiosis is suspected.

⬡

Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.

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Phenotypes

23

Blood 4

Hemolytic anemia VERY_FREQUENT HP:0001878

Show evidence (2 references)

ORPHA:108 SUPPORT Other

"HP:0001878 | Hemolytic anemia | Very frequent (99-80%)"

Orphanet lists hemolytic anemia as a very frequent Babesiosis phenotype.

PMID:28202022 SUPPORT Human Clinical

"The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."

Human clinical review evidence supports hemolytic anemia as a direct consequence of erythrocyte lysis.

Thrombocytopenia FREQUENT HP:0001873

Show evidence (2 references)

ORPHA:108 SUPPORT Other

"HP:0001873 | Thrombocytopenia | Frequent (79-30%)"

Orphanet lists thrombocytopenia as a frequent Babesiosis phenotype.

PMID:28202022 SUPPORT Human Clinical

"Full evaluation showed a febrile hemolytic anemia along with neutropenia and thrombocytopenia."

Human clinical review evidence supports thrombocytopenia with febrile hemolytic anemia.

Leukopenia FREQUENT Decreased total leukocyte count HP:0001882

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0001882 | Leukopenia | Frequent (79-30%)"

Orphanet lists leukopenia as a frequent Babesiosis phenotype.

Disseminated intravascular coagulation OCCASIONAL HP:0005521

Show evidence (2 references)

ORPHA:108 SUPPORT Other

"HP:0005521 | Disseminated intravascular coagulation | Occasional (29-5%)"

Orphanet lists disseminated intravascular coagulation as an occasional Babesiosis phenotype.

PMID:28202022 SUPPORT Human Clinical

"Hematologic manifestations of the disease are common. They can range from mild anemia, to severe pancytopenia, splenic rupture, disseminated intravascular coagulopathy (DIC), or even hemophagocytic lymphohistiocytosis (HLH)."

Human clinical review evidence supports DIC as part of the severe hematologic spectrum.

Cardiovascular 2

Splenomegaly FREQUENT HP:0001744

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0001744 | Splenomegaly | Frequent (79-30%)"

Orphanet lists splenomegaly as a frequent Babesiosis phenotype.

Myocardial infarction OCCASIONAL HP:0001658

Show evidence (2 references)

ORPHA:108 SUPPORT Other

"HP:0001658 | Myocardial infarction | Occasional (29-5%)"

Orphanet lists myocardial infarction as an occasional Babesiosis phenotype.

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"In severe cases, patients may exhibit thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, myocardial infarction, renal failure, hepatic compromise, altered mental status, and potentially, death."

CDC independently includes myocardial infarction in the severe complication spectrum.

Digestive 5

Jaundice FREQUENT HP:0000952

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0000952 | Jaundice | Frequent (79-30%)"

Orphanet lists jaundice as a frequent Babesiosis phenotype.

Hepatomegaly FREQUENT HP:0002240

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0002240 | Hepatomegaly | Frequent (79-30%)"

Orphanet lists hepatomegaly as a frequent Babesiosis phenotype.

Hepatic failure OCCASIONAL HP:0001399

Show evidence (2 references)

ORPHA:108 SUPPORT Other

"HP:0001399 | Hepatic failure | Occasional (29-5%)"

Orphanet lists hepatic failure as an occasional Babesiosis phenotype.

PMID:33179803 SUPPORT Human Clinical

"Laboratory measures indicating degrees of hemolysis, coagulopathy, and pulmonary, renal and hepatic dysfunction differed significantly across peak parasitemia levels."

Human clinical data link peak parasitemia with hepatic dysfunction.

Anorexia OCCASIONAL HP:0002039

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0002039 | Anorexia | Occasional (29-5%)"

Orphanet lists anorexia as an occasional Babesiosis phenotype.

Nausea and vomiting OCCASIONAL HP:0002017

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0002017 | Nausea and vomiting | Occasional (29-5%)"

Orphanet lists nausea and vomiting as an occasional Babesiosis phenotype.

Genitourinary 1

Renal insufficiency OCCASIONAL HP:0000083

Show evidence (2 references)

ORPHA:108 SUPPORT Other

"HP:0000083 | Renal insufficiency | Occasional (29-5%)"

Orphanet lists renal insufficiency as an occasional Babesiosis phenotype.

PMID:33179803 SUPPORT Human Clinical

"Laboratory measures indicating degrees of hemolysis, coagulopathy, and pulmonary, renal and hepatic dysfunction differed significantly across peak parasitemia levels."

Human clinical data link parasitemia with renal dysfunction.

Immune 1

Recurrent or relapsing infection FREQUENT Recurrent infections HP:0002719

Show evidence (2 references)

ORPHA:108 SUPPORT Other

"HP:0002719 | Recurrent infections | Frequent (79-30%)"

Orphanet lists recurrent infections as a frequent Babesiosis phenotype.

PMID:28202022 SUPPORT Human Clinical

"follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."

Human clinical review evidence supports relapsing or persistent babesiosis in high-risk hosts.

Integument 1

Hyperhidrosis FREQUENT HP:0000975

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0000975 | Hyperhidrosis | Frequent (79-30%)"

Orphanet lists hyperhidrosis as a frequent Babesiosis phenotype.

Metabolism 1

Fever VERY_FREQUENT HP:0001945

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0001945 | Fever | Very frequent (99-80%)"

Orphanet lists fever as a very frequent Babesiosis phenotype.

Nervous System 3

Headache VERY_FREQUENT HP:0002315

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0002315 | Headache | Very frequent (99-80%)"

Orphanet lists headache as a very frequent Babesiosis phenotype.

Confusion OCCASIONAL HP:0001289

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0001289 | Confusion | Occasional (29-5%)"

Orphanet lists confusion as an occasional Babesiosis phenotype.

Coma OCCASIONAL HP:0001259

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0001259 | Coma | Occasional (29-5%)"

Orphanet lists coma as an occasional Babesiosis phenotype.

Respiratory 2

Cough FREQUENT HP:0012735

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0012735 | Cough | Frequent (79-30%)"

Orphanet lists cough as a frequent Babesiosis phenotype.

Respiratory insufficiency OCCASIONAL HP:0002093

Show evidence (2 references)

ORPHA:108 SUPPORT Other

"HP:0002093 | Respiratory insufficiency | Occasional (29-5%)"

Orphanet lists respiratory insufficiency as an occasional Babesiosis phenotype.

PMID:33179803 SUPPORT Human Clinical

"Laboratory measures indicating degrees of hemolysis, coagulopathy, and pulmonary, renal and hepatic dysfunction differed significantly across peak parasitemia levels."

Human clinical data link peak parasitemia with pulmonary dysfunction.

Constitutional 3

Arthralgia FREQUENT HP:0002829

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0002829 | Arthralgia | Frequent (79-30%)"

Orphanet lists arthralgia as a frequent Babesiosis phenotype.

Myalgia FREQUENT HP:0003326

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0003326 | Myalgia | Frequent (79-30%)"

Orphanet lists myalgia as a frequent Babesiosis phenotype.

Fatigue FREQUENT HP:0012378

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"HP:0012378 | Fatigue | Frequent (79-30%)"

Orphanet lists fatigue as a frequent Babesiosis phenotype.

🗃️

External Assertions

1

Orphanet Babesiosis disease record

Orphanet structured disease record ORPHA:108

Orphanet's ORPHA:108 record provides the Babesiosis definition, all-ages onset, prevalence class, HPO phenotype table, and exact MONDO mapping used in this entry.

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"MONDO:0005661 | Exact"

Orphanet maps ORPHA:108 exactly to the MONDO term used by this entry.

💊

Medical Actions

5

Atovaquone plus azithromycin pharmacotherapy

Category: Therapeutic Action: Pharmacotherapy NCIT:C15986

Agent: atovaquone CHEBI:575568 azithromycin CHEBI:2955

Atovaquone plus azithromycin is the preferred combination for most symptomatic babesiosis. A randomized trial in non-life-threatening disease found efficacy comparable to clindamycin plus quinine with fewer adverse reactions.

Mechanism Target:

INHIBITS Intraerythrocytic invasion and asexual replication — Combination antimicrobial therapy suppresses the replicating blood-stage parasite burden.

Show evidence (1 reference)

PMID:11078770 SUPPORT Human Clinical

"For the treatment of babesiosis, a regimen of atovaquone and azithromycin is as effective as a regimen of clindamycin and quinine"

Randomized human treatment evidence supports activity against clinical Babesia infection.

Show evidence (2 references)

url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html SUPPORT Other

"atovaquone PLUS azithromycin (preferred)"

CDC identifies this as the preferred typical combination.

PMID:11078770 SUPPORT Human Clinical

"CONCLUSIONS: For the treatment of babesiosis, a regimen of atovaquone and azithromycin is as effective as a regimen of clindamycin and quinine and is associated with fewer adverse reactions."

The randomized trial supports efficacy and better tolerability in non-life-threatening disease.

Clindamycin plus quinine pharmacotherapy

Category: Therapeutic Action: Pharmacotherapy NCIT:C15986

Agent: clindamycin CHEBI:3745 quinine CHEBI:15854

Clindamycin plus quinine is an alternative combination, including when the preferred regimen cannot be used; the randomized comparison documented a substantially higher adverse-effect burden.

Mechanism Target:

INHIBITS Intraerythrocytic invasion and asexual replication — Combination antimicrobial therapy suppresses the replicating blood-stage parasite burden.

Show evidence (1 reference)

PMID:11078770 SUPPORT Human Clinical

"A course of clindamycin and quinine is the standard treatment"

The randomized clinical trial identifies this as an active comparator regimen.

Show evidence (2 references)

url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html SUPPORT Other

"clindamycin PLUS quinine* (alternative)"

CDC identifies this combination as the typical alternative.

PMID:11078770 SUPPORT Human Clinical

"Adverse effects were reported by 15 percent of the subjects who received atovaquone and azithromycin, as compared with 72 percent of those who received clindamycin and quinine (P<0.001)."

The trial quantifies the adverse-effect tradeoff.

Prolonged combination therapy for highly immunocompromised patients

Category: Therapeutic Action: Pharmacotherapy NCIT:C15986

Highly immunocompromised patients may need at least six consecutive weeks of combination therapy, close clinical and laboratory follow-up, and continuation until blood smears are negative for two consecutive weeks.

Mechanism Target:

INHIBITS Impaired host clearance and persistent parasitemia — Extended antimicrobial exposure compensates for impaired host clearance and suppresses persistent parasites.

Show evidence (1 reference)

url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html SUPPORT Other

"For highly immunocompromised patients, treatment may be required for at least 6 consecutive weeks or longer."

CDC directly links prolonged treatment duration to the high-risk host context.

Show evidence (1 reference)

url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html SUPPORT Other

"Treatment should be continued until parasites are no longer detected on smears for 2 consecutive weeks."

CDC provides the smear-guided stopping criterion for highly immunocompromised patients.

Red blood cell exchange transfusion for selected severe babesiosis

Category: Therapeutic Action: blood transfusion Ontology label: Blood Transfusion NCIT:C15192

Red blood cell exchange may be considered with high-grade parasitemia or substantial parasite burden accompanied by severe hemolytic anemia or pulmonary, renal, or hepatic decline. Parasitemia must be interpreted with clinical status.

Mechanism Target:

INHIBITS Intraerythrocytic invasion and asexual replication — Exchange physically removes parasite-infected erythrocytes and lowers circulating blood-stage burden.

Show evidence (1 reference)

PMID:33179803 SUPPORT Human Clinical

"Nineteen subjects underwent RCE, all with peak parasitemia ≥9% and some degree of end-organ dysfunction."

The clinical series documents exchange use in high-burden infection.

INHIBITS Parasitemia-associated multisystem dysfunction — Rapid burden reduction is intended to mitigate ongoing severe hemolytic and organ injury.

Show evidence (1 reference)

PMID:33179803 SUPPORT Human Clinical

"Our data suggest that the use of parasitemia >10%, coupled with clinical status, is a reasonable indicator for RCE in babesiosis patients."

Human cohort evidence supports integrating parasite burden with organ-level clinical status.

Show evidence (2 references)

url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html SUPPORT Other

"Exchange transfusions in which portions of a patient's blood or blood cells are replaced with transfused blood components"

CDC includes exchange transfusion among supportive interventions for selected severe illness.

PMID:33179803 SUPPORT Human Clinical

"Babesia microti parasitemia is closely associated with disease severity, though not all subjects with end-organ dysfunction had high-grade parasitemia."

The cohort cautions against using a numeric parasite threshold without clinical assessment.

Tick-bite avoidance counseling

Category: Counseling / Informational Action: tick-bite avoidance counseling Ontology label: Behavioral Counseling NCIT:C181743

No babesiosis vaccine exists, so primary prevention rests entirely on interrupting the tick-exposure step: avoiding tick habitat, using repellents, wearing covering clothing, and performing tick self-checks. Successful avoidance acts upstream of the host-entry trigger by preventing the inoculation event itself, though it is the patient's resulting behavior rather than the advice that interrupts transmission. Tick avoidance does not address the transfusion, transplant, or congenital routes, which is why donor screening matters independently.

Show evidence (1 reference)

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"There is no vaccine for babesiosis. Encourage patients to avoid ticks, use tick repellents, wear socks, long-sleeved shirts, and pants, and perform self-checks for the presence of ticks."

CDC directly states the absence of a vaccine and the recommended personal protective measures.

🌍

Environmental Factors

2

Exposure to infected black-legged ticks

Residence in or travel to endemic northeastern and upper midwestern areas with infected Ixodes scapularis creates the principal environmental acquisition risk for U.S. babesiosis.

Show evidence (1 reference)

DOI:10.15585/mmwr.mm7211a1 SUPPORT Human Clinical

"In the United States, most babesiosis cases are caused by Babesia microti"

CDC surveillance identifies B. microti as the dominant U.S. agent; the same sentence continues to name black-legged tick bites in northeastern and midwestern states as the transmission route. The quote is trimmed to the portion that is contiguous in the cached PDF text, which hyphenates "black-legged" across a line break.

Mechanism Target:

TRIGGERS Tick- or blood-mediated Babesia host entry — The bite of an infected Ixodes tick inoculates sporozoites directly, which is the arthropod arm of this entry node and the route that accounts for most infections.

Show evidence (1 reference)

PMID:34539601 SUPPORT Human Clinical

"Most infections are transmitted by Ixodid (hard-bodied) ticks"

States that most infections are transmitted by ixodid ticks, establishing the tick bite as the dominant route of parasite entry.

Exposure to unscreened or infected donated blood

Transfusion can bypass the tick vector and introduce intraerythrocytic parasites directly into a recipient, including recipients vulnerable to severe infection.

Show evidence (1 reference)

PMID:34539601 SUPPORT Human Clinical

"they occasionally can be spread through blood transfusion"

The review establishes infected blood products as an acquisition exposure.

Mechanism Target:

TRIGGERS Tick- or blood-mediated Babesia host entry — Transfusion bypasses the arthropod phase entirely, delivering already-intraerythrocytic parasites straight into the recipient's circulation. It is the blood-mediated arm of the same entry node.

Show evidence (1 reference)

PMID:34539601 SUPPORT Human Clinical

"they occasionally can be spread through blood transfusion"

Confirms blood transfusion as a route by which the parasite is spread, independent of any tick exposure.

🔬

Biochemical Markers

3

Peripheral blood parasitemia (INCREASED)

Context: The fraction of infected erythrocytes is a dynamic measure of parasite burden. Higher peak parasitemia correlates with severity, but clinical status and organ dysfunction must be assessed independently.

Pathograph Readouts

Readout Of Intraerythrocytic invasion and asexual replication Positive Diagnostic

The infected-erythrocyte fraction reports the burden of the intraerythrocytic parasite phase.

Show evidence (1 reference)

PMID:33179803 SUPPORT Human Clinical

"Subjects were stratified according to peak parasitemia: <1% (n = 34), 1-5% (n = 24), 5-10% (n = 15), and >10% (n = 18)."

The clinical cohort quantifies blood-stage burden as the percentage parasitemia.

Correlates With Parasitemia-associated multisystem dysfunction Positive Prognostic

Increasing peak parasitemia generally tracks with increasing disease severity, but is not sufficient alone for risk classification.

Show evidence (1 reference)

PMID:33179803 SUPPORT Human Clinical

"Babesia microti parasitemia is closely associated with disease severity, though not all subjects with end-organ dysfunction had high-grade parasitemia."

The cohort supports a positive but imperfect severity relationship.

Show evidence (1 reference)

PMID:33179803 SUPPORT Human Clinical

"These results indicate a strong association between peak parasitemia level and disease severity."

Human inpatient data establish parasitemia as a severity-associated blood marker.

Hemolytic laboratory pattern (INCREASED)

Context: Anemia with laboratory evidence of erythrocyte destruction is a core disease readout; thrombocytopenia and elevations in liver enzymes, blood urea nitrogen, or creatinine can accompany more complicated illness.

Pathograph Readouts

Readout Of Babesia-mediated erythrocyte lysis Positive Diagnostic

Laboratory evidence of red-cell destruction reports the hemolytic mechanism.

Show evidence (1 reference)

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"For acutely ill patients, the findings on routine laboratory testing frequently include hemolytic anemia and thrombocytopenia."

CDC identifies hemolytic anemia as a frequent laboratory finding in acute illness.

Show evidence (1 reference)

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"For acutely ill patients, the findings on routine laboratory testing frequently include hemolytic anemia and thrombocytopenia."

CDC directly supports the characteristic acute laboratory pattern.

Babesia DNA detected by nucleic acid amplification (POSITIVE)

Context: Babesia PCR supports direct detection, including when organism burden is below the reliable threshold of routine microscopy or when treatment response and persistence require molecular assessment.

Pathograph Readouts

Readout Of Intraerythrocytic invasion and asexual replication Present Absent Diagnostic

Babesia DNA in blood directly reports current or recently active blood-stage infection in the appropriate clinical context.

Show evidence (1 reference)

PMID:28202022 SUPPORT Human Clinical

"Blood smear revealed intraerythrocytic Babesia, which was confirmed by PCR."

Human clinical evidence uses PCR to confirm the smear-defined blood-stage infection.

Readout Of Impaired host clearance and persistent parasitemia Present Absent Monitoring

Persistent Babesia DNA can reveal residual infection when smear parasitemia is difficult to detect.

Show evidence (1 reference)

PMID:29445365 SUPPORT Model Organism

"Although parasitemia was undetectable by microscopy at 21 days of infection, detection of B. microti DNA by our qPCR supports possibility of continuing low-level infection."

Mouse-model evidence demonstrates molecular detection of low-level persistence after smear negativity; human monitoring implications remain inferential.

Show evidence (1 reference)

PMID:34539601 SUPPORT Human Clinical

"Diagnosis is usually confirmed by blood smear or polymerase chain reaction (PCR)."

The review identifies PCR as a standard confirmatory method.

🔬

Diagnosis

3

Manual peripheral blood-smear examination

Request manual light-microscopic review of peripheral blood smears for intraerythrocytic Babesia. Multiple smears may be required at low burden, and expert review may be needed to distinguish Babesia from Plasmodium or artifacts.

blood smear test NCIT:C25294

Results: Intraerythrocytic Babesia forms support active infection; species confirmation may require molecular testing.

Show evidence (2 references)

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"When considering a babesiosis diagnosis, healthcare providers should explicitly request a manual (non-automated) review of the peripheral blood smear."

CDC specifically recommends manual rather than automated smear review.

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"parasites through light-microscopic examination of blood smears, though sometimes multiple smears may need to be examined."

CDC supports microscopy and repeat-smear review when necessary.

Babesia nucleic acid amplification testing

PCR or another validated nucleic acid amplification test confirms Babesia DNA in blood and is particularly useful when smear burden is low or species resolution is needed.

nucleic acid amplification testing NCIT:C20055

Results: A positive species-appropriate Babesia nucleic acid test supports active or recently active infection in clinical context.

Show evidence (2 references)

PMID:34539601 SUPPORT Human Clinical

"Diagnosis is usually confirmed by blood smear or polymerase chain reaction (PCR)."

The review identifies PCR as a usual confirmatory modality.

PMID:28202022 SUPPORT Human Clinical

"Blood smear revealed intraerythrocytic Babesia, which was confirmed by PCR."

A human clinical example demonstrates molecular confirmation of smear findings.

Babesia serology as supportive testing

Species-appropriate serology can support exposure assessment or diagnosis, but it should be interpreted with direct-detection tests because antibodies may persist and immunocompromised patients may mount weak responses.

serology testing NCIT:C25294

Results: Positive Babesia-specific antibodies support exposure; direct detection is preferred for acute active infection.

Show evidence (1 reference)

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"by blood-smear examination and, if indicated, by other means, such as molecular and/or serologic methods tailored to the setting/species."

CDC supports serology as a context- and species-tailored adjunct to direct examination.

📈

Progression

4

Asymptomatic or subclinical infection

Duration: Variable; infection may be detected incidentally or through donor screening.

Many infections remain asymptomatic, particularly in immunocompetent hosts.

Show evidence (1 reference)

PMID:28202022 SUPPORT Human Clinical

"The infection is usually asymptomatic or self-limited in the immunocompetent host"

Human clinical review evidence supports an asymptomatic or self-limited initial course.

Acute symptomatic babesiosis

Duration: Acute febrile illness; standard treatment is generally 7–10 days in immunocompetent patients.

Fever, fatigue, headache, myalgia, hemolytic anemia, and thrombocytopenia are typical.

Show evidence (1 reference)

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"infection ranges from subclinical to severe, presenting with flu-like symptoms and clinical or laboratory signs of red blood cell destruction."

CDC describes the transition from subclinical infection to symptomatic hemolytic illness.

Severe high-burden or complicated babesiosis

Duration: Acute hospitalization; duration depends on parasite clearance and organ recovery.

Complications include DIC, respiratory distress, renal or hepatic dysfunction, altered mental status, and death.

Show evidence (1 reference)

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"In severe cases, patients may exhibit thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, myocardial infarction, renal failure, hepatic compromise, altered mental status, and potentially, death."

CDC defines the organ-complication spectrum of severe disease.

Persistent or relapsing infection

Duration: Weeks to months or longer in highly immunocompromised patients.

Impaired splenic or immune clearance can require prolonged therapy and close smear monitoring.

Show evidence (1 reference)

PMID:28202022 SUPPORT Human Clinical

"follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."

The review links impaired host defense with persistence, relapse, and life-threatening progression.

📊

Prevalence

2

Europe

Point Prevalence ≤0.1 per 100,000 <1 in 1,000,000

Orphanet records a European point-prevalence class below 1 per 1,000,000. European babesiosis is caused predominantly by Babesia divergens and B. venatorum and is far rarer than U.S. Babesia microti infection, so this class should not be generalized to the endemic northeastern United States.

Show evidence (1 reference)

ORPHA:108 SUPPORT Other

"<1 / 1 000 000 | Europe | Point prevalence | OTHER"

Orphanet provides the European point-prevalence class for babesiosis.

Rhode Island, United States (2015)

Annual Incidence 18.0 per 100,000 1–9 per 10,000

Highest single state-year reported incidence observed in CDC national surveillance during 2011-2019; Maine (10.3 per 100,000 in 2019) and Massachusetts (9.1 in 2019) were next highest. These are reported-case incidences, not seroprevalence or true infection rates: asymptomatic infections, unreported cases, and the 10 states where babesiosis is not a reportable condition by law are not captured, so the values are lower bounds.

Show evidence (1 reference)

DOI:10.15585/mmwr.mm7211a1 SUPPORT Human Clinical

"reported incidences were Rhode Island (18.0 per 100,000 population in 2015), Maine (10.3 in 2019), and Massachusetts (9.1 in 2019)."

CDC surveillance reports the highest state-level annual babesiosis incidences during the 2011-2019 analysis period.

🌍

Epidemiology

2

United States reported burden, 2011–2019

CDC received 16,456 reported babesiosis cases from 37 states during 2011–2019; 98.2% came from the 10 states included in the longitudinal incidence analysis.

Surveillance case definitions and state reporting requirements Concentration of transmission in northeastern and upper midwestern states

Show evidence (1 reference)

DOI:10.15585/mmwr.mm7211a1 SUPPORT Human Clinical

"During 2011–2019, a total of 16,456 cases of babesiosis were reported to CDC by 37 states, including 16,174 (98.2%) reported from the 10 states included in this analysis"

CDC surveillance provides the reported national case count and analytic-state concentration.

Expanding northeastern endemicity

Incidence increased significantly in eight northeastern states during 2011–2019, with Maine, New Hampshire, and Vermont newly recognized as having endemic transmission comparable to other high-incidence states.

Geographic expansion of Ixodes scapularis Increasing infection incidence in northeastern states

Show evidence (2 references)

DOI:10.15585/mmwr.mm7211a1 SUPPORT Human Clinical

"Incidence increased significantly in Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, and Vermont"

The multistate surveillance analysis documents statistically significant incidence increases.

DOI:10.15585/mmwr.mm7211a1 SUPPORT Human Clinical

"These three states should now be considered to have endemic transmission comparable to that in other high-incidence states"

CDC identifies Maine, New Hampshire, and Vermont as newly endemic in this surveillance period.

🦠

Infectious Agent

5

Babesia

Protozoan genus responsible for human babesiosis.

Babesia NCBITaxon:5864

Show evidence (2 references)

ORPHA:108 SUPPORT Other

"Babesiosis is an infectious disease caused by protozoa of the genus Babesia"

Orphanet identifies Babesia protozoa as the causative genus.

PMID:28202022 SUPPORT Human Clinical

"The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."

This review confirms the causative genus and erythrocyte tropism.

Babesia microti

Most common Babesia species causing human babesiosis.

Babesia microti NCBITaxon:5868

Show evidence (1 reference)

PMID:34539601 SUPPORT Human Clinical

"Babesia microti, the most common species that infects humans, is endemic in the Northeastern and upper Midwestern United States and is sporadically reported elsewhere in the world."

The Asta-retrieved review identifies B. microti as the most common human-infecting Babesia species.

Babesia divergens

Human-infecting Babesia species that is an important cause of European babesiosis.

Babesia divergens NCBITaxon:32595

Show evidence (1 reference)

PMID:40908571 SUPPORT Other

"B. divergens, B. duncani, B. microti, B. venatorum"

The current review includes B. divergens among Babesia species known to infect humans.

Babesia duncani

Human-infecting Babesia species with established human-erythrocyte culture and mouse model systems.

Babesia duncani NCBITaxon:323732

Show evidence (1 reference)

PMID:35512141 SUPPORT In Vitro

"the ability to propagate Babesia duncani both in vitro in human erythrocytes and in mice makes it a unique pathogen to study Babesia biology and pathogenesis."

The study directly identifies B. duncani as a human-disease-relevant Babesia species used in erythrocyte and mouse systems.

Babesia venatorum

Human-infecting Babesia species reported particularly in Europe.

Babesia venatorum NCBITaxon:171411

Show evidence (1 reference)

PMID:40908571 SUPPORT Other

"B. divergens, B. duncani, B. microti, B. venatorum"

The current review includes B. venatorum among Babesia species known to infect humans.

↔️

Transmission

3

Ixodid tick transmission

Most human infections are acquired from hard-bodied Ixodes tick vectors, with regional endemicity in the northeastern and upper midwestern United States.

Show evidence (2 references)

PMID:34539601 SUPPORT Human Clinical

"Most infections are transmitted by Ixodid (hard-bodied) ticks"

The review identifies Ixodid tick bites as the main transmission route.

PMID:28202022 SUPPORT Human Clinical

"Babesiosis, a zoonotic parasitic infection transmitted by the Ixodes tick, has become an emerging health problem in humans that is attracting attention worldwide."

This review also supports Ixodes tick-mediated zoonotic transmission.

Transfusion-associated transmission

Viable Babesia in donated blood can transmit infection to transfusion recipients.

Show evidence (1 reference)

PMID:34539601 SUPPORT Human Clinical

"they occasionally can be spread through blood transfusion"

The review identifies blood transfusion as an established non-vector route.

Congenital and organ-transplant transmission

Rare non-vector routes include perinatal transmission and transplantation of organs from infected donors.

Show evidence (1 reference)

PMID:34539601 SUPPORT Human Clinical

"although they occasionally can be spread through blood transfusion and rarely via perinatal transmission and organ transplantation."

The review identifies perinatal and organ-transplant transmission as rare routes.

⚖️

Clinical Burden

Variable

Many infections are asymptomatic or self-limited, but asplenic, immunocompromised, and older patients can develop persistent parasitemia, severe hemolysis, multiorgan failure, prolonged treatment needs, and death.

Show evidence (1 reference)

PMID:28202022 SUPPORT Human Clinical

"The infection is usually asymptomatic or self-limited in the immunocompetent host, or follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."

The review directly supports the strongly variable burden assignment.

🔀

Differential Diagnoses

2

Conditions with similar clinical presentations that must be differentiated from Babesiosis:

Malaria MONDO:0005136

Overlapping Features Malaria can cause a febrile intraerythrocytic parasitemia with anemia and may resemble babesiosis on thin blood smear, particularly when ring forms are sparse.

Distinguishing Features

Travel or residence in a malaria-endemic area shifts the pretest probability.
Expert morphology, species-specific PCR, and appropriate rapid antigen tests distinguish Plasmodium from Babesia.
Babesia can show tetrads, while Plasmodium has species-specific pigment and developmental forms.

Show evidence (1 reference)

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html SUPPORT Other

"Distinguishing Babesia and Plasmodium parasites (especially P. falciparum) and artifacts like stain or platelet debris can be challenging."

CDC explicitly identifies Plasmodium as a microscopic diagnostic challenge.

Human granulocytic anaplasmosis

Overlapping Features Anaplasmosis shares Ixodes scapularis exposure, fever, headache, myalgia, leukopenia, and thrombocytopenia with babesiosis, and coinfection can occur.

Distinguishing Features

Hemolytic anemia and intraerythrocytic parasites favor babesiosis.
Species-specific blood PCR distinguishes Babesia from Anaplasma phagocytophilum.
Detection of granulocytic morulae supports anaplasmosis rather than babesiosis.

Show evidence (2 references)

PMID:40908571 SUPPORT Other

"B. microti, Borrelia burgdorferi and Anaplasma phagocytophilum are all transmitted by black-legged ticks ( Ixodes scapularis) and therefore co-infection is likely and has been reported."

The review establishes shared vector exposure and the possibility of coinfection.

DOI:10.15585/mmwr.mm7211a1 SUPPORT Human Clinical

"other tickborne conditions can have similar clinical manifestations, risk for disease acquisition, and geographic distribution"

CDC surveillance guidance supports considering clinically overlapping tick-borne conditions.

📊

Related Datasets

1

Whole-genome capture sequences from 25 Babesia microti isolates sra:SRP058536

Multiplex hybrid-capture sequence data from 25 B. microti isolates obtained from Ixodes scapularis and human blood across U.S. sampling sites, used to characterize genome-wide diversity and northeastern population structure.

Babesia microti WGS n=25 Multiplexed hybrid capture and...

Ixodes scapularis-derived Babesia microti isolate NCBITaxon:6945 human-blood-derived Babesia microti isolate UBERON:0000178

Conditions: Tick-derived Babesia microti Human-infecting Babesia microti

PMID:27821055

Show evidence (2 references)

PMID:27821055 SUPPORT Other

"we used multiplexed hybrid capture of 25 B. microti isolates obtained from I. scapularis and human blood."

The publication directly states the dataset design, isolate count, and sources.

PMID:27821055 SUPPORT Other

"Metadata and sequence data of each sample in this study were submitted to NCBI Short Read Archive"

The data-availability statement supports public SRA deposition.

🔬

Clinical Trials

3

NCT06207370 PHASE_II RECRUITING

Double-blind, randomized, multisite, placebo-controlled Phase II trial of oral tafenoquine versus placebo added to atovaquone/azithromycin standard care in 33 estimated hospitalized participants at low risk for relapse. Registry status was checked 2026-07-23; estimated completion is July 2027.

Show evidence (1 reference)

clinicaltrials:NCT06207370 SUPPORT Human Clinical

"This study is a double-blind, randomized, multisite, placebo-controlled trial comparing the safety and efficacy of TQ versus placebo in patients hospitalized for babesiosis with low risk for relapsing disease"

The registry summary directly supports the interventional design and enrolled disease context.

NCT07345988 NOT_APPLICABLE RECRUITING

Retrospective multicenter observational study describing epidemiologic, clinical, biological, treatment, and prognostic characteristics of an estimated 100 human babesiosis cases in metropolitan France. Registry status was checked 2026-07-23; estimated completion is May 2027.

Show evidence (1 reference)

clinicaltrials:NCT07345988 SUPPORT Human Clinical

"The aim of this study is to describe the epidemiological, clinical, biological, therapeutic, and prognostic characteristics of human babesiosis cases diagnosed in metropolitan France."

The registry summary directly states the observational study objective.

NCT01528449 PHASE_III COMPLETED

Completed prospective and retrospective study of 90,116 blood donors using real-time PCR and indirect fluorescent antibody assays for B. microti screening.

Show evidence (1 reference)

clinicaltrials:NCT01528449 SUPPORT Human Clinical

"Both prospective and retrospective (look back) study of blood donors for laboratory evidence of babesia microti infection."

The registry summary establishes the donor-screening study population and design.

🧫

Experimental Models

1

Continuous Babesia duncani culture in human erythrocytes PRIMARY_CELL_CULTURE

A continuous human-erythrocyte culture system supports B. duncani development and drug-susceptibility testing and connects to a controlled mouse infection model.

Organism

human NCBITaxon:9606

Cell source

Human erythrocytes

Culture

Continuous in-vitro propagation of Babesia duncani in human erythrocytes

Publication

PMID:35512141

Pathograph links

Intraerythrocytic invasion and asexual replication The primary-cell system directly propagates and measures the human erythrocytic parasite phase.

Show evidence (1 reference)

PMID:35512141 SUPPORT In Vitro

"the ability to propagate Babesia duncani both in vitro in human erythrocytes and in mice makes it a unique pathogen to study Babesia biology and pathogenesis."

The source explicitly supports propagation of the intraerythrocytic phase in human cells.

Show evidence (1 reference)

PMID:35512141 SUPPORT In Vitro

"Here we report an optimized B. duncani in culture-in mouse (ICIM) model that combines continuous in vitro culture of the parasite with a precise model of lethal infection in mice."

The source directly describes the continuous culture component and its model linkage.

🐁

Animal Models

3

Mus musculus Experimental infection

Susceptible C3H/HeJ mice infected with B. microti develop high parasitemia, a sharp hemoglobin decrease, splenic enlargement and architectural change, macrophage expansion, and Th1-associated clearance.

Species

Mus musculus

Background

C3H/HeJ

Show evidence (2 references)

PMID:29445365 SUPPORT Model Organism

"Susceptible C3H/HeJ mice show several human-like disease manifestations and are ideal to study pathogenesis of Babesia species."

The authors explicitly frame this strain as a pathogenesis model with human-like manifestations.

PMID:29445365 SUPPORT Model Organism

"Peak parasitemia of 42.5% was immediately followed by diminished hemoglobin level."

The model reproduces parasite-burden-associated anemia.

Mus musculus Protective-immunity challenge model

Recovered BALB/c mice resist B. microti rechallenge; CD4 depletion, interferon-gamma neutralization, and interferon-gamma deficiency test the cellular requirements for protection.

Species

Mus musculus

Background

BALB/c

Show evidence (2 references)

PMID:10417185 SUPPORT Model Organism

"BALB/c mice which recovered from primary infection showed strong protective immunity against challenge infection."

Rechallenge directly demonstrates acquired protection in this mouse background.

PMID:10417185 SUPPORT Model Organism

"These results suggest essential requirements for CD4(+) T cells and IFN-gamma in protective immunity against challenge infection with B. microti."

Perturbation experiments identify required protective immune components.

Mus musculus Babesia duncani in-culture-in-mouse lethal infection model

The B. duncani ICIM system couples continuous growth in human erythrocytes to reproducible lethal infection in mice for virulence and drug-response studies.

Species

Mus musculus

Background

C3H/HeJ

Show evidence (1 reference)

PMID:35512141 SUPPORT Model Organism

"Here we report an optimized B. duncani in culture-in mouse (ICIM) model that combines continuous in vitro culture of the parasite with a precise model of lethal infection in mice."

The study directly defines the linked in-vitro/in-vivo model.

{ }

Source YAML

click to show

name: Babesiosis
creation_date: "2026-05-10T14:07:24Z"
category: Infectious Disease
parents:
- Protozoa infectious disease
- Tick-borne disease
synonyms:
- Babesia infection
- Human babesiosis
- Piroplasmosis
description: >-
  Babesiosis is an intraerythrocytic protozoal infection caused by Babesia
  species. Most U.S. cases are caused by Babesia microti and acquired through
  Ixodes scapularis tick bites, although transfusion, organ-transplant, and
  congenital transmission also occur. Infection ranges from asymptomatic
  parasitemia to febrile hemolytic anemia and life-threatening pulmonary,
  renal, hepatic, coagulation, cardiovascular, or neurologic complications.
  Older, asplenic, and immunocompromised people are at greatest risk of severe,
  persistent, or relapsing disease.
disease_term:
  preferred_term: babesiosis
  term:
    id: MONDO:0005661
    label: babesiosis
mappings:
  mondo_mappings:
  - term:
      id: MONDO:0005661
      label: babesiosis
    mapping_predicate: skos:exactMatch
    mapping_source: Orphanet ORPHA:108
    mapping_justification: >-
      Orphanet ORPHA:108 lists MONDO:0005661 as an exact cross-reference for
      Babesiosis.
external_assertions:
- name: Orphanet Babesiosis disease record
  source: Orphanet
  assertion_type: structured_disease_record
  external_id: ORPHA:108
  url: http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=108
  description: >-
    Orphanet's ORPHA:108 record provides the Babesiosis definition, all-ages
    onset, prevalence class, HPO phenotype table, and exact MONDO mapping used
    in this entry.
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "MONDO:0005661 | Exact"
    explanation: Orphanet maps ORPHA:108 exactly to the MONDO term used by this entry.
definitions:
- name: Orphanet Babesiosis definition
  definition_type: OTHER
  description: >-
    Infectious disease caused by Babesia protozoa with manifestations ranging
    from asymptomatic infection to febrile hemolytic anemia and fulminant
    illness.
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Babesiosis is an infectious disease caused by protozoa of the genus <i>Babesia</i> and characterized by a febrile illness and hemolytic anemia"
    explanation: Orphanet defines Babesiosis by Babesia infection, febrile illness, and hemolytic anemia.
- name: Erythrocytic Babesia infection definition
  definition_type: OTHER
  description: >-
    Human babesiosis is caused by Babesia parasites that invade erythrocytes and
    produce a febrile hemolytic anemia, with severe persistent disease
    concentrated in asplenic or immunocompromised hosts.
  evidence:
  - reference: PMID:28202022
    reference_title: "Hematologic manifestations of babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."
    explanation: This review directly links Babesia infection, erythrocyte invasion, erythrocyte lysis, fever, and hemolytic anemia.
references:
- reference: ORPHA:108
  title: Babesiosis
  findings: []
- reference: PMID:34539601
  title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
  found_in:
  - Babesiosis-deep-research-asta.md
  findings: []
- reference: PMID:28202022
  title: Hematologic manifestations of babesiosis.
  findings: []
- reference: PMID:11078770
  title: Atovaquone and azithromycin for the treatment of babesiosis.
  findings: []
- reference: PMID:33179803
  title: Parasite burden and red blood cell exchange transfusion for babesiosis.
  findings: []
- reference: PMID:40908571
  title: "Human babesiosis: The past, present and future."
  findings: []
- reference: DOI:10.15585/mmwr.mm7211a1
  title: "Trends in Reported Babesiosis Cases — United States, 2011–2019"
  findings: []
- reference: PMID:27821055
  title: Babesia microti from humans and ticks hold a genomic signature of strong population structure in the United States.
  findings: []
- reference: PMID:29445365
  title: Babesia microti Infection Changes Host Spleen Architecture and Is Cleared by a Th1 Immune Response.
  findings: []
- reference: PMID:10417185
  title: Roles of CD4(+) T cells and gamma interferon in protective immunity against Babesia microti infection in mice.
  findings: []
- reference: PMID:35512141
  title: "Babesia duncani as a Model Organism to Study the Development, Virulence, and Drug Susceptibility of Intraerythrocytic Parasites In Vitro and In Vivo."
  findings: []
- reference: PMID:38169301
  title: Tafenoquine-Atovaquone Combination Achieves Radical Cure and Confers Sterile Immunity in Experimental Models of Human Babesiosis.
  findings: []
- reference: PMID:38814096
  title: "Tafenoquine for Relapsing Babesiosis: A Case Series."
  findings: []
- reference: clinicaltrials:NCT06207370
  title: A Double-blind Placebo-controlled Study to Assess the Safety and Efficacy of Oral Tafenoquine Plus Standard of Care Versus Placebo Plus Standard of Care in Patients Hospitalized for Babesiosis
  findings: []
- reference: clinicaltrials:NCT07345988
  title: "Human Babesiosis in Metropolitan France: a Retrospective and Multicenter Descriptive Analysis."
  findings: []
- reference: clinicaltrials:NCT01528449
  title: Blood Donation Screening for Babesia Microti by Real-time Polymerase Chain Reaction (PCR) and by Indirect Flourescent Antibody (IFA) Assays  # codespell:ignore-line
  findings: []
- reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
  title: Clinical Overview of Babesiosis | Babesiosis | CDC
  findings: []
- reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html
  title: Clinical Care of Babesiosis | Babesiosis | CDC
  findings: []
infectious_agent:
- name: Babesia
  description: Protozoan genus responsible for human babesiosis.
  infectious_agent_term:
    preferred_term: Babesia
    term:
      id: NCBITaxon:5864
      label: Babesia
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Babesiosis is an infectious disease caused by protozoa of the genus <i>Babesia</i>"
    explanation: Orphanet identifies Babesia protozoa as the causative genus.
  - reference: PMID:28202022
    reference_title: "Hematologic manifestations of babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."
    explanation: This review confirms the causative genus and erythrocyte tropism.
- name: Babesia microti
  description: Most common Babesia species causing human babesiosis.
  infectious_agent_term:
    preferred_term: Babesia microti
    term:
      id: NCBITaxon:5868
      label: Babesia microti
  evidence:
  - reference: PMID:34539601
    reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Babesia microti, the most common species that infects humans, is endemic in the Northeastern and upper Midwestern United States and is sporadically reported elsewhere in the world."
    explanation: The Asta-retrieved review identifies B. microti as the most common human-infecting Babesia species.
- name: Babesia divergens
  description: Human-infecting Babesia species that is an important cause of European babesiosis.
  infectious_agent_term:
    preferred_term: Babesia divergens
    term:
      id: NCBITaxon:32595
      label: Babesia divergens
  evidence:
  - reference: PMID:40908571
    reference_title: "Human babesiosis: The past, present and future."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "B. divergens, B. duncani, B. microti, B. venatorum"
    explanation: The current review includes B. divergens among Babesia species known to infect humans.
- name: Babesia duncani
  description: Human-infecting Babesia species with established human-erythrocyte culture and mouse model systems.
  infectious_agent_term:
    preferred_term: Babesia duncani
    term:
      id: NCBITaxon:323732
      label: Babesia duncani
  evidence:
  - reference: PMID:35512141
    reference_title: "Babesia duncani as a Model Organism to Study the Development, Virulence, and Drug Susceptibility of Intraerythrocytic Parasites In Vitro and In Vivo."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "the ability to propagate Babesia duncani both in vitro in human erythrocytes and in mice makes it a unique pathogen to study Babesia biology and pathogenesis."
    explanation: The study directly identifies B. duncani as a human-disease-relevant Babesia species used in erythrocyte and mouse systems.
- name: Babesia venatorum
  description: Human-infecting Babesia species reported particularly in Europe.
  infectious_agent_term:
    preferred_term: Babesia venatorum
    term:
      id: NCBITaxon:171411
      label: Babesia venatorum (nom. ined.)
  evidence:
  - reference: PMID:40908571
    reference_title: "Human babesiosis: The past, present and future."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "B. divergens, B. duncani, B. microti, B. venatorum"
    explanation: The current review includes B. venatorum among Babesia species known to infect humans.
agent_life_cycle:
  description: >-
    Babesia undergoes sexual reproduction in an arthropod vector and asexual
    replication in a mainly mammalian host. Human disease reflects the
    intraerythrocytic asexual phase.
  hosts:
  - preferred_term: Homo sapiens
    role: Mammalian host for the clinically relevant intraerythrocytic phase
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  - preferred_term: Ixodes scapularis
    role: Principal arthropod vector host for B. microti in the United States
    term:
      id: NCBITaxon:6945
      label: Ixodes scapularis
  vectors:
  - Black-legged tick (Ixodes scapularis)
  life_cycle_stages:
  - name: Sexual replication in the arthropod vector
    description: Sexual reproduction occurs in the tick component of the Babesia life cycle.
    evidence:
    - reference: PMID:40908571
      reference_title: "Human babesiosis: The past, present and future."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Babesiosis is caused by members of the Babesia spp., protozoan parasites whose life cycle includes sexual reproduction in the arthropod vector and asexual reproduction in the mainly mammalian host."
      explanation: The review explicitly assigns sexual and asexual replication to the vector and mammalian host, respectively.
  - name: Asexual replication in the mammalian host
    description: Asexual parasite replication occurs in the mammalian host.
    evidence:
    - reference: PMID:40908571
      reference_title: "Human babesiosis: The past, present and future."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Babesiosis is caused by members of the Babesia spp., protozoan parasites whose life cycle includes sexual reproduction in the arthropod vector and asexual reproduction in the mainly mammalian host."
      explanation: The review directly supports asexual replication in the mammalian phase.
  - name: Human intraerythrocytic phase
    description: In humans, Babesia invades and lyses erythrocytes, producing the disease-defining blood-stage pathology.
    evidence:
    - reference: PMID:28202022
      reference_title: Hematologic manifestations of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."
      explanation: Human clinical review evidence defines the clinically relevant erythrocytic phase.
  evidence:
  - reference: PMID:40908571
    reference_title: "Human babesiosis: The past, present and future."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Babesiosis is caused by members of the Babesia spp., protozoan parasites whose life cycle includes sexual reproduction in the arthropod vector and asexual reproduction in the mainly mammalian host."
    explanation: This source provides the overall two-host life-cycle framework.
transmission:
- name: Ixodid tick transmission
  description: >-
    Most human infections are acquired from hard-bodied Ixodes tick vectors,
    with regional endemicity in the northeastern and upper midwestern United
    States.
  evidence:
  - reference: PMID:34539601
    reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Most infections are transmitted by Ixodid (hard-bodied) ticks"
    explanation: The review identifies Ixodid tick bites as the main transmission route.
  - reference: PMID:28202022
    reference_title: "Hematologic manifestations of babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Babesiosis, a zoonotic parasitic infection transmitted by the Ixodes tick, has become an emerging health problem in humans that is attracting attention worldwide."
    explanation: This review also supports Ixodes tick-mediated zoonotic transmission.
- name: Transfusion-associated transmission
  description: Viable Babesia in donated blood can transmit infection to transfusion recipients.
  evidence:
  - reference: PMID:34539601
    reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "they occasionally can be spread through blood transfusion"
    explanation: The review identifies blood transfusion as an established non-vector route.
- name: Congenital and organ-transplant transmission
  description: >-
    Rare non-vector routes include perinatal transmission and transplantation
    of organs from infected donors.
  evidence:
  - reference: PMID:34539601
    reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "although they occasionally can be spread through blood transfusion and rarely via perinatal transmission and organ transplantation."
    explanation: The review identifies perinatal and organ-transplant transmission as rare routes.
epidemiology:
- name: United States reported burden, 2011–2019
  description: >-
    CDC received 16,456 reported babesiosis cases from 37 states during
    2011–2019; 98.2% came from the 10 states included in the longitudinal
    incidence analysis.
  unit: reported cases
  factors:
  - Surveillance case definitions and state reporting requirements
  - Concentration of transmission in northeastern and upper midwestern states
  evidence:
  - reference: DOI:10.15585/mmwr.mm7211a1
    reference_title: "Trends in Reported Babesiosis Cases — United States, 2011–2019"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "During 2011–2019, a total of 16,456 cases of babesiosis were reported to CDC by 37 states, including 16,174 (98.2%) reported from the 10 states included in this analysis"
    explanation: CDC surveillance provides the reported national case count and analytic-state concentration.
- name: Expanding northeastern endemicity
  description: >-
    Incidence increased significantly in eight northeastern states during
    2011–2019, with Maine, New Hampshire, and Vermont newly recognized as having
    endemic transmission comparable to other high-incidence states.
  factors:
  - Geographic expansion of Ixodes scapularis
  - Increasing infection incidence in northeastern states
  evidence:
  - reference: DOI:10.15585/mmwr.mm7211a1
    reference_title: "Trends in Reported Babesiosis Cases — United States, 2011–2019"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Incidence increased significantly in Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, and Vermont"
    explanation: The multistate surveillance analysis documents statistically significant incidence increases.
  - reference: DOI:10.15585/mmwr.mm7211a1
    reference_title: "Trends in Reported Babesiosis Cases — United States, 2011–2019"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "These three states should now be considered to have endemic transmission comparable to that in other high-incidence states"
    explanation: CDC identifies Maine, New Hampshire, and Vermont as newly endemic in this surveillance period.
prevalence:
- population: Europe
  measure_type: POINT_PREVALENCE
  prevalence_class: BELOW_1_IN_1000000
  rate_high: 0.1
  notes: >-
    Orphanet records a European point-prevalence class below 1 per 1,000,000.
    European babesiosis is caused predominantly by Babesia divergens and
    B. venatorum and is far rarer than U.S. Babesia microti infection, so this
    class should not be generalized to the endemic northeastern United States.
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "<1 / 1 000 000 | Europe | Point prevalence | OTHER"
    explanation: Orphanet provides the European point-prevalence class for babesiosis.
- population: Rhode Island, United States (2015)
  measure_type: ANNUAL_INCIDENCE
  prevalence_class: BAND_1_5_PER_10000
  rate_per_100000: 18.0
  notes: >-
    Highest single state-year reported incidence observed in CDC national
    surveillance during 2011-2019; Maine (10.3 per 100,000 in 2019) and
    Massachusetts (9.1 in 2019) were next highest. These are reported-case
    incidences, not seroprevalence or true infection rates: asymptomatic
    infections, unreported cases, and the 10 states where babesiosis is not a
    reportable condition by law are not captured, so the values are lower bounds.
  evidence:
  - reference: DOI:10.15585/mmwr.mm7211a1
    reference_title: "Trends in Reported Babesiosis Cases — United States, 2011–2019"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "reported incidences were Rhode Island (18.0 per 100,000 population in 2015), Maine (10.3 in 2019), and Massachusetts (9.1 in 2019)."
    explanation: >-
      CDC surveillance reports the highest state-level annual babesiosis
      incidences during the 2011-2019 analysis period.
environmental:
- name: Exposure to infected black-legged ticks
  influences_mechanisms:
  - target: Tick- or blood-mediated Babesia host entry
    environmental_effect: TRIGGERS
    causal_link_type: DIRECT
    description: >-
      The bite of an infected Ixodes tick inoculates sporozoites directly,
      which is the arthropod arm of this entry node and the route that
      accounts for most infections.
    evidence:
    - reference: PMID:34539601
      reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Most infections are transmitted by Ixodid (hard-bodied) ticks"
      explanation: >-
        States that most infections are transmitted by ixodid ticks,
        establishing the tick bite as the dominant route of parasite entry.
  description: >-
    Residence in or travel to endemic northeastern and upper midwestern areas
    with infected Ixodes scapularis creates the principal environmental
    acquisition risk for U.S. babesiosis.
  effect: Increases risk of tick-borne Babesia microti infection.
  evidence:
  - reference: DOI:10.15585/mmwr.mm7211a1
    reference_title: "Trends in Reported Babesiosis Cases — United States, 2011–2019"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In the United States, most babesiosis cases are caused by Babesia microti"
    explanation: >-
      CDC surveillance identifies B. microti as the dominant U.S. agent; the same
      sentence continues to name black-legged tick bites in northeastern and
      midwestern states as the transmission route. The quote is trimmed to the
      portion that is contiguous in the cached PDF text, which hyphenates
      "black-legged" across a line break.
- name: Exposure to unscreened or infected donated blood
  exposure_term:
    preferred_term: transfusion of unscreened donated blood
    term:
      id: ECTO:2000058
      label: exposure to blood transfusion
  influences_mechanisms:
  - target: Tick- or blood-mediated Babesia host entry
    environmental_effect: TRIGGERS
    causal_link_type: DIRECT
    description: >-
      Transfusion bypasses the arthropod phase entirely, delivering
      already-intraerythrocytic parasites straight into the recipient's
      circulation. It is the blood-mediated arm of the same entry node.
    evidence:
    - reference: PMID:34539601
      reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "they occasionally can be spread through blood transfusion"
      explanation: >-
        Confirms blood transfusion as a route by which the parasite is spread,
        independent of any tick exposure.
  description: >-
    Transfusion can bypass the tick vector and introduce intraerythrocytic
    parasites directly into a recipient, including recipients vulnerable to
    severe infection.
  effect: Increases risk of transfusion-transmitted babesiosis.
  evidence:
  - reference: PMID:34539601
    reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "they occasionally can be spread through blood transfusion"
    explanation: The review establishes infected blood products as an acquisition exposure.
progression:
- phase: Asymptomatic or subclinical infection
  duration: Variable; infection may be detected incidentally or through donor screening.
  notes: Many infections remain asymptomatic, particularly in immunocompetent hosts.
  evidence:
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The infection is usually asymptomatic or self-limited in the immunocompetent host"
    explanation: Human clinical review evidence supports an asymptomatic or self-limited initial course.
- phase: Acute symptomatic babesiosis
  duration: Acute febrile illness; standard treatment is generally 7–10 days in immunocompetent patients.
  notes: Fever, fatigue, headache, myalgia, hemolytic anemia, and thrombocytopenia are typical.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "infection ranges from subclinical to severe, presenting with flu-like symptoms and clinical or laboratory signs of red blood cell destruction."
    explanation: CDC describes the transition from subclinical infection to symptomatic hemolytic illness.
- phase: Severe high-burden or complicated babesiosis
  duration: Acute hospitalization; duration depends on parasite clearance and organ recovery.
  notes: Complications include DIC, respiratory distress, renal or hepatic dysfunction, altered mental status, and death.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "In severe cases, patients may exhibit thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, myocardial infarction, renal failure, hepatic compromise, altered mental status, and potentially, death."
    explanation: CDC defines the organ-complication spectrum of severe disease.
- phase: Persistent or relapsing infection
  duration: Weeks to months or longer in highly immunocompromised patients.
  notes: Impaired splenic or immune clearance can require prolonged therapy and close smear monitoring.
  evidence:
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."
    explanation: The review links impaired host defense with persistence, relapse, and life-threatening progression.
mechanistic_hypotheses:
- hypothesis_group_id: canonical_erythrocytic_disease
  hypothesis_label: Canonical intraerythrocytic replication and hemolysis model
  status: CANONICAL
  description: >-
    Human disease is driven by Babesia invasion and replication within
    erythrocytes, followed by erythrocyte lysis, anemia, systemic illness, and
    parasite-burden-associated organ complications.
  evidence:
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."
    explanation: This human clinical review directly states the central erythrocyte-invasion and lysis mechanism.
- hypothesis_group_id: host_clearance_severity_modifier
  hypothesis_label: Splenic and cell-mediated clearance modifies persistence and severity
  status: CANONICAL
  description: >-
    Splenic filtration, macrophages, CD4 T cells, and interferon-gamma support
    parasite clearance; asplenia or immunosuppression shifts the balance toward
    persistent, relapsing, or life-threatening infection.
  evidence:
  - reference: PMID:10417185
    reference_title: Roles of CD4(+) T cells and gamma interferon in protective immunity against Babesia microti infection in mice.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "These results suggest essential requirements for CD4(+) T cells and IFN-gamma in protective immunity against challenge infection with B. microti."
    explanation: Controlled mouse experiments identify CD4 T cells and interferon-gamma as protective components.
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."
    explanation: Human evidence establishes the clinical severity boundary associated with impaired splenic or immune defense.
pathophysiology:
- name: Tick- or blood-mediated Babesia host entry
  role: TRIGGER
  biological_scale: ORGANISM
  mechanism_confidence: ESTABLISHED
  description: >-
    Tick inoculation most often initiates infection, while transfusion,
    congenital transmission, and organ transplantation can introduce parasites
    without the arthropod phase.
  biological_processes:
  - preferred_term: symbiont entry into host
    term:
      id: GO:0044409
      label: symbiont entry into host
    modifier: INCREASED
  evidence:
  - reference: PMID:34539601
    reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Most infections are transmitted by Ixodid (hard-bodied) ticks"
    explanation: The review identifies the dominant initiating route.
  - reference: PMID:34539601
    reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "although they occasionally can be spread through blood transfusion and rarely via perinatal transmission and organ transplantation."
    explanation: The review establishes the alternate bloodstream-entry routes.
  downstream:
  - target: Intraerythrocytic invasion and asexual replication
    causal_link_type: DIRECT
    hypothesis_groups:
    - canonical_erythrocytic_disease
    description: Host entry seeds parasites that establish the human erythrocytic phase.
    evidence:
    - reference: PMID:28202022
      reference_title: Hematologic manifestations of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes"
      explanation: The human review directly connects infection with erythrocyte invasion.
- name: Intraerythrocytic invasion and asexual replication
  role: CENTRAL_EFFECTOR
  biological_scale: CELLULAR
  mechanism_confidence: ESTABLISHED
  description: >-
    Babesia invades human erythrocytes and replicates asexually, generating
    intraerythrocytic parasites and measurable parasitemia.
  cell_types:
  - preferred_term: erythrocyte
    term:
      id: CL:0000232
      label: erythrocyte
  biological_processes:
  - preferred_term: symbiont entry into host cell
    term:
      id: GO:0046718
      label: symbiont entry into host cell
    modifier: INCREASED
  evidence:
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Blood smear revealed intraerythrocytic Babesia, which was confirmed by PCR."
    explanation: Direct microscopy with molecular confirmation demonstrates the intraerythrocytic state.
  - reference: PMID:40908571
    reference_title: "Human babesiosis: The past, present and future."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "protozoan parasites whose life cycle includes sexual reproduction in the arthropod vector and asexual reproduction in the mainly mammalian host."
    explanation: The current review assigns asexual replication to the mammalian phase.
  downstream:
  - target: Babesia-mediated erythrocyte lysis
    causal_link_type: DIRECT
    hypothesis_groups:
    - canonical_erythrocytic_disease
    description: Intracellular parasite replication culminates in destruction of infected erythrocytes.
    evidence:
    - reference: PMID:28202022
      reference_title: Hematologic manifestations of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."
      explanation: The source directly links erythrocyte invasion to lysis.
  - target: Splenic macrophage and Th1-mediated parasite clearance
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    hypothesis_groups:
    - host_clearance_severity_modifier
    intermediate_mechanisms:
    - Recognition and removal of parasitized erythrocytes
    - CD4 T-cell and interferon-gamma activation
    description: Blood-stage infection elicits splenic and cell-mediated clearance responses.
    evidence:
    - reference: PMID:29445365
      reference_title: Babesia microti Infection Changes Host Spleen Architecture and Is Cleared by a Th1 Immune Response.
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Thus, Th1 cells-mediated immunity appears to be important in clearance of this intracellular pathogen."
      explanation: The experimental infection model supports a Th1-linked clearance response to blood-stage Babesia.
  - target: Impaired host clearance and persistent parasitemia
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    hypothesis_groups:
    - host_clearance_severity_modifier
    intermediate_mechanisms:
    - Reduced splenic filtration
    - Impaired humoral or cell-mediated immunity
    description: In vulnerable hosts, blood-stage parasites persist when splenic or immune clearance is inadequate.
    evidence:
    - reference: PMID:28202022
      reference_title: Hematologic manifestations of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."
      explanation: Human clinical evidence directly associates impaired host-defense contexts with persistence and relapse.
- name: Babesia-mediated erythrocyte lysis
  conforms_to: "hemolytic_anemia_erythrocyte_destruction#Premature Erythrocyte Destruction"
  role: CONSEQUENCE
  biological_scale: CELLULAR
  mechanism_confidence: ESTABLISHED
  description: >-
    Destruction of infected erythrocytes produces hemolysis, anemia, bilirubin
    generation, and downstream systemic manifestations. Babesiosis reaches the
    conserved premature-erythrocyte-destruction step by an infectious route:
    intraerythrocytic parasite replication lyses the host cell directly, and
    splenic macrophages additionally remove parasitized red cells. The
    destruction step, not the upstream cause, is what this entry shares with the
    hereditary and autoimmune hemolytic anemias.
  cell_types:
  - preferred_term: erythrocyte
    term:
      id: CL:0000232
      label: erythrocyte
  biological_processes:
  - preferred_term: symbiont-mediated hemolysis of host erythrocyte
    term:
      id: GO:0019836
      label: symbiont-mediated hemolysis of host erythrocyte
    modifier: INCREASED
  evidence:
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."
    explanation: The review directly links parasite-mediated erythrocyte lysis with hemolytic anemia.
  downstream:
  - target: Systemic inflammation and cytopenias
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    hypothesis_groups:
    - canonical_erythrocytic_disease
    intermediate_mechanisms:
    - Release of parasite and erythrocyte products
    - Innate immune and cytokine activation
    description: Erythrocyte destruction accompanies febrile systemic illness and hematologic abnormalities.
    evidence:
    - reference: PMID:28202022
      reference_title: Hematologic manifestations of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Full evaluation showed a febrile hemolytic anemia along with neutropenia and thrombocytopenia."
      explanation: Human clinical evidence links the hemolytic illness with fever and cytopenias.
  - target: Hemolytic anemia
    causal_link_type: DIRECT
    hypothesis_groups:
    - canonical_erythrocytic_disease
    description: Destruction of infected red cells directly produces hemolytic anemia.
    evidence:
    - reference: PMID:28202022
      reference_title: Hematologic manifestations of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "invade human erythrocytes and lyse them causing a febrile hemolytic anemia."
      explanation: The source explicitly states this causal relationship.
  - target: Jaundice
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    hypothesis_groups:
    - canonical_erythrocytic_disease
    intermediate_mechanisms:
    - Heme catabolism and bilirubin generation
    description: Hemolysis increases bilirubin production and contributes to jaundice.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0000952 | Jaundice | Frequent (79-30%)"
      explanation: Orphanet establishes frequent jaundice; the hemolysis-to-bilirubin intermediate is curated as known physiology.
- name: Splenic macrophage and Th1-mediated parasite clearance
  role: REGULATORY
  biological_scale: TISSUE
  mechanism_confidence: PROVISIONAL
  description: >-
    The spleen filters parasitized erythrocytes, while macrophage and CD4
    T-cell/IFN-gamma responses contribute to control. The detailed cellular
    mechanism is supported primarily by mouse models and is therefore not
    assumed to transfer quantitatively to humans.
  cell_types:
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  - preferred_term: CD4-positive, alpha-beta T cell
    term:
      id: CL:0000624
      label: CD4-positive, alpha-beta T cell
  evidence:
  - reference: PMID:29445365
    reference_title: Babesia microti Infection Changes Host Spleen Architecture and Is Cleared by a Th1 Immune Response.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "We confirm that spleen is important for resolution of babesiosis in mammalian hosts."
    explanation: The C3H/HeJ model supports splenic involvement in resolution.
  - reference: PMID:10417185
    reference_title: Roles of CD4(+) T cells and gamma interferon in protective immunity against Babesia microti infection in mice.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "These results suggest essential requirements for CD4(+) T cells and IFN-gamma in protective immunity against challenge infection with B. microti."
    explanation: Experimental depletion and knockout data support CD4 T-cell and interferon-gamma protection in mice.
  downstream:
  - target: Splenomegaly
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    hypothesis_groups:
    - host_clearance_severity_modifier
    intermediate_mechanisms:
    - Splenic macrophage expansion
    - Erythrophagocytosis and hematopoietic support
    description: Splenic immune and clearance activity is accompanied by organ enlargement.
    evidence:
    - reference: PMID:29445365
      reference_title: Babesia microti Infection Changes Host Spleen Architecture and Is Cleared by a Th1 Immune Response.
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "B. microti infection resulted in a significant increase in spleen sizes of mice compared to uninfected, naïve mice."
      explanation: The mouse model directly links infection-associated splenic activity with splenic enlargement.
- name: Impaired host clearance and persistent parasitemia
  role: MODIFIER
  biological_scale: ORGANISM
  mechanism_confidence: ESTABLISHED
  description: >-
    Asplenia, advanced age, and immunosuppressive disease or therapy impair
    parasite clearance, enabling persistent or relapsing infection and raising
    the risk of high parasite burden. The specific risk set is informative about
    which defenses matter: asplenia removes the filtration site for parasitized
    erythrocytes, while B-cell lymphoma and rituximab — singled out by CDC —
    implicate humoral immunity alongside the CD4/IFN-gamma cellular arm
    demonstrated in mouse models. Congestive heart failure appears on the
    severe-disease risk list as a host vulnerability, not as a manifestation.
  evidence:
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."
    explanation: Human clinical evidence supports the link between vulnerable host states and impaired clearance.
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Key risk factors for severe babesiosis and/or relapse include:"
    explanation: >-
      CDC frames these host states as drivers of severe disease and relapse,
      which is the clinical signature of impaired parasite clearance.
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Cancer (especially B-cell lymphoma or similar malignancy)"
    explanation: >-
      CDC's specific call-out of B-cell lymphoma points to humoral immunity as a
      component of clearance, complementing the T-cell evidence.
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Immunosuppressive drugs (especially rituximab)"
    explanation: >-
      Rituximab depletes CD20-positive B cells, reinforcing the humoral-immunity
      contribution to controlling blood-stage Babesia.
  downstream:
  - target: Parasitemia-associated multisystem dysfunction
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    hypothesis_groups:
    - host_clearance_severity_modifier
    intermediate_mechanisms:
    - Sustained intraerythrocytic replication
    - Accumulating hemolytic and inflammatory injury
    description: Persistent infection permits parasite burden and associated organ injury to accumulate.
    evidence:
    - reference: PMID:33179803
      reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "These results indicate a strong association between peak parasitemia level and disease severity."
      explanation: The admitted-patient cohort supports the burden-to-severity relationship.
  - target: Recurrent or relapsing infection
    causal_link_type: DIRECT
    hypothesis_groups:
    - host_clearance_severity_modifier
    description: Incomplete parasite clearance permits persistence and clinical relapse.
    evidence:
    - reference: PMID:28202022
      reference_title: Hematologic manifestations of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "follows a persistent, relapsing, and/or life threatening course"
      explanation: The review explicitly identifies persistence and relapse as outcomes of high-risk infection.
- name: Systemic inflammation and cytopenias
  role: CONSEQUENCE
  biological_scale: ORGANISM
  mechanism_confidence: PROVISIONAL
  description: >-
    Blood-stage infection and erythrocyte destruction are accompanied by
    cytokine activation and hematologic abnormalities, producing the febrile,
    flu-like syndrome and cytopenias. Cytokine-pathway detail is largely
    model-derived.
  evidence:
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Full evaluation showed a febrile hemolytic anemia along with neutropenia and thrombocytopenia."
    explanation: Human clinical evidence supports fever and cytopenias in the hemolytic illness.
  - reference: PMID:29445365
    reference_title: Babesia microti Infection Changes Host Spleen Architecture and Is Cleared by a Th1 Immune Response.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "increase in pro-inflammatory plasmatic cytokines, IL-6, IFN-γ, and TNF-α together with the presence of activated macrophage in both blood and spleen could help in resolution of infection with B. microti."
    explanation: Mouse data provide mechanistic support for inflammatory cytokine activation while also showing its potential protective role.
  downstream:
  - target: Parasitemia-associated multisystem dysfunction
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    hypothesis_groups:
    - canonical_erythrocytic_disease
    intermediate_mechanisms:
    - Coagulopathy
    - Endothelial and tissue inflammatory injury
    description: Systemic hematologic and inflammatory disturbance contributes to severe organ complications.
    evidence:
    - reference: PMID:33179803
      reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Laboratory measures indicating degrees of hemolysis, coagulopathy, and pulmonary, renal and hepatic dysfunction differed significantly across peak parasitemia levels."
      explanation: The human cohort links hematologic disturbance, coagulopathy, and organ dysfunction across parasite-burden strata.
  - target: Fever
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Pyrogenic cytokine signaling
    description: Infection-associated inflammatory signaling produces fever.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0001945 | Fever | Very frequent (99-80%)"
      explanation: Orphanet establishes fever as a very frequent manifestation of the systemic illness.
  - target: Headache
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: The febrile systemic illness frequently includes headache.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0002315 | Headache | Very frequent (99-80%)"
      explanation: Orphanet establishes headache frequency while the specific mediators remain unresolved.
  - target: Hyperhidrosis
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Fever-associated autonomic thermoregulation
    description: Febrile autonomic responses can produce sweating.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0000975 | Hyperhidrosis | Frequent (79-30%)"
      explanation: Orphanet establishes frequent hyperhidrosis within the systemic syndrome.
  - target: Thrombocytopenia
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Platelet consumption and splenic sequestration
    description: Systemic hematologic disturbance commonly lowers platelet counts.
    evidence:
    - reference: PMID:28202022
      reference_title: Hematologic manifestations of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Full evaluation showed a febrile hemolytic anemia along with neutropenia and thrombocytopenia."
      explanation: Human clinical evidence directly documents thrombocytopenia with the febrile hemolytic syndrome.
  - target: Leukopenia
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: The systemic hematologic response can include reduced circulating leukocytes.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0001882 | Leukopenia | Frequent (79-30%)"
      explanation: Orphanet establishes leukopenia as a frequent manifestation while its exact mechanism remains uncertain.
  - target: Hepatomegaly
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Reticuloendothelial activation
    - Systemic inflammatory response
    description: Reticuloendothelial and inflammatory activity can enlarge the liver.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0002240 | Hepatomegaly | Frequent (79-30%)"
      explanation: Orphanet establishes hepatomegaly as a frequent finding.
  - target: Arthralgia
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: The inflammatory flu-like syndrome commonly includes joint pain.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0002829 | Arthralgia | Frequent (79-30%)"
      explanation: Orphanet establishes arthralgia frequency; the specific mediator is not resolved.
  - target: Myalgia
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: The inflammatory flu-like syndrome commonly includes muscle pain.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0003326 | Myalgia | Frequent (79-30%)"
      explanation: Orphanet establishes myalgia frequency; the specific mediator is not resolved.
  - target: Fatigue
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Anemia
    - Systemic inflammatory signaling
    description: Anemia and systemic inflammation contribute to fatigue.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0012378 | Fatigue | Frequent (79-30%)"
      explanation: Orphanet establishes fatigue as a frequent clinical manifestation.
  - target: Cough
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: Respiratory symptoms can include cough before or without severe pulmonary dysfunction.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0012735 | Cough | Frequent (79-30%)"
      explanation: Orphanet establishes cough as a frequent clinical manifestation.
  - target: Anorexia
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Inflammatory cytokine-mediated appetite suppression
    description: Systemic inflammatory signaling can suppress appetite.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0002039 | Anorexia | Occasional (29-5%)"
      explanation: Orphanet establishes anorexia as an occasional manifestation of the systemic illness.
  - target: Nausea and vomiting
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: Systemic illness can include gastrointestinal symptoms.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0002017 | Nausea and vomiting | Occasional (29-5%)"
      explanation: Orphanet establishes nausea and vomiting as occasional manifestations.
- name: Parasitemia-associated multisystem dysfunction
  role: CONSEQUENCE
  biological_scale: ORGANISM
  mechanism_confidence: ESTABLISHED
  description: >-
    Higher peak parasitemia is strongly associated with hemolysis, coagulopathy,
    longer hospitalization, and pulmonary, renal, and hepatic dysfunction, but
    parasite percentage is not the sole determinant of organ injury.
  evidence:
  - reference: PMID:33179803
    reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "These results indicate a strong association between peak parasitemia level and disease severity."
    explanation: The hospitalized cohort directly supports parasite burden as a severity correlate.
  - reference: PMID:33179803
    reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Babesia microti parasitemia is closely associated with disease severity, though not all subjects with end-organ dysfunction had high-grade parasitemia."
    explanation: The same cohort establishes both the association and its clinically important limitation.
  downstream:
  - target: Renal insufficiency
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Hemolysis
    - Hemodynamic and inflammatory injury
    description: Severe infection can produce acute renal dysfunction.
    evidence:
    - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
      reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "In severe cases, patients may exhibit thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, myocardial infarction, renal failure, hepatic compromise, altered mental status, and potentially, death."
      explanation: CDC explicitly includes renal failure in the severe complication spectrum.
  - target: Disseminated intravascular coagulation
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Systemic coagulation activation
    description: Severe infection can trigger disseminated intravascular coagulation.
    evidence:
    - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
      reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "In severe cases, patients may exhibit thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, myocardial infarction, renal failure, hepatic compromise, altered mental status, and potentially, death."
      explanation: CDC explicitly includes DIC in the severe complication spectrum.
  - target: Respiratory insufficiency
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Acute respiratory distress
    description: Severe infection can cause pulmonary dysfunction and respiratory insufficiency.
    evidence:
    - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
      reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "In severe cases, patients may exhibit thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, myocardial infarction, renal failure, hepatic compromise, altered mental status, and potentially, death."
      explanation: CDC explicitly includes acute respiratory distress in the severe complication spectrum.
  - target: Hepatic failure
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Hemolytic and inflammatory hepatic injury
    description: Severe infection can progress from biochemical hepatic compromise to hepatic failure.
    evidence:
    - reference: PMID:33179803
      reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Laboratory measures indicating degrees of hemolysis, coagulopathy, and pulmonary, renal and hepatic dysfunction differed significantly across peak parasitemia levels."
      explanation: Human cohort data associate parasite-burden strata with hepatic dysfunction.
  - target: Myocardial infarction
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    intermediate_mechanisms:
    - Severe anemia and impaired oxygen delivery
    - Hemodynamic instability
    description: >-
      Severe hemolytic anemia and hemodynamic instability can precipitate
      myocardial infarction through demand ischemia rather than a
      Babesia-specific coronary lesion.
    evidence:
    - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
      reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "In severe cases, patients may exhibit thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, myocardial infarction, renal failure, hepatic compromise, altered mental status, and potentially, death."
      explanation: CDC lists myocardial infarction alongside hemodynamic instability in the severe complication spectrum.
  - target: Coma
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: Severe systemic disease can progress from confusion to coma.
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "HP:0001259 | Coma | Occasional (29-5%)"
      explanation: Orphanet establishes coma as an occasional severe manifestation; the mediating mechanism is unresolved.
  - target: Confusion
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: Severe systemic disease can produce altered mental status and confusion.
    evidence:
    - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
      reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "In severe cases, patients may exhibit thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, myocardial infarction, renal failure, hepatic compromise, altered mental status, and potentially, death."
      explanation: CDC explicitly includes altered mental status in the severe complication spectrum.
phenotypes:
- category: Hematologic
  name: Hemolytic anemia
  frequency: VERY_FREQUENT
  description: Hemolytic anemia is a core clinical manifestation caused by erythrocyte infection and lysis.
  phenotype_term:
    preferred_term: Hemolytic anemia
    term:
      id: HP:0001878
      label: Hemolytic anemia
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001878 | Hemolytic anemia | Very frequent (99-80%)"
    explanation: Orphanet lists hemolytic anemia as a very frequent Babesiosis phenotype.
  - reference: PMID:28202022
    reference_title: "Hematologic manifestations of babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The disease is caused by the protozoa of the genus Babesia, which invade human erythrocytes and lyse them causing a febrile hemolytic anemia."
    explanation: Human clinical review evidence supports hemolytic anemia as a direct consequence of erythrocyte lysis.
- category: Constitutional
  name: Fever
  frequency: VERY_FREQUENT
  description: Fever is a very frequent manifestation of symptomatic babesiosis.
  phenotype_term:
    preferred_term: Fever
    term:
      id: HP:0001945
      label: Fever
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001945 | Fever | Very frequent (99-80%)"
    explanation: Orphanet lists fever as a very frequent Babesiosis phenotype.
- category: Neurologic
  name: Headache
  frequency: VERY_FREQUENT
  description: Headache is a very frequent symptom in babesiosis.
  phenotype_term:
    preferred_term: Headache
    term:
      id: HP:0002315
      label: Headache
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0002315 | Headache | Very frequent (99-80%)"
    explanation: Orphanet lists headache as a very frequent Babesiosis phenotype.
- category: Hepatobiliary
  name: Jaundice
  frequency: FREQUENT
  description: Jaundice is a frequent hepatobiliary manifestation, consistent with hemolysis and hepatic involvement.
  phenotype_term:
    preferred_term: Jaundice
    term:
      id: HP:0000952
      label: Jaundice
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0000952 | Jaundice | Frequent (79-30%)"
    explanation: Orphanet lists jaundice as a frequent Babesiosis phenotype.
- category: Constitutional
  name: Hyperhidrosis
  frequency: FREQUENT
  description: Sweating or hyperhidrosis is a frequent constitutional manifestation.
  phenotype_term:
    preferred_term: Hyperhidrosis
    term:
      id: HP:0000975
      label: Hyperhidrosis
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0000975 | Hyperhidrosis | Frequent (79-30%)"
    explanation: Orphanet lists hyperhidrosis as a frequent Babesiosis phenotype.
- category: Abdominal
  name: Splenomegaly
  frequency: FREQUENT
  description: Splenomegaly is a frequent finding in babesiosis.
  phenotype_term:
    preferred_term: Splenomegaly
    term:
      id: HP:0001744
      label: Splenomegaly
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001744 | Splenomegaly | Frequent (79-30%)"
    explanation: Orphanet lists splenomegaly as a frequent Babesiosis phenotype.
- category: Hematologic
  name: Thrombocytopenia
  frequency: FREQUENT
  description: Thrombocytopenia is a common hematologic abnormality in babesiosis.
  phenotype_term:
    preferred_term: Thrombocytopenia
    term:
      id: HP:0001873
      label: Thrombocytopenia
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001873 | Thrombocytopenia | Frequent (79-30%)"
    explanation: Orphanet lists thrombocytopenia as a frequent Babesiosis phenotype.
  - reference: PMID:28202022
    reference_title: "Hematologic manifestations of babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Full evaluation showed a febrile hemolytic anemia along with neutropenia and thrombocytopenia."
    explanation: Human clinical review evidence supports thrombocytopenia with febrile hemolytic anemia.
- category: Hematologic
  name: Leukopenia
  frequency: FREQUENT
  description: Leukopenia can occur as part of the hematologic abnormality spectrum.
  phenotype_term:
    preferred_term: Leukopenia
    term:
      id: HP:0001882
      label: Decreased total leukocyte count
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001882 | Leukopenia | Frequent (79-30%)"
    explanation: Orphanet lists leukopenia as a frequent Babesiosis phenotype.
- category: Hepatobiliary
  name: Hepatomegaly
  frequency: FREQUENT
  description: Hepatomegaly is a frequent hepatobiliary finding.
  phenotype_term:
    preferred_term: Hepatomegaly
    term:
      id: HP:0002240
      label: Hepatomegaly
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0002240 | Hepatomegaly | Frequent (79-30%)"
    explanation: Orphanet lists hepatomegaly as a frequent Babesiosis phenotype.
- category: Immunologic
  name: Recurrent or relapsing infection
  frequency: FREQUENT
  description: >-
    Recurrent, relapsing, or persistent infection can occur, especially in
    splenectomized or immunosuppressed patients.
  phenotype_term:
    preferred_term: Recurrent infections
    term:
      id: HP:0002719
      label: Recurrent infections
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0002719 | Recurrent infections | Frequent (79-30%)"
    explanation: Orphanet lists recurrent infections as a frequent Babesiosis phenotype.
  - reference: PMID:28202022
    reference_title: "Hematologic manifestations of babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."
    explanation: Human clinical review evidence supports relapsing or persistent babesiosis in high-risk hosts.
- category: Musculoskeletal
  name: Arthralgia
  frequency: FREQUENT
  description: Arthralgia is a frequent musculoskeletal symptom.
  phenotype_term:
    preferred_term: Arthralgia
    term:
      id: HP:0002829
      label: Arthralgia
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0002829 | Arthralgia | Frequent (79-30%)"
    explanation: Orphanet lists arthralgia as a frequent Babesiosis phenotype.
- category: Musculoskeletal
  name: Myalgia
  frequency: FREQUENT
  description: Myalgia is a frequent symptom.
  phenotype_term:
    preferred_term: Myalgia
    term:
      id: HP:0003326
      label: Myalgia
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0003326 | Myalgia | Frequent (79-30%)"
    explanation: Orphanet lists myalgia as a frequent Babesiosis phenotype.
- category: Constitutional
  name: Fatigue
  frequency: FREQUENT
  description: Fatigue is a frequent constitutional symptom.
  phenotype_term:
    preferred_term: Fatigue
    term:
      id: HP:0012378
      label: Fatigue
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0012378 | Fatigue | Frequent (79-30%)"
    explanation: Orphanet lists fatigue as a frequent Babesiosis phenotype.
- category: Respiratory
  name: Cough
  frequency: FREQUENT
  description: Cough is a frequent respiratory symptom.
  phenotype_term:
    preferred_term: Cough
    term:
      id: HP:0012735
      label: Cough
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0012735 | Cough | Frequent (79-30%)"
    explanation: Orphanet lists cough as a frequent Babesiosis phenotype.
- category: Renal
  name: Renal insufficiency
  frequency: OCCASIONAL
  description: Renal insufficiency can occur in severe babesiosis with end-organ dysfunction.
  phenotype_term:
    preferred_term: Renal insufficiency
    term:
      id: HP:0000083
      label: Renal insufficiency
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0000083 | Renal insufficiency | Occasional (29-5%)"
    explanation: Orphanet lists renal insufficiency as an occasional Babesiosis phenotype.
  - reference: PMID:33179803
    reference_title: "Parasite burden and red blood cell exchange transfusion for babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Laboratory measures indicating degrees of hemolysis, coagulopathy, and pulmonary, renal and hepatic dysfunction differed significantly across peak parasitemia levels."
    explanation: Human clinical data link parasitemia with renal dysfunction.
- category: Hematologic
  name: Disseminated intravascular coagulation
  frequency: OCCASIONAL
  description: Disseminated intravascular coagulopathy is an occasional severe hematologic complication.
  phenotype_term:
    preferred_term: Disseminated intravascular coagulation
    term:
      id: HP:0005521
      label: Disseminated intravascular coagulation
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0005521 | Disseminated intravascular coagulation | Occasional (29-5%)"
    explanation: Orphanet lists disseminated intravascular coagulation as an occasional Babesiosis phenotype.
  - reference: PMID:28202022
    reference_title: "Hematologic manifestations of babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hematologic manifestations of the disease are common. They can range from mild anemia, to severe pancytopenia, splenic rupture, disseminated intravascular coagulopathy (DIC), or even hemophagocytic lymphohistiocytosis (HLH)."
    explanation: Human clinical review evidence supports DIC as part of the severe hematologic spectrum.
- category: Respiratory
  name: Respiratory insufficiency
  frequency: OCCASIONAL
  description: Respiratory insufficiency can occur with severe end-organ dysfunction.
  phenotype_term:
    preferred_term: Respiratory insufficiency
    term:
      id: HP:0002093
      label: Respiratory insufficiency
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0002093 | Respiratory insufficiency | Occasional (29-5%)"
    explanation: Orphanet lists respiratory insufficiency as an occasional Babesiosis phenotype.
  - reference: PMID:33179803
    reference_title: "Parasite burden and red blood cell exchange transfusion for babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Laboratory measures indicating degrees of hemolysis, coagulopathy, and pulmonary, renal and hepatic dysfunction differed significantly across peak parasitemia levels."
    explanation: Human clinical data link peak parasitemia with pulmonary dysfunction.
- category: Hepatobiliary
  name: Hepatic failure
  frequency: OCCASIONAL
  description: Hepatic failure is an occasional severe complication.
  phenotype_term:
    preferred_term: Hepatic failure
    term:
      id: HP:0001399
      label: Hepatic failure
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001399 | Hepatic failure | Occasional (29-5%)"
    explanation: Orphanet lists hepatic failure as an occasional Babesiosis phenotype.
  - reference: PMID:33179803
    reference_title: "Parasite burden and red blood cell exchange transfusion for babesiosis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Laboratory measures indicating degrees of hemolysis, coagulopathy, and pulmonary, renal and hepatic dysfunction differed significantly across peak parasitemia levels."
    explanation: Human clinical data link peak parasitemia with hepatic dysfunction.
- category: Neurologic
  name: Confusion
  frequency: OCCASIONAL
  description: Confusion is an occasional neurologic manifestation of severe disease.
  phenotype_term:
    preferred_term: Confusion
    term:
      id: HP:0001289
      label: Confusion
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001289 | Confusion | Occasional (29-5%)"
    explanation: Orphanet lists confusion as an occasional Babesiosis phenotype.
- category: Cardiovascular
  name: Myocardial infarction
  frequency: OCCASIONAL
  description: >-
    Myocardial infarction is reported among the severe complications of
    babesiosis, plausibly reflecting the combination of profound hemolytic
    anemia, hemodynamic instability, and systemic inflammatory activation
    rather than a Babesia-specific coronary mechanism.
  phenotype_term:
    preferred_term: Myocardial infarction
    term:
      id: HP:0001658
      label: Myocardial infarction
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001658 | Myocardial infarction | Occasional (29-5%)"
    explanation: Orphanet lists myocardial infarction as an occasional Babesiosis phenotype.
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "In severe cases, patients may exhibit thrombocytopenia, disseminated intravascular coagulation, hemodynamic instability, acute respiratory distress, myocardial infarction, renal failure, hepatic compromise, altered mental status, and potentially, death."
    explanation: CDC independently includes myocardial infarction in the severe complication spectrum.
- category: Neurologic
  name: Coma
  frequency: OCCASIONAL
  description: >-
    Coma represents the severe end of the altered-mental-status spectrum in
    complicated babesiosis.
  phenotype_term:
    preferred_term: Coma
    term:
      id: HP:0001259
      label: Coma
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0001259 | Coma | Occasional (29-5%)"
    explanation: Orphanet lists coma as an occasional Babesiosis phenotype.
- category: Gastrointestinal
  name: Anorexia
  frequency: OCCASIONAL
  description: Loss of appetite can accompany the febrile systemic illness.
  phenotype_term:
    preferred_term: Anorexia
    term:
      id: HP:0002039
      label: Anorexia
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0002039 | Anorexia | Occasional (29-5%)"
    explanation: Orphanet lists anorexia as an occasional Babesiosis phenotype.
- category: Gastrointestinal
  name: Nausea and vomiting
  frequency: OCCASIONAL
  description: Nausea and vomiting can occur as gastrointestinal symptoms.
  phenotype_term:
    preferred_term: Nausea and vomiting
    term:
      id: HP:0002017
      label: Nausea and vomiting
  evidence:
  - reference: ORPHA:108
    reference_title: "Babesiosis"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "HP:0002017 | Nausea and vomiting | Occasional (29-5%)"
    explanation: Orphanet lists nausea and vomiting as an occasional Babesiosis phenotype.
histopathology:
- name: Intraerythrocytic Babesia on peripheral blood smear
  description: >-
    Giemsa-stained peripheral blood may show intraerythrocytic Babesia forms;
    careful manual review and species-aware confirmation are important because
    low parasitemia, Plasmodium, and staining artifacts can complicate
    interpretation.
  finding_term:
    preferred_term: Intraerythrocytic Babesia parasite present
    term:
      id: NCIT:C120903
      label: Parasite Present
  diagnostic: true
  evidence:
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Blood smear revealed intraerythrocytic Babesia, which was confirmed by PCR."
    explanation: Human clinical evidence directly documents the diagnostic microscopic finding.
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "When considering a babesiosis diagnosis, healthcare providers should explicitly request a manual (non-automated) review of the peripheral blood smear."
    explanation: CDC specifically recommends manual smear review when babesiosis is suspected.
biochemical:
- name: Peripheral blood parasitemia
  presence: INCREASED
  context: >-
    The fraction of infected erythrocytes is a dynamic measure of parasite
    burden. Higher peak parasitemia correlates with severity, but clinical
    status and organ dysfunction must be assessed independently.
  readouts:
  - target: Intraerythrocytic invasion and asexual replication
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: The infected-erythrocyte fraction reports the burden of the intraerythrocytic parasite phase.
    evidence:
    - reference: PMID:33179803
      reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Subjects were stratified according to peak parasitemia: <1% (n = 34), 1-5% (n = 24), 5-10% (n = 15), and >10% (n = 18)."
      explanation: The clinical cohort quantifies blood-stage burden as the percentage parasitemia.
  - target: Parasitemia-associated multisystem dysfunction
    relationship: CORRELATES_WITH
    direction: POSITIVE
    endpoint_context: PROGNOSTIC
    interpretation: Increasing peak parasitemia generally tracks with increasing disease severity, but is not sufficient alone for risk classification.
    evidence:
    - reference: PMID:33179803
      reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Babesia microti parasitemia is closely associated with disease severity, though not all subjects with end-organ dysfunction had high-grade parasitemia."
      explanation: The cohort supports a positive but imperfect severity relationship.
  evidence:
  - reference: PMID:33179803
    reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "These results indicate a strong association between peak parasitemia level and disease severity."
    explanation: Human inpatient data establish parasitemia as a severity-associated blood marker.
- name: Hemolytic laboratory pattern
  presence: INCREASED
  context: >-
    Anemia with laboratory evidence of erythrocyte destruction is a core
    disease readout; thrombocytopenia and elevations in liver enzymes, blood
    urea nitrogen, or creatinine can accompany more complicated illness.
  readouts:
  - target: Babesia-mediated erythrocyte lysis
    relationship: READOUT_OF
    direction: POSITIVE
    endpoint_context: DIAGNOSTIC
    interpretation: Laboratory evidence of red-cell destruction reports the hemolytic mechanism.
    evidence:
    - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
      reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "For acutely ill patients, the findings on routine laboratory testing frequently include hemolytic anemia and thrombocytopenia."
      explanation: CDC identifies hemolytic anemia as a frequent laboratory finding in acute illness.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "For acutely ill patients, the findings on routine laboratory testing frequently include hemolytic anemia and thrombocytopenia."
    explanation: CDC directly supports the characteristic acute laboratory pattern.
- name: Babesia DNA detected by nucleic acid amplification
  presence: POSITIVE
  context: >-
    Babesia PCR supports direct detection, including when organism burden is
    below the reliable threshold of routine microscopy or when treatment
    response and persistence require molecular assessment.
  readouts:
  - target: Intraerythrocytic invasion and asexual replication
    relationship: READOUT_OF
    direction: PRESENT_ABSENT
    endpoint_context: DIAGNOSTIC
    interpretation: Babesia DNA in blood directly reports current or recently active blood-stage infection in the appropriate clinical context.
    evidence:
    - reference: PMID:28202022
      reference_title: Hematologic manifestations of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Blood smear revealed intraerythrocytic Babesia, which was confirmed by PCR."
      explanation: Human clinical evidence uses PCR to confirm the smear-defined blood-stage infection.
  - target: Impaired host clearance and persistent parasitemia
    relationship: READOUT_OF
    direction: PRESENT_ABSENT
    endpoint_context: MONITORING
    interpretation: Persistent Babesia DNA can reveal residual infection when smear parasitemia is difficult to detect.
    evidence:
    - reference: PMID:29445365
      reference_title: Babesia microti Infection Changes Host Spleen Architecture and Is Cleared by a Th1 Immune Response.
      supports: SUPPORT
      evidence_source: MODEL_ORGANISM
      snippet: "Although parasitemia was undetectable by microscopy at 21 days of infection, detection of B. microti DNA by our qPCR supports possibility of continuing low-level infection."
      explanation: Mouse-model evidence demonstrates molecular detection of low-level persistence after smear negativity; human monitoring implications remain inferential.
  evidence:
  - reference: PMID:34539601
    reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Diagnosis is usually confirmed by blood smear or polymerase chain reaction (PCR)."
    explanation: The review identifies PCR as a standard confirmatory method.
clinical_burden:
  burden_level: VARIABLE
  rationale: >-
    Many infections are asymptomatic or self-limited, but asplenic,
    immunocompromised, and older patients can develop persistent parasitemia,
    severe hemolysis, multiorgan failure, prolonged treatment needs, and death.
  evidence:
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The infection is usually asymptomatic or self-limited in the immunocompetent host, or follows a persistent, relapsing, and/or life threatening course with multi-organ failure, mainly in the splenectomized or immunosuppressed patients."
    explanation: The review directly supports the strongly variable burden assignment.
diagnosis:
- name: Manual peripheral blood-smear examination
  description: >-
    Request manual light-microscopic review of peripheral blood smears for
    intraerythrocytic Babesia. Multiple smears may be required at low burden,
    and expert review may be needed to distinguish Babesia from Plasmodium or
    artifacts.
  diagnosis_term:
    preferred_term: blood smear test
    term:
      id: NCIT:C25294
      label: Laboratory Procedure
  results: Intraerythrocytic Babesia forms support active infection; species confirmation may require molecular testing.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "When considering a babesiosis diagnosis, healthcare providers should explicitly request a manual (non-automated) review of the peripheral blood smear."
    explanation: CDC specifically recommends manual rather than automated smear review.
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "parasites through light-microscopic examination of blood smears, though sometimes multiple smears may need to be examined."
    explanation: CDC supports microscopy and repeat-smear review when necessary.
- name: Babesia nucleic acid amplification testing
  description: >-
    PCR or another validated nucleic acid amplification test confirms Babesia
    DNA in blood and is particularly useful when smear burden is low or species
    resolution is needed.
  diagnosis_term:
    preferred_term: nucleic acid amplification testing
    term:
      id: NCIT:C20055
      label: Nucleic Acid Amplification Test
  results: A positive species-appropriate Babesia nucleic acid test supports active or recently active infection in clinical context.
  evidence:
  - reference: PMID:34539601
    reference_title: "Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Diagnosis is usually confirmed by blood smear or polymerase chain reaction (PCR)."
    explanation: The review identifies PCR as a usual confirmatory modality.
  - reference: PMID:28202022
    reference_title: Hematologic manifestations of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Blood smear revealed intraerythrocytic Babesia, which was confirmed by PCR."
    explanation: A human clinical example demonstrates molecular confirmation of smear findings.
- name: Babesia serology as supportive testing
  description: >-
    Species-appropriate serology can support exposure assessment or diagnosis,
    but it should be interpreted with direct-detection tests because antibodies
    may persist and immunocompromised patients may mount weak responses.
  diagnosis_term:
    preferred_term: serology testing
    term:
      id: NCIT:C25294
      label: Laboratory Procedure
  results: Positive Babesia-specific antibodies support exposure; direct detection is preferred for acute active infection.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "by blood-smear examination and, if indicated, by other means, such as molecular and/or serologic methods tailored to the setting/species."
    explanation: CDC supports serology as a context- and species-tailored adjunct to direct examination.
differential_diagnoses:
- name: Malaria
  description: >-
    Malaria can cause a febrile intraerythrocytic parasitemia with anemia and
    may resemble babesiosis on thin blood smear, particularly when ring forms
    are sparse.
  disease_term:
    preferred_term: malaria
    term:
      id: MONDO:0005136
      label: malaria
  distinguishing_features:
  - Travel or residence in a malaria-endemic area shifts the pretest probability.
  - Expert morphology, species-specific PCR, and appropriate rapid antigen tests distinguish Plasmodium from Babesia.
  - Babesia can show tetrads, while Plasmodium has species-specific pigment and developmental forms.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Distinguishing <em>Babesia</em> and <em>Plasmodium</em> parasites (especially <em>P. falciparum</em>) and artifacts like stain or platelet debris can be challenging."
    explanation: CDC explicitly identifies Plasmodium as a microscopic diagnostic challenge.
- name: Human granulocytic anaplasmosis
  description: >-
    Anaplasmosis shares Ixodes scapularis exposure, fever, headache, myalgia,
    leukopenia, and thrombocytopenia with babesiosis, and coinfection can occur.
  distinguishing_features:
  - Hemolytic anemia and intraerythrocytic parasites favor babesiosis.
  - Species-specific blood PCR distinguishes Babesia from Anaplasma phagocytophilum.
  - Detection of granulocytic morulae supports anaplasmosis rather than babesiosis.
  evidence:
  - reference: PMID:40908571
    reference_title: "Human babesiosis: The past, present and future."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "B. microti, Borrelia burgdorferi and Anaplasma phagocytophilum are all transmitted by black-legged ticks ( Ixodes scapularis) and therefore co-infection is likely and has been reported."
    explanation: The review establishes shared vector exposure and the possibility of coinfection.
  - reference: DOI:10.15585/mmwr.mm7211a1
    reference_title: "Trends in Reported Babesiosis Cases — United States, 2011–2019"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "other tickborne conditions can have similar clinical manifestations, risk for disease acquisition, and geographic distribution"
    explanation: CDC surveillance guidance supports considering clinically overlapping tick-borne conditions.
treatments:
- name: Atovaquone plus azithromycin pharmacotherapy
  action_category: THERAPEUTIC
  therapeutic_modality: SMALL_MOLECULE
  description: >-
    Atovaquone plus azithromycin is the preferred combination for most
    symptomatic babesiosis. A randomized trial in non-life-threatening disease
    found efficacy comparable to clindamycin plus quinine with fewer adverse
    reactions.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: atovaquone
      term:
        id: CHEBI:575568
        label: atovaquone
    - preferred_term: azithromycin
      term:
        id: CHEBI:2955
        label: azithromycin
  target_mechanisms:
  - target: Intraerythrocytic invasion and asexual replication
    treatment_effect: INHIBITS
    description: Combination antimicrobial therapy suppresses the replicating blood-stage parasite burden.
    evidence:
    - reference: PMID:11078770
      reference_title: Atovaquone and azithromycin for the treatment of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "For the treatment of babesiosis, a regimen of atovaquone and azithromycin is as effective as a regimen of clindamycin and quinine"
      explanation: Randomized human treatment evidence supports activity against clinical Babesia infection.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html
    reference_title: "Clinical Care of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "atovaquone <strong>PLUS</strong> azithromycin (preferred)"
    explanation: CDC identifies this as the preferred typical combination.
  - reference: PMID:11078770
    reference_title: Atovaquone and azithromycin for the treatment of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CONCLUSIONS: For the treatment of babesiosis, a regimen of atovaquone and azithromycin is as effective as a regimen of clindamycin and quinine and is associated with fewer adverse reactions."
    explanation: The randomized trial supports efficacy and better tolerability in non-life-threatening disease.
- name: Clindamycin plus quinine pharmacotherapy
  action_category: THERAPEUTIC
  therapeutic_modality: SMALL_MOLECULE
  description: >-
    Clindamycin plus quinine is an alternative combination, including when the
    preferred regimen cannot be used; the randomized comparison documented a
    substantially higher adverse-effect burden.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: clindamycin
      term:
        id: CHEBI:3745
        label: clindamycin
    - preferred_term: quinine
      term:
        id: CHEBI:15854
        label: quinine
  target_mechanisms:
  - target: Intraerythrocytic invasion and asexual replication
    treatment_effect: INHIBITS
    description: Combination antimicrobial therapy suppresses the replicating blood-stage parasite burden.
    evidence:
    - reference: PMID:11078770
      reference_title: Atovaquone and azithromycin for the treatment of babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "A course of clindamycin and quinine is the standard treatment"
      explanation: The randomized clinical trial identifies this as an active comparator regimen.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html
    reference_title: "Clinical Care of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "clindamycin <strong>PLUS</strong> quinine* (alternative)"
    explanation: CDC identifies this combination as the typical alternative.
  - reference: PMID:11078770
    reference_title: Atovaquone and azithromycin for the treatment of babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Adverse effects were reported by 15 percent of the subjects who received atovaquone and azithromycin, as compared with 72 percent of those who received clindamycin and quinine (P<0.001)."
    explanation: The trial quantifies the adverse-effect tradeoff.
- name: Prolonged combination therapy for highly immunocompromised patients
  action_category: THERAPEUTIC
  therapeutic_modality: SMALL_MOLECULE
  description: >-
    Highly immunocompromised patients may need at least six consecutive weeks
    of combination therapy, close clinical and laboratory follow-up, and
    continuation until blood smears are negative for two consecutive weeks.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
  target_mechanisms:
  - target: Impaired host clearance and persistent parasitemia
    treatment_effect: INHIBITS
    description: Extended antimicrobial exposure compensates for impaired host clearance and suppresses persistent parasites.
    evidence:
    - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html
      reference_title: "Clinical Care of Babesiosis | Babesiosis | CDC"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "For highly immunocompromised patients, treatment may be required for at least 6 consecutive weeks or longer."
      explanation: CDC directly links prolonged treatment duration to the high-risk host context.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html
    reference_title: "Clinical Care of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Treatment should be continued until parasites are no longer detected on smears for 2 consecutive weeks."
    explanation: CDC provides the smear-guided stopping criterion for highly immunocompromised patients.
- name: Red blood cell exchange transfusion for selected severe babesiosis
  action_category: THERAPEUTIC
  description: >-
    Red blood cell exchange may be considered with high-grade parasitemia or
    substantial parasite burden accompanied by severe hemolytic anemia or
    pulmonary, renal, or hepatic decline. Parasitemia must be interpreted with
    clinical status.
  treatment_term:
    preferred_term: blood transfusion
    term:
      id: NCIT:C15192
      label: Blood Transfusion
  target_mechanisms:
  - target: Intraerythrocytic invasion and asexual replication
    treatment_effect: INHIBITS
    description: Exchange physically removes parasite-infected erythrocytes and lowers circulating blood-stage burden.
    evidence:
    - reference: PMID:33179803
      reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Nineteen subjects underwent RCE, all with peak parasitemia ≥9% and some degree of end-organ dysfunction."
      explanation: The clinical series documents exchange use in high-burden infection.
  - target: Parasitemia-associated multisystem dysfunction
    treatment_effect: INHIBITS
    description: Rapid burden reduction is intended to mitigate ongoing severe hemolytic and organ injury.
    evidence:
    - reference: PMID:33179803
      reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Our data suggest that the use of parasitemia >10%, coupled with clinical status, is a reasonable indicator for RCE in babesiosis patients."
      explanation: Human cohort evidence supports integrating parasite burden with organ-level clinical status.
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html
    reference_title: "Clinical Care of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Exchange transfusions in which portions of a patient's blood or blood cells are replaced with transfused blood components"
    explanation: CDC includes exchange transfusion among supportive interventions for selected severe illness.
  - reference: PMID:33179803
    reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Babesia microti parasitemia is closely associated with disease severity, though not all subjects with end-organ dysfunction had high-grade parasitemia."
    explanation: The cohort cautions against using a numeric parasite threshold without clinical assessment.
- name: Tick-bite avoidance counseling
  action_category: COUNSELING_INFORMATIONAL
  therapeutic_modality: BEHAVIORAL
  description: >-
    No babesiosis vaccine exists, so primary prevention rests entirely on
    interrupting the tick-exposure step: avoiding tick habitat, using
    repellents, wearing covering clothing, and performing tick self-checks.
    Successful avoidance acts upstream of the host-entry trigger by preventing
    the inoculation event itself, though it is the patient's resulting behavior
    rather than the advice that interrupts transmission. Tick avoidance does
    not address the transfusion, transplant, or congenital routes, which is why
    donor screening matters independently.
  treatment_term:
    preferred_term: tick-bite avoidance counseling
    term:
      id: NCIT:C181743
      label: Behavioral Counseling
  evidence:
  - reference: url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html
    reference_title: "Clinical Overview of Babesiosis | Babesiosis | CDC"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "There is no vaccine for babesiosis. Encourage patients to avoid ticks, use tick repellents, wear socks, long-sleeved shirts, and pants, and perform self-checks for the presence of ticks."
    explanation: CDC directly states the absence of a vaccine and the recommended personal protective measures.
clinical_trials:
- name: NCT06207370
  phase: PHASE_II
  status: RECRUITING
  description: >-
    Double-blind, randomized, multisite, placebo-controlled Phase II trial of
    oral tafenoquine versus placebo added to atovaquone/azithromycin standard
    care in 33 estimated hospitalized participants at low risk for relapse.
    Registry status was checked 2026-07-23; estimated completion is July 2027.
  evidence:
  - reference: clinicaltrials:NCT06207370
    reference_title: A Double-blind Placebo-controlled Study to Assess the Safety and Efficacy of Oral Tafenoquine Plus Standard of Care Versus Placebo Plus Standard of Care in Patients Hospitalized for Babesiosis
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This study is a double-blind, randomized, multisite, placebo-controlled trial comparing the safety and efficacy of TQ versus placebo in patients hospitalized for babesiosis with low risk for relapsing disease"
    explanation: The registry summary directly supports the interventional design and enrolled disease context.
- name: NCT07345988
  phase: NOT_APPLICABLE
  status: RECRUITING
  description: >-
    Retrospective multicenter observational study describing epidemiologic,
    clinical, biological, treatment, and prognostic characteristics of an
    estimated 100 human babesiosis cases in metropolitan France. Registry
    status was checked 2026-07-23; estimated completion is May 2027.
  evidence:
  - reference: clinicaltrials:NCT07345988
    reference_title: "Human Babesiosis in Metropolitan France: a Retrospective and Multicenter Descriptive Analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The aim of this study is to describe the epidemiological, clinical, biological, therapeutic, and prognostic characteristics of human babesiosis cases diagnosed in metropolitan France."
    explanation: The registry summary directly states the observational study objective.
- name: NCT01528449
  phase: PHASE_III
  status: COMPLETED
  description: >-
    Completed prospective and retrospective study of 90,116 blood donors using
    real-time PCR and indirect fluorescent antibody assays for B. microti
    screening.
  evidence:
  - reference: clinicaltrials:NCT01528449
    reference_title: Blood Donation Screening for Babesia Microti by Real-time Polymerase Chain Reaction (PCR) and by Indirect Flourescent Antibody (IFA) Assays  # codespell:ignore-line
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Both prospective and retrospective (look back) study of blood donors for laboratory evidence of babesia microti infection."
    explanation: The registry summary establishes the donor-screening study population and design.
animal_models:
- species: Mus musculus
  background: C3H/HeJ
  category: Experimental infection
  description: >-
    Susceptible C3H/HeJ mice infected with B. microti develop high parasitemia,
    a sharp hemoglobin decrease, splenic enlargement and architectural change,
    macrophage expansion, and Th1-associated clearance.
  associated_phenotypes:
  - Hemolytic anemia
  - Splenomegaly
  evidence:
  - reference: PMID:29445365
    reference_title: Babesia microti Infection Changes Host Spleen Architecture and Is Cleared by a Th1 Immune Response.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Susceptible C3H/HeJ mice show several human-like disease manifestations and are ideal to study pathogenesis of Babesia species."
    explanation: The authors explicitly frame this strain as a pathogenesis model with human-like manifestations.
  - reference: PMID:29445365
    reference_title: Babesia microti Infection Changes Host Spleen Architecture and Is Cleared by a Th1 Immune Response.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Peak parasitemia of 42.5% was immediately followed by diminished hemoglobin level."
    explanation: The model reproduces parasite-burden-associated anemia.
- species: Mus musculus
  background: BALB/c
  category: Protective-immunity challenge model
  description: >-
    Recovered BALB/c mice resist B. microti rechallenge; CD4 depletion,
    interferon-gamma neutralization, and interferon-gamma deficiency test the
    cellular requirements for protection.
  associated_phenotypes:
  - Recurrent or relapsing infection
  evidence:
  - reference: PMID:10417185
    reference_title: Roles of CD4(+) T cells and gamma interferon in protective immunity against Babesia microti infection in mice.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "BALB/c mice which recovered from primary infection showed strong protective immunity against challenge infection."
    explanation: Rechallenge directly demonstrates acquired protection in this mouse background.
  - reference: PMID:10417185
    reference_title: Roles of CD4(+) T cells and gamma interferon in protective immunity against Babesia microti infection in mice.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "These results suggest essential requirements for CD4(+) T cells and IFN-gamma in protective immunity against challenge infection with B. microti."
    explanation: Perturbation experiments identify required protective immune components.
- species: Mus musculus
  background: C3H/HeJ
  category: Babesia duncani in-culture-in-mouse lethal infection model
  description: >-
    The B. duncani ICIM system couples continuous growth in human erythrocytes
    to reproducible lethal infection in mice for virulence and drug-response
    studies.
  associated_phenotypes:
  - Hemolytic anemia
  evidence:
  - reference: PMID:35512141
    reference_title: "Babesia duncani as a Model Organism to Study the Development, Virulence, and Drug Susceptibility of Intraerythrocytic Parasites In Vitro and In Vivo."
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "Here we report an optimized B. duncani in culture-in mouse (ICIM) model that combines continuous in vitro culture of the parasite with a precise model of lethal infection in mice."
    explanation: The study directly defines the linked in-vitro/in-vivo model.
experimental_models:
- name: Continuous Babesia duncani culture in human erythrocytes
  experimental_model_type: PRIMARY_CELL_CULTURE
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  cell_types:
  - preferred_term: erythrocyte
    term:
      id: CL:0000232
      label: erythrocyte
  cell_source: Human erythrocytes
  culture_system: Continuous in-vitro propagation of Babesia duncani in human erythrocytes
  conditions:
  - Babesia duncani-infected erythrocytes
  publication: PMID:35512141
  description: >-
    A continuous human-erythrocyte culture system supports B. duncani
    development and drug-susceptibility testing and connects to a controlled
    mouse infection model.
  modeled_mechanisms:
  - target: Intraerythrocytic invasion and asexual replication
    description: The primary-cell system directly propagates and measures the human erythrocytic parasite phase.
    evidence:
    - reference: PMID:35512141
      reference_title: "Babesia duncani as a Model Organism to Study the Development, Virulence, and Drug Susceptibility of Intraerythrocytic Parasites In Vitro and In Vivo."
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "the ability to propagate Babesia duncani both in vitro in human erythrocytes and in mice makes it a unique pathogen to study Babesia biology and pathogenesis."
      explanation: The source explicitly supports propagation of the intraerythrocytic phase in human cells.
  evidence:
  - reference: PMID:35512141
    reference_title: "Babesia duncani as a Model Organism to Study the Development, Virulence, and Drug Susceptibility of Intraerythrocytic Parasites In Vitro and In Vivo."
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Here we report an optimized B. duncani in culture-in mouse (ICIM) model that combines continuous in vitro culture of the parasite with a precise model of lethal infection in mice."
    explanation: The source directly describes the continuous culture component and its model linkage.
datasets:
- accession: sra:SRP058536
  title: Whole-genome capture sequences from 25 Babesia microti isolates
  description: >-
    Multiplex hybrid-capture sequence data from 25 B. microti isolates obtained
    from Ixodes scapularis and human blood across U.S. sampling sites, used to
    characterize genome-wide diversity and northeastern population structure.
  organism:
    preferred_term: Babesia microti
    term:
      id: NCBITaxon:5868
      label: Babesia microti
  data_type: WGS
  sample_types:
  - preferred_term: Ixodes scapularis-derived Babesia microti isolate
    term:
      id: NCBITaxon:6945
      label: Ixodes scapularis
  - preferred_term: human-blood-derived Babesia microti isolate
    term:
      id: UBERON:0000178
      label: blood
    tissue_term:
      preferred_term: blood
      term:
        id: UBERON:0000178
        label: blood
  sample_count: 25
  conditions:
  - Tick-derived Babesia microti
  - Human-infecting Babesia microti
  platform: Multiplexed hybrid capture and genome sequencing
  publication: PMID:27821055
  evidence:
  - reference: PMID:27821055
    reference_title: Babesia microti from humans and ticks hold a genomic signature of strong population structure in the United States.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "we used multiplexed hybrid capture of 25 B. microti isolates obtained from I. scapularis and human blood."
    explanation: The publication directly states the dataset design, isolate count, and sources.
  - reference: PMID:27821055
    reference_title: Babesia microti from humans and ticks hold a genomic signature of strong population structure in the United States.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Metadata and sequence data of each sample in this study were submitted to NCBI Short Read Archive"
    explanation: The data-availability statement supports public SRA deposition.
discussions:
- discussion_id: gap_babesiosis_severity_beyond_parasitemia
  prompt: >-
    Which host, parasite, inflammatory, and organ-specific factors explain
    severe end-organ dysfunction when peripheral parasitemia is not high?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Parasitemia-associated multisystem dysfunction
  rationale: >-
    Peak parasitemia correlates strongly with severity and informs exchange
    transfusion decisions, but some patients with organ dysfunction lack
    high-grade parasitemia. A parasite-percentage threshold therefore cannot
    fully represent tissue injury, host vulnerability, or timing.
  evidence:
  - reference: PMID:33179803
    reference_title: Parasite burden and red blood cell exchange transfusion for babesiosis.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Babesia microti parasitemia is closely associated with disease severity, though not all subjects with end-organ dysfunction had high-grade parasitemia."
    explanation: The human cohort directly identifies the unresolved mismatch between circulating burden and organ injury.
- discussion_id: gap_babesiosis_tafenoquine_translation
  prompt: >-
    Can tafenoquine be used safely and effectively as an adjunct to standard
    care for human babesiosis, and which regimen prevents relapse without
    unacceptable hemolytic risk?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - clinical_trials#NCT06207370
  - pathophysiology#Impaired host clearance and persistent parasitemia
  rationale: >-
    Tafenoquine plus atovaquone cures B. microti and B. duncani mouse models,
    and a small human relapsing-babesiosis series suggests adjunctive activity,
    but tafenoquine monotherapy failed in one case. A recruiting randomized
    Phase II add-on trial is testing hospitalized patients at low relapse risk;
    efficacy, optimal combinations, immunocompromised-host use, resistance, and
    G6PD-related safety remain unresolved.
  evidence:
  - reference: PMID:38169301
    reference_title: Tafenoquine-Atovaquone Combination Achieves Radical Cure and Confers Sterile Immunity in Experimental Models of Human Babesiosis.
    supports: SUPPORT
    evidence_source: MODEL_ORGANISM
    snippet: "We further show that a combination of tafenoquine and atovaquone achieves cure with no recrudescence in both models of human babesiosis."
    explanation: Preclinical evidence supports the combination but does not establish human efficacy.
  - reference: PMID:38814096
    reference_title: "Tafenoquine for Relapsing Babesiosis: A Case Series."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "In 1 case, tafenoquine was administered alone and failed to prevent relapse."
    explanation: The case series identifies a clinically important monotherapy limitation.
  - reference: clinicaltrials:NCT06207370
    reference_title: A Double-blind Placebo-controlled Study to Assess the Safety and Efficacy of Oral Tafenoquine Plus Standard of Care Versus Placebo Plus Standard of Care in Patients Hospitalized for Babesiosis
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "This study is a double-blind, randomized, multisite, placebo-controlled trial comparing the safety and efficacy of TQ versus placebo in patients hospitalized for babesiosis"
    explanation: The active trial directly addresses adjunctive human efficacy and safety.
classifications:
  harrisons_chapter:
  - classification_value: INFECTIOUS_DISEASES
    evidence:
    - reference: ORPHA:108
      reference_title: Babesiosis
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Babesiosis is an infectious disease caused by protozoa of the genus <i>Babesia</i>"
      explanation: Orphanet explicitly classifies babesiosis as a protozoal infectious disease.
review_notes: >-
  Re-reviewed 2026-07-23. This entry models human babesiosis across Babesia
  species while distinguishing U.S. B. microti epidemiology from broader
  species biology. Human clinical evidence anchors erythrocyte invasion,
  hemolysis, host-risk modifiers, severity, diagnosis, and treatment. Mouse and
  in-vitro evidence is labeled explicitly and is not treated as quantitative
  human proof. Tafenoquine remains investigational for babesiosis; it is
  represented in a recruiting trial and discussion rather than as established
  therapy. Surveillance counts are reported-case counts and should not be read
  as population prevalence.

  Updated 2026-07-29. Added the previously absent structured `prevalence` block
  (Orphanet European point prevalence; CDC peak U.S. state annual reported
  incidence, explicitly flagged as a reported-case lower bound rather than a
  true infection rate). Declared conformance of the erythrocyte-lysis node to
  `hemolytic_anemia_erythrocyte_destruction#Premature Erythrocyte Destruction`,
  which places babesiosis alongside the hereditary and autoimmune hemolytic
  anemias at the shared destruction step while keeping the infectious upstream
  cause distinct. Added the severe-disease phenotypes myocardial infarction,
  coma, and anorexia with matching causal edges. Congestive heart failure and
  venous thrombosis/hypercoagulability appear in the Orphanet phenotype table
  but were deliberately NOT added as manifestations: CDC lists congestive heart
  failure as a predisposing risk factor for severe disease, so asserting it as
  a consequence would invert the causal direction. Photophobia, depression,
  recurrent pharyngitis, limitation of joint mobility, and clinodactyly of the
  5th toe were also left out as implausible for an acute protozoal infection
  and most likely Orphanet annotation noise. Tick-bite avoidance counseling was
  added as the one previously missing arm of management (there is no babesiosis
  vaccine), classified COUNSELING_INFORMATIONAL and deliberately carrying no
  `target_mechanisms` edge: informational actions do not themselves act on the
  pathograph, so the mechanistic link is stated in prose instead. One
  pre-existing MMWR snippet was
  trimmed because PDF line-break hyphenation of "black-legged" meant the quoted
  string was not actually contiguous in the cached text; this went undetected
  because `DOI:` is in the reference validator's skip_prefixes.

📚

References & Deep Research

References

18

ORPHA:108

Babesiosis

No top-level findings curated for this source.

PMID:34539601

Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis.

No top-level findings curated for this source.

PMID:28202022

Hematologic manifestations of babesiosis.

No top-level findings curated for this source.

PMID:11078770

Atovaquone and azithromycin for the treatment of babesiosis.

No top-level findings curated for this source.

PMID:33179803

Parasite burden and red blood cell exchange transfusion for babesiosis.

No top-level findings curated for this source.

PMID:40908571

Human babesiosis: The past, present and future.

No top-level findings curated for this source.

DOI:10.15585/mmwr.mm7211a1

Trends in Reported Babesiosis Cases — United States, 2011–2019

No top-level findings curated for this source.

PMID:27821055

Babesia microti from humans and ticks hold a genomic signature of strong population structure in the United States.

No top-level findings curated for this source.

PMID:29445365

Babesia microti Infection Changes Host Spleen Architecture and Is Cleared by a Th1 Immune Response.

No top-level findings curated for this source.

PMID:10417185

Roles of CD4(+) T cells and gamma interferon in protective immunity against Babesia microti infection in mice.

No top-level findings curated for this source.

PMID:35512141

Babesia duncani as a Model Organism to Study the Development, Virulence, and Drug Susceptibility of Intraerythrocytic Parasites In Vitro and In Vivo.

No top-level findings curated for this source.

PMID:38169301

Tafenoquine-Atovaquone Combination Achieves Radical Cure and Confers Sterile Immunity in Experimental Models of Human Babesiosis.

No top-level findings curated for this source.

PMID:38814096

Tafenoquine for Relapsing Babesiosis: A Case Series.

No top-level findings curated for this source.

clinicaltrials:NCT06207370

A Double-blind Placebo-controlled Study to Assess the Safety and Efficacy of Oral Tafenoquine Plus Standard of Care Versus Placebo Plus Standard of Care in Patients Hospitalized for Babesiosis

No top-level findings curated for this source.

clinicaltrials:NCT07345988

Human Babesiosis in Metropolitan France: a Retrospective and Multicenter Descriptive Analysis.

No top-level findings curated for this source.

clinicaltrials:NCT01528449

Blood Donation Screening for Babesia Microti by Real-time Polymerase Chain Reaction (PCR) and by Indirect Flourescent Antibody (IFA) Assays

No top-level findings curated for this source.

url:https://www.cdc.gov/babesiosis/hcp/clinical-overview/index.html

Clinical Overview of Babesiosis | Babesiosis | CDC

No top-level findings curated for this source.

url:https://www.cdc.gov/babesiosis/hcp/clinical-care/index.html

Clinical Care of Babesiosis | Babesiosis | CDC

No top-level findings curated for this source.

Deep Research

1

Asta ▸

Asta Literature Retrieval: Pathophysiology and clinical mechanisms of Babesiosis. Core disease mechanisms, molecular and cellular pathways, invo...

Asta Scientific Corpus Retrieval 20 citations 2026-05-10T07:20:18.595164

Asta Literature Retrieval: Pathophysiology and clinical mechanisms of Babesiosis. Core disease mechanisms, molecular and cellular pathways, invo...

This report is retrieval-only and is generated directly from Asta results.

Papers retrieved: 20
Snippets retrieved: 20

Relevant Papers

[1] Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis

Authors: Ankit Puri, S. Bajpai, S. Meredith, L. Aravind, P. Krause et al.
Year: 2021
Venue: Frontiers in Microbiology
URL: https://www.semanticscholar.org/paper/2190fcd52b2b7e5a448fccea5b00ac8f1067461a
DOI: 10.3389/fmicb.2021.697669
PMID: 34539601
PMCID: 8446681
Citations: 40
Influential citations: 1
Summary: More than 100 Babesia spp. tick-borne parasites are known to infect mammalian and avian hosts. Babesia belong to Order Piroplasmid ranked in the Phylum Apicomplexa. Recent phylogenetic studies have revealed that of the three genera that constitute Piroplasmida, Babesia and Theileria are polyphyletic while Cytauxzoon is nested within a clade of Theileria. Several Babesia spp. and sub-types have been found to cause human disease. Babesia microti, the most common species that infects humans, is...
Evidence snippets:
Snippet 1 (score: 0.448) > The pathogenesis of Babesia spp. infections in humans is multifactorial, complex, and incompletely understood. In particular, molecular processes that underlie pathogenic mechanisms in human babesiosis have not been well researched. Pathogenesis studies are complicated by variation in pathogenic mechanisms for different Babesia spp. and variation in the immunologic status and pathophysiological response of hosts. Three clinical patterns of human babesiosis have been described: acute symptomatic disease which may be mild, moderate or severe, acute asymptomatic infection, and persistent infection (Vannier et al., 2008;Vannier and Krause, 2012). Acute asymptomatic infection is the most common clinical presentation. Asymptomatic infection occurs in about 20% of adults and is characterized by low parasitemia. Persistent infection follows acute symptomatic or asymptomatic infection and may last as long as 2 years (Krause et al., 1998(Krause et al., , 2007;;Raffalli and Wormser, 2016).

[2] Babesiosis: Appreciating the Pathophysiology and Diverse Sequela of the Infection

Authors: J. Ortíz, Paul W. Millhouse, Álvaro Morillo Cox, Leticia Campoverde, Arveen Kaur et al.
Year: 2020
Venue: Cureus
URL: https://www.semanticscholar.org/paper/a0ce001a737df3fac0d9bd8e77c62d805ec0706a
DOI: 10.7759/cureus.11085
PMID: 33224678
PMCID: 7678756
Citations: 11
Influential citations: 1
Summary: A better appreciation of all potential presentations and complications of Babesia microti infection will help clinicians manage this increasingly common zoonosis and reduce adverse effects.
Evidence snippets:
Snippet 1 (score: 0.410) > Babesiosis: Appreciating the Pathophysiology and Diverse Sequela of the Infection

[3] Canine Babesiosis and Therapy Options – A Review

Authors: Z. Malinovská
Year: 2024
Venue: Folia Veterinaria
URL: https://www.semanticscholar.org/paper/426a70cc0fab66bc533f2aa70665d10bfd6cb36e
DOI: 10.2478/fv-2024-0017
Citations: 5
Summary: The clinical manifestations of babesiosis may vary depending on the particular species and strains, and their specific virulence, but also depending on factors that determine the host’s response to infection, such as age, individual immune status, and the presence of concurrent infections or other diseases.
Evidence snippets:
Snippet 1 (score: 0.399) > Abstract Babesiosis is a disease caused by intraerythrocytic protozoal parasites, which occurs in animals and humans. In dogs, babesiosis can be caused by eight species of Babesia gene: i.e., B. canis, B. rossi, B. vogeli, B. coco, B. gibsoni, B. conradae, B., and B. negevi, which are bound to certain geographical areas. The disease has a focal nature and its transmission depends mainly on vectors, which are ticks of various species. Due to transstadial, and transovarial transmission, babesiosis is able to persist in natural foci in several generations of ticks, even without the presence of a susceptible host. Typical clinical signs associated with canine babesiosis are: fever, apathy, weakness, pale mucous membranes, icterus and hemoglobinuria. The disease can have an acute or peracute course, and subclinical and subacute infections have also been described. The clinical manifestations of babesiosis may vary depending on the particular species and strains, and their specific virulence, but also depending on factors that determine the host’s response to infection, such as age, individual immune status, and the presence of concurrent infections or other diseases. Medicines, from the group of antiprotozoans, a selected group of antibiotics, or their combinations are used for therapy. There are differences in the therapy of babesiosis depending on the Babesia species, the animal is often cured of the acute phase, but the parasite remains in the organism.

[4] Critical role of Babesia bovis spherical body protein 3 in ridge formation on infected red blood cells

Authors: Atefeh Fathi, Hassan Hakimi, M. Sakaguchi, Junya Yamagishi, S. Kawazu et al.
Year: 2024
Venue: PLOS Pathogens
URL: https://www.semanticscholar.org/paper/489ca411819deec14b41b0716cc0408f6bebcea8
DOI: 10.1371/journal.ppat.1012294
PMID: 39527619
PMCID: 11581398
Citations: 3
Summary: The vital role of SBP3 in ridge formation and its significance in the pathogenesis of cerebral babesiosis are revealed and light is shed on the molecular mechanism of ridge formation and the pathogenesis of B. bovis.
Evidence snippets:
Snippet 1 (score: 0.389) > Babesia is a tick-transmitted intraerythrocytic protozoan parasite infecting a large variety of domestic and wild animals, and sometimes humans [1]. Although more than 100 species of Babesia are known to infect mammalians, bovine Babesia parasites cause serious economic loss to cattle industries around the world [1,2]. Current control measures against bovine babesiosis are limited. Few drugs are available, and there are limitations in the usage of vaccines; moreover, resistance of the vector tick to acaricides has also become apparent recently [1][2][3]. Therefore, exploration of new control and treatment measures for the disease is urgently needed. > The two major species that cause bovine babesiosis are Babesia bovis and B. bigemina. The main clinical symptoms of bovine babesiosis are fever, anemia, and hemoglobinuria. While these symptoms are mainly caused by intravascular hemolysis and are common for B. bigemina infection, B. bovis infection adds an additional complication called cerebral babesiosis. Cytoadhesion of B. bovis-infected red blood cells (iRBCs) to brain microvascular endothelial cells leads to the sequestration of blood flow in the brain vascular system, causing cerebral symptoms and a high fatality rate in infected animals [1,4,5]. > Protrusions called "ridges" on the surface of iRBC are reported as the main sites for cytoadhesion to endothelial cells. Ridges are unique structures for B. bovis-iRBCs, and currently it is known that multiple proteins are exported from the parasites to the cytoplasm and surface of the iRBCs [6][7][8][9][10][11][12][13][14]. Although the function and export mechanisms are unknown for most of these proteins, it is thought that they contribute to enhancement of metabolite exchange, increase of RBC rigidity, and cytoadhesion to the host endothelial cells [4,7,15].

[5] LifeTime and improving European healthcare through cell-based interceptive medicine

Authors: N. Rajewsky, G. Almouzni, S. Gorski, S. Aerts, I. Amit et al.
Year: 2020
Venue: Nature
URL: https://www.semanticscholar.org/paper/d626a4acb560c1ef16ea394cb4dccf277882d119
DOI: 10.1038/s41586-020-2715-9
PMID: 32894860
PMCID: 7656507
Citations: 138
Influential citations: 2
Summary: The LifeTime initiative is an ambitious, multidisciplinary programme that aims to improve healthcare by tracking individual human cells during disease processes and responses to treatment in order to develop and implement cell-based interceptive medicine in Europe over the next decade.
Evidence snippets:
Snippet 1 (score: 0.368) > , a major challenge is a lack of understanding of the early events in disease onset to enable the development of disease-modifying therapies. The lack of access to longitudinal samples from patients necessitates the establishment of cohorts of patient-derived disease models to understand the cellular heterogeneity associated with disease. The discovery of pathways and biomarkers that will allow the stratification of patients on the basis of the cellular mechanisms that drive a disease will make it possible to design new clinical trials to reevaluate drugs that were previously tested without such stratification, and to broaden the drug target portfolio. > As seen during the coronavirus disease 2019 (COVID-19) pandemic, it is important to be able to understand infection mechanisms and the host response in order to rapidly identify the most likely effective treatment for an infection. At the same time, the continuous rise of antimicrobial resistance requires the discovery of new therapeutic strategies. A key medical challenge for infectious diseases is to understand the cellular response to infections and to develop precision, immune-based therapeutic strategies to combat infections. > Chronic inflammatory diseases impose a high burden owing to their long-term debilitating consequences, which result from the structural destruction of affected organs or tissues. Current therapies treat the symptoms but do not cure or fully control the chronic inflammatory pathophysiology. While different targeted therapies exist, they are expensive and their success is limited by high rates of non-response to treatment. Consequently, there is an urgent need to explore and understand how cellular heterogeneity contributes to the pathology of inflammatory diseases 61 and how this relates to the predicted course of disease and the response of a patient to one of the numerous available therapies. > Many cardiovascular and metabolic diseases lack effective therapies owing to a lack of knowledge of their underlying causes and the link between abnormal cardiac cell structure or function and pathophysiology. The identified medical priority is to understand the cellular and molecular mechanisms involved, in order to enable early diagnosis and the design of new mechanism-based therapies for precise clinical treatment. > The LifeTime disease roadmaps can be divided broadly into three phases 7 : first, immediate research into the identified medical challenges using established, scaled single-cell technologies, computational tools and disease models; second, the development of new technologies that are required

[6] Acid-base status in canine babesiosis caused by Babesia canis

Authors: M. Torti, J. Kuleš, V. Matijatko, M. Brkljačić, I. Kiš et al.
Year: 2020
Venue: Unknown venue
URL: https://www.semanticscholar.org/paper/2338148ace14ba6c54fe80dba8922cd464779dd6
DOI: 10.24099/vet.arhiv.1230
Citations: 4
Summary: The objective of this study was to determine the acid-base status, blood gases and electrolyte concentrations in naturally occurring canine babesiosis caused by B. canis, and to compare the results to those in healthy dogs.
Evidence snippets:
Snippet 1 (score: 0.365) > Canine babesiosis is a tick-borne disease caused by the hemoprotozoan parasites of the genus Babesia (TABOADA and MERCHANT, 1991). Babesia parasites are classified either as large or small Babesia (KUTTLER, 1988). The large Babesia include four different species, namely, Babesia canis (B. canis), B. rossi, B. vogeli, which were earlier classified as subspecies of B. canis (UILENBERG et al., 1989;SCHETTERS, 2005), and Babesia sp. (Coco) (BIRKENHEUER et al., 2004;LEHTINEN et al., 2008). Thus far, several small Babesia have been identified: B. gibsoni, B. conradae, and "Babesia vulpes", a name suggested depression, splenomegaly, and hyperkinetic pulse (LOBETTI, 1998;KOSTER et al., 2015). The prognosis of the uncomplicated form is good to excellent, if treated properly with antibabesial drugs (MATIJATKO et al., 2005). The complicated form of canine babesiosis is variable in its clinical manifestations, which in turn depend on the particular complications that develop in the course of the disease. Commonly reported complications of canine babesiosis are: acute renal failure, cerebral babesiosis, coagulopathy, icterus and hepatopathy, immune-mediated hemolytic anemia (IMHA), acute respiratory distress syndrome (ARDS), hemoconcentration, shock, and multiple organ dysfunction syndrome (MODS) (MATIJATKO et al., 2005;MATIJATKO et al., 2010;KOSTER et al., 2015). > The many and varied clinical manifestations of canine babesiosis cannot be linked to an organism that is restricted solely to erythrocytes.

[7] Bovine Babesiosis in Turkey: Impact, Current Gaps, and Opportunities for Intervention

Authors: S. Ozubek, R. Bastos, Heba F. Alzan, A. Inci, M. Aktas et al.
Year: 2020
Venue: Pathogens
URL: https://www.semanticscholar.org/paper/960a224aec3b5038c44ef0c2b6106d4bd6db434c
DOI: 10.3390/pathogens9121041
PMID: 33322637
PMCID: 7763958
Citations: 46
Influential citations: 3
Summary: Development of state-of-the-art research programs in bovine babesiosis to address current gaps in knowledge and implementation of long-term plans to control the disease will surely result in important economic, nutritional, and public health benefits for the country and the region.
Evidence snippets:
Snippet 1 (score: 0.364) > Two characteristics that define sensu stricto Babesia parasites are their ability to be transmitted transovarially by tick vectors and exclusively infect red blood cells (RBC) in their vertebrate host. These aspects are particularly important for B. bovis, B. bigemina, and B. divergens, the major causative agents of bovine babesiosis [6,7]. > Growth of asexual stages of Babesia parasites inside the vertebrate host RBC causes severe intravascular hemolytic anemia, which is a pathognomonic sign of the acute disease and highly debilitating for the host. Additionally, fever, prostration, abortion, and temporary infertility are also common clinical findings during acute infection. Hemoglobinuria is also usually present at the peak of the hemolytic crisis in B. bigemina or B. divergens infection and in late stages of the disease caused by B. bovis. In addition, residues and toxic metabolites released as a result of the infection and RBC destruction can negatively affect host organ systems [6][7][8]. Moreover, B. bovis has the unique ability to evade the cattle immune system by expressing proteins that facilitate cytoadhesion of infected RBC to capillaries, such as in the brain, causing neurological symptoms and generalized organ failure, a feature that results in increased virulence. Altogether, these pathological mechanisms frequently lead to rapid death of cattle during the acute stage of the disease, especially when affecting adult naïve animals. > Upon infection, the immune system of the host responds differentially, depending on the age of the animals. While young animals, less than seven months old, are frequently able to control severe acute babesiosis and can survive re-exposures to the parasites, older than one-year-old animals often succumb rapidly to infection. Features associated with resistance in young animals include early and strong activation of the innate and adaptive immune effectors. Briefly, the parasite expresses molecules able to bind pathogen associated molecular patterns (PAMPs) receptors expressed on the surface of dendritic cells (DC), macrophages, neutrophils, and monocytes, especially TLR9 [9,10], and an immune response is initiated.

[8] LC-MS/MS analysis of the dog serum phosphoproteome reveals novel and conserved phosphorylation sites: Phosphoprotein patterns in babesiosis caused by Babesia canis, a case study

Authors: A. Galán, A. Horvatić, J. Kuleš, Petra Bilić, Jelena Gotić et al.
Year: 2018
Venue: PLoS ONE
URL: https://www.semanticscholar.org/paper/04c4f2552dde9f329a0d7046a9ebb394ece93c90
DOI: 10.1371/journal.pone.0207245
PMID: 30485286
PMCID: 6261647
Citations: 14
Summary: The alterations of phosphorylated proteins observed in canine babesiosis caused by Babesia canis suggest new insights into the largely neglected role of extracellular protein phosphorylation in health and disease, encouraging urgent further research on this area.
Evidence snippets:
Snippet 1 (score: 0.351) > [33,34]. Cytokines have also been suggested as markers associated to the occurrence of complications in canine babesiosis elicited by several babesial species [35,36]. > Interestingly, a polymorphic membrane phosphoprotein (BrEMA1) has been described on the plasma membrane of Babesia Rossi-infected erythrocytes that is suspected to constitute a major virulence factor [37]. Babesia canis-caused infection could potentially contribute with the parasite's phosphoproteins to the canine serum proteome, acting as biomarkers of the infection. Some other phosphoproteins such as Trypanosoma cruzi's calcineurin B, a phosphatase, are involved in host cell invasion [38] and ecto-kinases have been found to be secreted by Leishmania major [39]. Moreover, phosphorylation of extracellular proteins can operate in signaling pathways responsible for cellular adaptation [5,6], making serum an untapped source of phosphoproteins suitable for better understanding disease pathophysiology and discovery of disease biomarkers [28]. > The present study shows an approach to characterize qualitatively individual serum samples and quantitatively pools containing the same 10 control samples and 10 samples from dogs suffering from babesiosis before the onset of organic dysfunction [40]. In order to test alterations in serum phosphoproteins as potential markers for babesiosis, we have used state-ofthe-art phosphopeptide enrichment procedures and optimized LC-MS/MS protocols to maximize the detection of phosphorylation sites. Combined qualitative and quantitative analyses offer novel data on the alteration of phosphoprotein levels in babesiosis, a hemolytic infection closely related to malaria and sepsis and the concomitant acute systemic inflammation. Variations observed could represent candidate biomarkers for the early detection of babesiosis in dogs and show potential usefulness in clinical applications.

[9] Differential Regulation of Interferon Signaling Pathways in CD4+ T Cells of the Low Type-2 Obesity-Associated Asthma Phenotype

Authors: Fahd Alhamdan, L. Marsh, F. Pedersen, B. A. Alhamwe, C. Thölken et al.
Year: 2021
Venue: International Journal of Molecular Sciences
URL: https://www.semanticscholar.org/paper/64e368bc44d989aa672152b1812fa77c44e3189c
DOI: 10.3390/ijms221810144
PMID: 34576307
PMCID: 8469911
Citations: 23
Summary: The specific activation of interferon (IFN)-stimulated genes associated with IFN-related signaling and viral infection pathways might provide a novel view of the molecular mechanisms associated with the development of the low type-2 obesity-associated asthma phenotype, which is a step ahead in theDevelopment of new stratified therapeutic approaches.
Evidence snippets:
Snippet 1 (score: 0.343) > Over the last decades, non-communicable diseases (NCDs) have become the major cause of death worldwide, especially after the development of effective anti-infectious measures of prevention (vaccines) and treatment (antibiotics) [1][2][3]. Moreover, they represent a huge burden on the healthcare system and economic situation [4,5]. Prevalence and incidence of NCDs are still further increasing along with ongoing urbanization, industrialization, and globalization of unhealthy diet and lifestyles [6,7]. According to the World Health Organization (WHO), the rapid increase in the NCDs is mainly driven by various risk factors including tobacco, harmful use of alcohol, and obesity [8]. Furthermore, different NCDs and their major risk factors seem to have substantially overlapping underlying mechanisms, often involving immunometabolic alterations [9,10]. Combinations of certain NCDs and associated risk factors can create separate specific disease entities, classified as a clinical subtype or phenotype [11]. > Obesity is a key risk factor underlying a variety of major NCDs, including asthma [10,12]. The comorbidity of obesity and asthma is referred to as obesity-associated asthma [13,14]. Various associated clinical characteristics of obesity and asthma have been described. The major obesity-associated asthma phenotype is characterized as "late-onset, severe and difficult to treat, type-2 low inflammation disease and presenting mostly in women" [15][16][17]. While these detailed clinical characteristics strictly define this particular phenotype of asthma, the specific underlying cellular and molecular mechanisms of this phenotype are still only poorly understood. > Gene expression alterations, especially in cells critically involved in disease development, represent a major molecular contributor to the pathophysiology of chronic inflammatory diseases such as asthma. Subsets of CD4 + T cells, such as Th1, Th2, and Th17 have been shown to differentially contribute to the initiation and perpetuation of specific asthma phenotypes [18,19]. Certain biological pathways and cellular processes play an essential role in the polarization of the CD4 + T cells subtypes [20].

[10] The evolving burden of asthma and contemporary advances in management: Implications for clinical practice in Southern Africa

Authors: A. Kiboneka
Year: 2020
Venue: Unknown venue
URL: https://www.semanticscholar.org/paper/0ba536bc7dbea898dcaabe247c92c7897c7e059c
DOI: 10.30574/wjarr.2020.8.3.0315
Citations: 1
Summary: The development of novel asthma phenotyping & endo typing plus better classification of patients using machine learning and big data have markedly improved asthma treatment outcomes in both children and Adults, and several research groups have developed cluster analyses of phenotypes in severe asthma.
Evidence snippets:
Snippet 1 (score: 0.343) > Research Program (SARP) I and II cohorts to study mechanisms differentiating severe from non-severe asthma. SARP investigators characterized severe asthma as a heterogeneous syndrome with diverse molecular, biochemical, and cellular inflammatory features and structure-function abnormalities. > Adults and children with severe asthma were further categorized by unbiased statistical methods into clusters based on distinguishing clinical features. These studies have not been done in Sub-Sahara Africa. Research performed over the past one to two decades has sought to better understand the heterogeneous clinical nature of asthma. Whereas older attempts at phenotyping asthma emphasized the duality of allergic vs. non-allergic asthma, more recent non-biased analyses have attempted to cluster patients by a multitude of possible features, including age of onset, atopy, severity of airways obstruction, and requirement for medication. Examples of these phenotypes include early-onset mild allergic asthma, later-onset asthma associated with obesity, and severe non-atopic asthma with frequent exacerbations. The elucidation of asthma phenotypes has been further refined by including information regarding pathophysiologic mechanisms present in different groups. These groups, called endo-types, include examples such as aspirin-exacerbated respiratory disease and allergic bronchopulmonary mycosis. > A phenotype covers the clinically relevant properties of the disease, but does not show the direct relationship to disease etiology and pathophysiology. Different patho-genetic mechanisms might cause similar asthma symptoms and might be operant in a certain phenotype. These putative mechanisms are addressed by the term 'endotype'. > Classification of asthma based on endo-types provides advantages for epidemiological, genetic, and drug-related studies. A successful definition of endo-types should link key pathogenic mechanisms with the asthma phenotype. Thus, the identification of corresponding molecular biomarkers for individual pathogenic-mechanism underlying phenotypes or subgroups within a phenotype is important. > The term asthma encompasses a disease spectrum with mild to very severe disease phenotypes whose traditional common characteristic is reversible airflow limitation. Unlike milder disease, severe asthma is poorly controlled by the current standard of care.

[11] Solving the Evidence Interpretability Crisis in Health Technology Assessment: A Role for Mechanistic Models?

Authors: E. Courcelles, J. Boissel, J. Massol, I. Klingmann, R. Kahoul et al.
Year: 2022
Venue: Frontiers in Medical Technology
URL: https://www.semanticscholar.org/paper/877d5b1b75599745f704a9c8371f74601ff17e2f
DOI: 10.3389/fmedt.2022.810315
PMID: 35281671
PMCID: 8907708
Citations: 6
Summary: Light is shed on different stakeholder's contributions and needs in the appraisal phase and how mechanistic modeling strategies and reporting can contribute to this effort to implement mechanistic models central in the evidence generation, synthesis, and appraisal of HTA so that the totality of mechanistic and clinical evidence can be leveraged by all relevant stakeholders.
Evidence snippets:
Snippet 1 (score: 0.337) > A second limitation in HTA is the fact that currently population (and sometimes stratified) medicine is pursued during clinical Uncertainty not completely addressed in competent authority assessment report Example use of MIDD relevant to address uncertainty potentially also during HTA What is the optimal dosage in the clinical context? > Physiologically based pharmacokinetic models can investigate dosing-regimens relevant for regulatory review and product labels (9) and can also mimic real-life adherence to prescribed treatment regimens (see also below) or pharmacology-relevant characteristics of special populations as well as drug-drug interactions. > What is the duration of the effectiveness, especially with chronic use of a treatment? > Mechanistic models can predict the long-term disease progression by extrapolation of shorter-term findings under the constraints of how the components of the system function (and these constraints convey biological plausibility by design). An example is the use of a mechanism-based disease progression model for comparison of long-term effects of pioglitazone, metformin, and gliclazide on disease processes underlying Type 2 Diabetes Mellitus (10). Another example is prediction of long-term outcomes by short-term marker data as demonstrated by a semi-mechanistic approach in context of osteoporosis treatment (11). > What is the efficacy for relevant clinical outcomes? > Mechanistic models combined with pharmacometric approaches can translate findings for one outcome to a range of other outcomes. An example of survival modeling on the back of a mechanistic description is the modeling framework for CD19-Specific CAR-T cell immunotherapy using a quantitative systems pharmacology model (12). > What is the size of the clinical effect dependent on patient characteristics and extrinsic factors? > Data-driven modeling techniques can capture correlation within clinical data. Describing the clinical effect of a drug can also be based on mechanistic considerations. Such models either (a) link disease phenotypes to increasingly granular mathematical representations of pathophysiologic processes (top-down approach) or (b) derive functional, computable cellular networks from the molecular building blocks of genes and proteins to elucidate the impact of pathologic or therapeutic alterations on network operating states and hence clinical phenotype (bottom-up) [

[12] Changes in Serum Proteomic Profiles at Different Stages of Pregnancy Toxemia in Goats

Authors: M. Uzti̇mür, C. N. Ünal, Gurler Akpinar
Year: 2025
Venue: Journal of Veterinary Internal Medicine
URL: https://www.semanticscholar.org/paper/4b9c488b5dbd65d7b26fd2ad9aed70e8c4b59942
DOI: 10.1111/jvim.70139
PMID: 40492724
PMCID: 12150350
Summary: Understanding the serum proteome profiles of goats with pregnancy toxemia might help identify the proteomes and pathways responsible for the development of this disease and improve diagnosis and treatment.
Evidence snippets:
Snippet 1 (score: 0.336) > The pathophysiology and progression of this disease are not fully understood. > Traditional biomedical research has focused on the analysis of single genes, proteins, metabolites, or metabolic pathways in diseases. This molecular reductionist approach is based on the assumption that identifying genetic variations and molecular components will lead to new treatments for diseases [13][14][15][16]. However, many diseases are complex and multifactorial, and in order to determine the phenotype of such diseases, it is necessary to understand the changes that occur in more than one gene, pathway, protein, or metabolite at the cellular, tissue, and organismal levels [17][18][19]. Therefore, in recent years, proteomics, as one field of multi-omics technologies, has helped in evaluating the complex pathogenetic mechanisms of different diseases from a broad perspective and has made substantial contributions [20,21]. In veterinary medicine, proteomic analysis of metabolic diseases such as ketosis [16], hypocalcemia [22], and fatty liver [23] in dairy cows has contributed valuable insights for the definition of new pathophysiological pathways and new diagnosis and treatment protocols for these diseases. The proteomic approach can contribute importantly to a broad and detailed understanding of the changes that occur at the organismal level associated with the increase in BHBA concentration in goats with pregnancy toxemia. Our aim was to evaluate the serum protein profiles of goats with SPT or CPT using proteomic techniques to determine the proteomic profiles of these animals and to identify the relevant pathophysiological mechanisms.

[13] 18O-assisted dynamic metabolomics for individualized diagnostics and treatment of human diseases

Authors: E. Nemutlu, Song Zhang, N. Juranic, A. Terzic, S. Macura et al.
Year: 2012
Venue: Croatian Medical Journal
URL: https://www.semanticscholar.org/paper/880f053c7f060db4b990e447d0a22c4b69372ddb
DOI: 10.3325/cmj.2012.53.529
PMID: 23275318
PMCID: 3541579
Citations: 28
Summary: The potential use of dynamic phosphometabolomic platform for disease diagnostics currently under development at Mayo Clinic is described and discussed briefly.
Evidence snippets:
Snippet 1 (score: 0.336) > Living cells represent an integrated and interacting network of genes, transcripts, proteins, small signaling molecules, and metabolites that define cellular phenotype and function. Traditionally the focus of biomedical research was on individual genes, single protein targets, single metabolites, and metabolic or signaling pathways. This "molecular reductionist" paradigm was based on the assumption that identifying genetic variations and molecular components would lead to discovery of cures for human diseases. However, most of diseases are complex and multi-factorial and the disease phenotype is determined by the alterations of multiple genes, pathways, proteins and metabolites (at cellular, tissue, and organismal levels). Therefore, an integrated "omics" approach is more viable direction for uncovering alterations in metabolic networks, disease mechanisms, and mechanisms of drug effects. > Recent advent of large-scale metabolomics and fluxomic (metabolite dynamics and metabolic flux analysis) completed the "omics revolution" (Figure 1), where genomics, transcriptomics, proteomics, metabolomics, and fluxomics all together complement phenotype determination of living organism. Such integrated "omics" cascades provide a framework for advances in system and network biology, integrative physiology, and system medicine as well as system pharmacology and regenerative medicine. Noteworthy is the "reverse omic" approach or "metabolomicsinformed pharmacogenomics, " where discovery of specific metabolite changes have led to discovery of genetic alterations (2). Therefore, bringing new "omics" technologies to clinical practice will improve disease diagnostics and treatment by targeting drugs and procedures for each unique transcriptomic and metabolomic profiles.

[14] Chemotherapy and Mechanisms of Resistance in Breast Cancer

Authors: A. Oliveira, R. E. Santos, F. F. O. Rodrigues
Year: 2012
Venue: Unknown venue
URL: https://www.semanticscholar.org/paper/502a86d8bcd7208be6f539fcceba631f82f25a7d
DOI: 10.5772/24629
Summary: The addition of adjuvant polychemotherapy in advanced breast cancer showed gain by controlling survival of micrometastases in patients with lymph nodes affected by cancer or not.
Evidence snippets:
Snippet 1 (score: 0.334) > The main reasons responsible for treatment failure in cancer patients are the mechanisms of drug resistance and emergence of disseminated disease (Terek et al, 2003). We identified two types of resistance most relevant to BC: primary resistance, which corresponds to the clinical situation where the patient showed no response to therapy, and secondary or acquired resistance in which, initially, there is an observed response and a subsequent failure of the treatment regimen (Kroger et al, 1999). Several mechanisms may cause the phenotype of multidrug resistance to chemotherapy drugs and are well characterized in in vitro experiments, including alterations in systemic pharmacology (pharmacokinetics and metabolism), extracellular mechanisms (tumor environment, multicellular drug resistance), and cellular mechanisms (cellular pharmacology, activation and inactivation of drugs, modification of specific targets and regulatory pathways of apoptosis) (Leonessa et al, 2003, Riddick et al, 2005. Identification of factors that affect cell metabolism, which are related to drug resistance, will enable the identification of which patients are at particular risk of treatment failure. Among the biochemical and molecular mechanisms of drug resistance, we stress: changes in the activity of topoisomerase II, alterations in the DNA repair mechanism, overexpression of P-glycoprotein; high intracellular concentrations of enzymes purification of cellular metabolism -among them enzymes the family of glutathione S-transferases (GSTs) and changes in the mechanisms of signaling via c-Jun N-terminal kinase 1 (JNK1) -and "apoptosis signal-regulating kinase (ASK1) required for activation of the" mitogenactivated protein (MAP kinases) in apoptosis and cellular restoration. These pathways are also mediated by proteins encoded by genes of GSTs (O'Brien, Tew, 1996;Burg, Mulder, 2002, L'Ecuyer et al, 2004). Different response rates to particular chemotherapy regimens, as observed in patient groups with the same biological characteristics and stage, suggest the existence of different mechanisms of drug resistance, probably induced by genetic alterations (Hayes, Pulford, 1995;O'Brien , Tew, 1996;Pakunlu et al, 2003). Among the mechanisms of purification of cellular metabolism involved in the

[15] Organoids in gastrointestinal diseases: from bench to clinic

Authors: Qinying Wang, Fanying Guo, Qinyuan Zhang, Tingting Hu, Yutao Jin et al.
Year: 2024
Venue: MedComm
URL: https://www.semanticscholar.org/paper/9b8880d8b9d45670da950197d7e353794f51d09e
DOI: 10.1002/mco2.574
PMID: 38948115
PMCID: 11214594
Citations: 12
Summary: A comprehensive and systematical depiction of organoids models is drawn, providing a novel insight into the utilization of organoids models from bench to clinic and clinical adhibition.
Evidence snippets:
Snippet 1 (score: 0.333) > Organoids models offer a robust platform for investigating the potential mechanisms of GI diseases and evaluating potential therapeutic interventions.By culturing organoids derived from patients' tissues or stem cells, researchers can delve into disease-specific cellular and molecular pathways, encompassing aberrant cell signaling, perturbed immune responses, and dysfunctional metabolic processes.These disease-specific phenotypes enable the study of disease progression, screening of prospective therapeutics, as well as identification of novel drug targets and mechanisms of action for GI diseases in a clinically relevant context.

[16] Immunization of Cattle With Recombinant Structural Ectodomains I and II of Babesia bovis Apical Membrane Antigen 1 [BbAMA-1(I/II)] Induces Strong Th1 Immune Response

Authors: Amarin Rittipornlertrak, Boondarika Nambooppha, Anucha Muenthaisong, Nisachon Apinda, Pongpisid Koonyosying et al.
Year: 2022
Venue: Frontiers in Veterinary Science
URL: https://www.semanticscholar.org/paper/a1ade815ad596ebd9218b29824de2f1239fdfb8e
DOI: 10.3389/fvets.2022.917389
PMID: 35812841
PMCID: 9260583
Citations: 3
Summary: The results indicate that immunization of cattle with BbAMA-1(I/II) could induce strong Th1 cell responses and is recognized as a potential candidate vaccine against B. bovis infection.
Evidence snippets:
Snippet 1 (score: 0.332) > Most apicomplexans are obligate intracellular parasites. Babesia, an apicomplexan parasite, is a tick-transmitted hemoprotozooan. The most economically relevant bovine babesias are Babesia bovis (B. bovis) and Babesia bigemina (B. bigemina). Presently, a large number of cattle are at risk of exposure to bovine babesiosis. Bovine babesiosis is recognized as a global disease that has been the cause of significant economic losses to the livestock industry (1). Climate change is one of the factors that can influence the control of bovine babesiosis (2). Pathologically, a cyclical asexual replication of Babesia in red blood cells (RBC) that is associated with an excessive immune response has been known to lead to the development of several clinical manifestations. In general, bovine babesiosis can be treated with chemotherapy (1). However, the emergence of drug resistance in B. bovis has been recently documented (3). Although live attenuated vaccines are available in some endemic countries, the applications for wide use of these vaccines are limited for a number of reasons. At present, there are no safe and effective vaccines that protect cattle against the virulent pathogens (4). Thus, novel vaccines are increasingly desirable and urgently needed to control this disease (2). > The host-parasite interaction is of major importance for parasite survival. Without host cells, which supply environment and nutrition, the parasitic protozoa cannot grow and survive. The formation of a moving junction (MJ) between the parasite and host cell membranes is an important conserved mechanism that facilitates the parasitic invasion into host cells during the asexual growth cycle of apicomplexan parasites (5). The apical membrane antigen 1 (AMA-1) has been well characterized and reported to be involved in MJ formation in coordination with the rhoptry neck 2 (RON2) protein in Toxoplasma and Plasmodium (6,7). It is likely directly responsible for reorientation and initiates the junctional contact. AMA-1, a microneme protein (MIC), is a type I integral membrane protein that is composed of three distinct structures (8).

[17] Genomic Study of Babesia bovis Infection Level and Its Association With Tick Count in Hereford and Braford Cattle

Authors: L. Cavani, C. U. Braz, R. Giglioti, C. Okino, C. C. Gulias-Gomes et al.
Year: 2020
Venue: Frontiers in Immunology
URL: https://www.semanticscholar.org/paper/427b382a8aaac279e7a7739ebba41e6bd62052c0
DOI: 10.3389/fimmu.2020.01905
PMID: 33013839
PMCID: 7493685
Citations: 10
Summary: Although the genetic correlation between IB and TC was weak, some candidate genes for IB were also reported in tick infestation studies, and they were also involved in biological resistance processes, suggesting that genomic predictions could be used as a tool to improve genetics for IB, especially if a larger training population is developed.
Evidence snippets:
Snippet 1 (score: 0.329) > Figure 2 shows the Manhattan plot with the percentages of additive genetic variance explained by each SNP for the IB trait. The top 10 SNPs (Table 5) explained 5.05% of IB additive genetic variance and identified 42 candidate genes involved in biological mechanisms that may underlie B. bovis resistance in cattle. Defense against parasites is mediated by sequential and coordinated immune responses called innate and adaptative (65), and several of the candidate genes participate in immune system pathways (ATP8A1, LCP1, LRCH1, QSOX1, FGF2, DSC1, DSC3, FGFR2, and CEBPG), which include adaptive and innate immune systems, and cytokine signaling pathways, indicating that genetic variations in these genes can alter the immune response and consequently, influence susceptibility and outcome of babesiosis in cattle. An essential aspect of B. bovis infection is that young calves have strong innate immunity, which lasts until about 6 months of age (66). Animals that survive infection with B. bovis become persistently infected and resistant to the clinical form of the disease, a phenomenon known as concomitant immunity (67). Adaptative immunity mechanisms are responsible for the absence of clinical signs in persistently infected animals. LCP1 is a protein of the plastin family. This family is composed of actin-binding proteins that are conserved evolutionarily and expressed in different types of plants and animals (68). In mammals, three isoforms have been identified: T, I, and L-plastin. This latter group includes LCP1 that is expressed in hematopoietic cell lines, with essential functions in the activation of macrophages (69), lymphocytes, and granulocytes (70). According to Brown (71), the immune response against babesiosis depends on the activation of CD4+ T lymphocytes in the development of acquired protein antigen-specific responses. CD4+ T cells are essential for coordinating high-affinity IgG production and activating macrophages through the production of IFN-È. > LRCH1 also encodes proteins that influence the migration of CD4+ T cells (72).

[18] Targeting Hepatic Stellate Cells for the Prevention and Treatment of Liver Cirrhosis and Hepatocellular Carcinoma: Strategies and Clinical Translation

Authors: Hao Xiong, Jinsheng Guo
Year: 2025
Venue: Pharmaceuticals
URL: https://www.semanticscholar.org/paper/76e92127053136900f7e3f10e2c9278251ced5d2
DOI: 10.3390/ph18040507
PMID: 40283943
PMCID: 12030350
Citations: 10
Summary: HSC-targeted approaches using specific surface markers and receptors may enable the selective delivery of drugs, oligonucleotides, and therapeutic peptides that exert optimized anti-fibrotic and anti-HCC effects.
Evidence snippets:
Snippet 1 (score: 0.326) > Significant progress has been made in elucidating the cellular and molecular mechanisms of liver fibrosis; however, only a few findings have been successfully translated into clinical applications. Firstly, the high cost of drug development and target validation necessitates prolonged timelines and substantial financial investment. Secondly, as regulatory requirements become more stringent, there is an increasing demand for drugs with well-defined clinical efficacy and safety profiles. Moreover, the efficacy observed in animal models often fails to fully translate to clinical settings due to differences in pharmacokinetics, extracellular matrix (ECM) cross-linking, and disease pathophysiology. Despite advancements in anti-fibrotic drug development, accurately identifying ideal noninvasive biomarkers for fibrotic activity and establishing consensus on optimal clinical endpoints remain significant challenges [113,114]. > Currently, addressing the underlying cause remains the only proven strategy to halt or reverse liver fibrosis progression, while the development of effective anti-fibrotic therapies continues to pose a major challenge in liver disease management. Over the past few decades, substantial progress has been made in elucidating the cellular and molecular mechanisms underlying liver fibrosis. Liver fibrosis is a complex pathological change involving multiple cells, factors, and pathways, and the study of the cellular and molecular mechanisms of its occurrence and development provides an important theoretical basis and therapeutic target for clinical drug development. It is anticipated that improved animal models and well-designed clinical trials will facilitate the successful translation of anti-fibrotic research into effective clinical treatments in the near future.

[19] New therapeutic targets in rare genetic skeletal diseases

Authors: M. Briggs, Peter A. Bell, M. Wright, K. A. Pirog
Year: 2015
Venue: Expert Opinion on Orphan Drugs
URL: https://www.semanticscholar.org/paper/1363107f71ae6d2d60abca471cddf3da5d13644b
DOI: 10.1517/21678707.2015.1083853
PMID: 26635999
PMCID: 4643203
Citations: 38
Influential citations: 1
Summary: An overview of disease mechanisms that are shared amongst groups of different GSDs and potential therapeutic approaches that are under investigation are described to generate critical mass for the identification and validation of novel therapeutic targets and biomarkers.
Evidence snippets:
Snippet 1 (score: 0.325) > proteins of the cartilage ECM such as type II collagen [50]. However, emerging knowledge suggests that the primary genetic defect may be less important than the cells' response to the expression of the mutant gene product [107]. Moreover, the largely overlooked response of a cell (i.e. chondrocyte) to the abnormal extracellular environment is also important for disease progression as illustrated by several GSDs discussed in this review. > It is important that 'omics'-based approaches and technologies are systematically applied to the study of rare GSDs so that definitive reference profiles and disease signatures are generated for each phenotype. These can then be used in a Systems Biology approach to identify both common and dissimilar pathological signatures and disease mechanisms. This approach is entirely dependent upon relevant in vitro and in vivo models (and also novel 'disease-mechanism phenocopies' [107]) for testing new diagnostic and prognostic tools and for determining the molecular mechanisms that underpin the pathophysiology so that effective therapeutic treatments can be developed and validated. This approach will eventually lead to personalized treatments and care strategies centred on shared disease mechanisms with the use of relevant biomarkers to monitor the efficacy of treatment and disease progression. > It is vital that all relevant stakeholders are involved from the outset in defining the appropriate outcomes of any potential therapeutic regime. The perceptions of a successful therapy can differ widely between the clinical academic community and the relevant patient-support groups and it is vital that there is engagement on all these issues. > In summary, the identification of causative genes and mutations for GSDs over the last 20 years, coupled with the generation and in-depth analysis of a plethora of relevant cell and mouse models, has derived new knowledge on disease mechanisms and suggested potential therapeutic targets. The fast-evolving hypothesis that clinically disparate diseases can share common disease mechanisms is a powerful concept that will generate critical mass for the identification and validation of novel therapeutic targets and biomarkers.

[20] Future research trends in understanding the mechanisms underlying allergic diseases for improved patient care

Authors: H. Breiteneder, Z. Diamant, T. Eiwegger, W. Fokkens, C. Traidl‐Hoffmann et al.
Year: 2019
Venue: Allergy
URL: https://www.semanticscholar.org/paper/e19b0755c4f4903f68377333676edebf9bd73c89
DOI: 10.1111/all.13851
PMID: 31056763
PMCID: 6973012
Citations: 90
Influential citations: 3
Summary: Recent developments in research and patient care and future trends in the discipline are reviewed and topics on food allergy, biologics, small molecules, and novel therapeutic concepts in allergen‐specific immunotherapy for airway disease are highlighted.
Evidence snippets:
Snippet 1 (score: 0.325) > The past decades have witnessed extensive progress in unraveling cellular and molecular mechanisms of immune regulation in asthma, allergic diseases, organ transplantation, autoimmune diseases, tumor biology, and chronic infections. 1,2 Consequently, a better understanding of the functions, the reciprocal regulation, and the counterbalance of subsets of immune and inflammatory cells but also structural cells-for example, epithelial and vascular cells, airway smooth muscle cells, neuroendocrine system-that interact via various intercellular messengers will indicate avenues for immune interventions and novel treatment modalities of allergic diseases and immunological disorders. It is generally expected that drug development in the next decades will show a significant shift from chemicals to biologicals. > After more than 20 years without any breakthrough drug becoming available for patients, several disciplines including allergology are now experiencing extraordinary times with the recent licensing of several major biological drugs and novel allergen-specific immunotherapy (AIT) vaccines. Several biological modifiers of the immune response targeting intracellular messengers or their receptors have been developed to date. [3][4][5][6][7][8] In addition, a number of promising small molecule drugs and vaccines are in the development pipeline. [9][10][11] This new era is now calling for the development of biomarkers and phenoand endotyping of diseases for customized patient care, which is termed stratified medicine, precision medicine, or personalized medicine. 4 Distinguishing phenotypes of a complex disease covers the observable clinically relevant properties of the disease but does not show a direct relationship to disease etiology and pathophysiology. In a complex condition, such as asthma, different pathogenetic mechanisms can induce similar clinical manifestations; however, they may require different treatment approaches. 12,13 These pathophysiological mechanisms underlying disease subgroups are addressed by the term "endotype." [12][13][14] Classification of complex diseases based on the concept of endotypes provides advantages for epidemiological, genetic, and drug-related studies. Accurate endotyping by using reliable biomarkers reflects the natural history of the disease and aims to predict the response to (targeted) treatments. 15 Recent studies have focused on better understanding

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References & Deep Research

References

Deep Research

Asta Literature Retrieval: Pathophysiology and clinical mechanisms of Babesiosis. Core disease mechanisms, molecular and cellular pathways, invo...

Relevant Papers

[1] Babesia microti: Pathogen Genomics, Genetic Variability, Immunodominant Antigens, and Pathogenesis

[2] Babesiosis: Appreciating the Pathophysiology and Diverse Sequela of the Infection

[3] Canine Babesiosis and Therapy Options – A Review

[4] Critical role of Babesia bovis spherical body protein 3 in ridge formation on infected red blood cells

[5] LifeTime and improving European healthcare through cell-based interceptive medicine

[6] Acid-base status in canine babesiosis caused by Babesia canis

[7] Bovine Babesiosis in Turkey: Impact, Current Gaps, and Opportunities for Intervention

[8] LC-MS/MS analysis of the dog serum phosphoproteome reveals novel and conserved phosphorylation sites: Phosphoprotein patterns in babesiosis caused by Babesia canis, a case study

[9] Differential Regulation of Interferon Signaling Pathways in CD4+ T Cells of the Low Type-2 Obesity-Associated Asthma Phenotype

[10] The evolving burden of asthma and contemporary advances in management: Implications for clinical practice in Southern Africa

[11] Solving the Evidence Interpretability Crisis in Health Technology Assessment: A Role for Mechanistic Models?

[12] Changes in Serum Proteomic Profiles at Different Stages of Pregnancy Toxemia in Goats

[13] 18O-assisted dynamic metabolomics for individualized diagnostics and treatment of human diseases

[14] Chemotherapy and Mechanisms of Resistance in Breast Cancer

[15] Organoids in gastrointestinal diseases: from bench to clinic

[16] Immunization of Cattle With Recombinant Structural Ectodomains I and II of Babesia bovis Apical Membrane Antigen 1 [BbAMA-1(I/II)] Induces Strong Th1 Immune Response

[17] Genomic Study of Babesia bovis Infection Level and Its Association With Tick Count in Hereford and Braford Cattle

[18] Targeting Hepatic Stellate Cells for the Prevention and Treatment of Liver Cirrhosis and Hepatocellular Carcinoma: Strategies and Clinical Translation

[19] New therapeutic targets in rare genetic skeletal diseases

[20] Future research trends in understanding the mechanisms underlying allergic diseases for improved patient care

Notes