Brucellosis

Infectious Disease MONDO:0005683 Pathograph 46 Show in embeddings browser zoonotic bacterial infection primary bacterial infectious disease

Brucellosis is a zoonotic bacterial infection caused by Brucella species, typically acquired through exposure to infected animals, contaminated animal products, or unpasteurized dairy products. Clinical illness often presents as a systemic febrile syndrome and may relapse or involve focal complications.

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1
Definitions
18
Pathophys.
21
Phenotypes
3
Gaps
46
Pathograph
4
Medical Actions
3
Datasets
1
Deep Research
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Classifications

Harrison's Part
INFECTIOUS DISEASES
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Definitions

1
Clinical syndrome definition
Brucellosis is a zoonotic Brucella infection with non-specific systemic symptoms such as fever, fatigue, and joint pain, and can cause focal complications including endocarditis and arthritis.
CASE_DEFINITION Human brucellosis clinical syndrome
Show evidence (2 references)
PMID:23236528 SUPPORT Human Clinical
"Brucellosis is a bacterial disease transmitted to humans by consumption of infected, unpasteurised animal milk or through direct contact with infected animals"
Peer-reviewed systematic review framing brucellosis as a zoonotic bacterial infection acquired from animals and animal products (replaces a preprint citation).
DOI:10.1097/QCO.0000000000001045 SUPPORT Other
"Given the global prevalence and potential complications of brucellosis, understanding recent advancements in diagnostic techniques and treatment strategies is crucial for clinicians."
Supports the global and complicated clinical scope of brucellosis.
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Discussions and Knowledge Gaps

3
What is the optimal antibiotic regimen and duration for adult, focal, and complicated human brucellosis (spondylitis, sacroiliitis, endocarditis, neurobrucellosis), given that the strongest comparative-efficacy ranking (doxycycline + gentamicin) derives from a network meta-analysis restricted to children and adolescents that explicitly excluded focal disease and pregnancy?
KNOWLEDGE GAP OPEN gap_brucellosis_regimen_focal_adult
Attached to
pathophysiology#Persistent multisystem infection
The 2024 network meta-analysis that ranked doxycycline + gentamicin highest for efficacy restricted inclusion to trials of children and adolescents and excluded spondylitis, endocarditis, neurobrucellosis, and pregnancy, so its ranking cannot be applied directly to the focal and complicated adult disease that drives most brucellosis morbidity. Regimen choice and duration for these presentations still rest on heterogeneous observational data, and improved treatment regimens remain an explicitly stated open challenge in the field.
Proposed experiments
Multicenter randomized trial of doxycycline-gentamicin versus triple therapy in adult focal/complicated brucellosis
randomized controlled trial Relation: this experiment is of type this experiment type This experiment is of type randomized controlled trial.
exp_brucellosis_adult_focal_rct
Enroll adults with spondylitis, sacroiliitis, endocarditis, or neurobrucellosis and randomize to doxycycline + gentamicin versus a doxycycline-rifampicin-based triple regimen, with protocolized durations and long-term follow-up, using microbiologic cure, relapse, and treatment-failure as endpoints to define the best regimen for focal disease.
Show evidence (1 reference)
PMID:18045560 SUPPORT Other
"the development of improved treatment regimens"
Authoritative review naming the development of improved treatment regimens as an unresolved challenge in human brucellosis.
Which biomarkers predict disease severity, progression to focal or chronic disease, relapse risk, and treatment response in human brucellosis?
KNOWLEDGE GAP OPEN gap_brucellosis_prognostic_biomarkers
Attached to
pathophysiology#Persistent multisystem infection
Brucellosis is relapse-prone and can localize to bone, heart, and the nervous system, yet there is no validated marker to stratify which patients will progress, relapse, or fail therapy. The absence of severity/progression/ treatment-response markers is a long-standing, explicitly stated gap that limits risk-adapted treatment intensity and duration.
Proposed experiments
Prospective biomarker cohort for relapse and focal-progression prediction
prospective cohort study Relation: this experiment is of type this experiment type This experiment is of type prospective cohort study.
exp_brucellosis_biomarker_cohort
Follow a prospective cohort of culture- or serology-confirmed cases with serial serologic titers, inflammatory markers, and host-immune profiling from diagnosis through completion of therapy and relapse surveillance, to identify candidate biomarkers that predict focal progression, relapse, and treatment failure.
Show evidence (1 reference)
PMID:18045560 SUPPORT Other
"the identification of markers for disease severity, progression, and treatment response"
Authoritative review naming the lack of markers for severity, progression, and treatment response as an unresolved challenge.
Does the IFN-gamma-induced MHC-I surface down-modulation by Brucella abortus RNA, shown in human epithelial, endothelial, and monocyte/macrophage cell lines in vitro, actually operate in vivo to sustain chronic human brucellosis, or is it a feature of the isolated-RNA cell-line system?
HUMAN MODEL MISMATCH OPEN gap_brucellosis_mhc_evasion_human_relevance
Attached to
pathophysiology#MHC-I surface down-modulation pathophysiology#Persistent multisystem infection
The MHC-I down-modulation immune-evasion mechanism is supported entirely by in vitro experiments using human cell lines exposed to isolated B. abortus RNA. Whether this pathway meaningfully impairs CD8+ T-cell surveillance in infected patients — and thereby drives the persistence and relapse that define chronic brucellosis — has not been demonstrated in human tissue or in an in vivo model of chronic infection, so its translational weight is uncertain. Understanding Brucella pathogenic mechanisms remains an explicitly stated open challenge.
Proposed experiments
In vivo test of MHC-I down-modulation and CD8 surveillance in chronic brucellosis
controlled perturbation experiment Relation: this experiment is of type this experiment type This experiment is of type controlled perturbation experiment.
exp_brucellosis_mhc_invivo
Assess surface MHC-I expression and CD8+ T-cell responses in cells from a chronic-infection animal model and in tissue or peripheral cells from patients with chronic or relapsing brucellosis, comparing infected versus uninfected states to test whether the in-vitro MHC-I down-modulation operates during genuine intracellular infection.
Show evidence (1 reference)
PMID:18045560 SUPPORT Other
"the understanding of pathogenic mechanisms of Brucella spp"
Authoritative review naming the understanding of Brucella pathogenic mechanisms as an unresolved challenge, underscoring the translational gap for this in-vitro mechanism.
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Pathophysiology

18
Zoonotic acquisition and inoculation
Entry of Brucella into the human host from infected animals or their products. Acquisition is occupational for breeders, veterinarians, abattoir and laboratory workers through direct contact with animals, birth products and aerosols, and food-borne for the general public through raw milk and unpasteurized dairy. Human-to-human transmission is anecdotal, so essentially every human case begins at an animal reservoir. This is the proximal step the rest of this entry assumes: every other pathophysiology node here is downstream of established infection.
Downstream
Intracellular macrophage survival Inoculated organisms cross the mucosal or cutaneous barrier and are taken up by phagocytes, which is how the intracellular niche modeled downstream is established. Mucosal penetration and phagocytic uptake are the known intervening steps and are not separate nodes in this entry.
Show evidence (3 references)
PMID:37630630 SUPPORT Other
"Thus, risk groups are breeders and their families, veterinarians, laboratory personnel and dairy and slaughterhouse workers."
Names the occupational groups in whom acquisition occurs, which is the exposure route half of this node.
PMID:37630630 SUPPORT Other
"The general public is mainly affected by consuming raw milk and unpasteurized dairy products and, to a lesser extent, raw viscera, blood and offal"
Names the food-borne route, the second half of how the organism reaches the human host.
PMID:22081201 SUPPORT Other
"Transmission of brucellosis to humans occurs through the consumption of infected, unpasteurized animal milk and milk products, through direct contact with infected animal parts, through ruptures of skin and mucous membranes and through the inhalation of infected aerosolized particles."
Enumerates every route this node's description asserts in a single sentence, including the inhalational route that the One Health review does not mention.
Intracellular macrophage survival
Brucella can survive inside macrophages, establishing an intracellular niche that supports persistence and immune evasion.
macrophage CL:0000235 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves macrophage (CL:0000235). CL:0000235 is a cell type from the Cell Ontology.
defense response to Gram-negative bacterium GO:0050829 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves dysregulated defense response to Gram-negative bacterium (GO:0050829). GO:0050829 is a biological process from the Gene Ontology. ↕ DYSREGULATED
Downstream
MHC-I surface down-modulation Intracellular infection context is linked to reduced MHC-I surface expression and impaired CD8+ T-cell surveillance.
Show evidence (1 reference)
DOI:10.1371/journal.pone.0306429 SUPPORT In Vitro
"Brucella abortus (Ba) is a pathogen that survives inside macrophages."
Supports macrophage intracellular survival as a core Brucella pathogenesis feature.
MHC-I surface down-modulation
Brucella abortus RNA reduces IFN-gamma-induced surface MHC-I expression in epithelial, endothelial, and monocyte/macrophage contexts.
bronchial epithelial cell CL:0002328 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves bronchial epithelial cell (CL:0002328). CL:0002328 is a cell type from the Cell Ontology. endothelial cell CL:0000115 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves endothelial cell (CL:0000115). CL:0000115 is a cell type from the Cell Ontology. monocyte CL:0000576 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves monocyte (CL:0000576). CL:0000576 is a cell type from the Cell Ontology. macrophage CL:0000235 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves macrophage (CL:0000235). CL:0000235 is a cell type from the Cell Ontology.
antigen processing and presentation GO:0019882 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased antigen processing and presentation (GO:0019882). GO:0019882 is a biological process from the Gene Ontology. ↓ DECREASED
Downstream
Persistent multisystem infection Impaired MHC-I surface expression may help Brucella persist by reducing CD8+ T-cell surveillance.
Show evidence (2 references)
DOI:10.1371/journal.pone.0306429 SUPPORT In Vitro
"Here, we demonstrate that Ba RNA reduced the surface expression of MHC-I induced by IFN-γ in the human bronchial epithelium (Calu-6), the human alveolar epithelium (A-549) and the endothelial microvasculature (HMEC) cell lines."
Supports MHC-I surface down-modulation in non-myeloid human cell models.
DOI:10.1371/journal.pone.0306429 SUPPORT In Vitro
"In addition, we showed that Ba RNA down-modulates the MHC-I surface expression induced by IFN-γ on human monocytes/macrophages via the pathway of the Epidermal Growth Factor Receptor (EGFR)."
Supports MHC-I down-modulation in monocytes/macrophages and implicates EGFR pathway involvement.
Pro-inflammatory cytokine induction in epithelial and endothelial cells
Brucella abortus RNA can increase IL-8 and IL-6 secretion in epithelial and endothelial cell models.
epithelial cell CL:0000066 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves epithelial cell (CL:0000066). CL:0000066 is a cell type from the Cell Ontology. endothelial cell CL:0000115 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves endothelial cell (CL:0000115). CL:0000115 is a cell type from the Cell Ontology.
regulation of cytokine production GO:0001817 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased regulation of cytokine production (GO:0001817). GO:0001817 is a biological process from the Gene Ontology. ↑ INCREASED inflammatory response GO:0006954 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased inflammatory response (GO:0006954). GO:0006954 is a biological process from the Gene Ontology. ↑ INCREASED
Downstream
Fever Inflammatory cytokine signaling contributes to systemic febrile illness.
Show evidence (1 reference)
DOI:10.1371/journal.pone.0306429 SUPPORT In Vitro
"Contrary to our expectations, HMEC, Calu-6 and A-549 cells treated with Ba RNA had higher IL-8 and IL-6 levels compared to untreated cells."
Supports cytokine induction in epithelial and endothelial cell lines after Brucella RNA exposure.
Persistent multisystem infection
Brucellosis involves difficult-to-clear infection requiring prolonged combination therapy to clear infection and prevent relapse.
defense response to bacterium GO:0042742 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves dysregulated defense response to bacterium (GO:0042742). GO:0042742 is a biological process from the Gene Ontology. ↕ DYSREGULATED
Downstream
Systemic constitutional illness Persistent systemic infection produces the characteristic constitutional and musculoskeletal symptom complex.
Hematogenous dissemination Persistent infection enters the bloodstream and disseminates to distant tissues.
Show evidence (1 reference)
DOI:10.1038/s41598-024-69669-w SUPPORT Human Clinical
"Brucellosis is a difficult to treat infection that requires antibiotic combinations administered over several weeks for clearance of infection and relapse prevention."
Supports persistent, relapse-prone infection as a clinical pathophysiology node.
Systemic constitutional illness
Human brucellosis commonly manifests as a systemic febrile illness with fatigue, malaise, sweats, musculoskeletal pain, headache, and weight loss.
Downstream
Fatigue Fatigue is a frequent constitutional manifestation of systemic brucellosis.
Joint pain Arthralgia is a frequent musculoskeletal manifestation of systemic brucellosis.
Back pain Back pain is a common symptom in the general musculoskeletal complex and is not assumed to represent focal axial infection in every patient.
Malaise Malaise is a frequent constitutional manifestation of systemic brucellosis.
Sweats Sweating is a frequent constitutional manifestation of systemic brucellosis.
Myalgia Myalgia is a frequent musculoskeletal manifestation of systemic brucellosis.
Headache Headache is a frequent constitutional manifestation of systemic brucellosis.
Weight loss Weight loss accompanies the systemic illness of brucellosis.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"arthralgia, myalgia and back pain affected around half of the patients (65%, 47% and 45%, respectively)"
Supports the systemic constitutional and musculoskeletal illness pattern in human brucellosis.
Hematogenous dissemination
Brucella bacteraemia distributes organisms from the persistent systemic reservoir to distant tissues.
Downstream
Osteoarticular seeding Bloodstream dissemination permits focal infection of joints, sacroiliac joints, and vertebral structures.
Cardiac valve seeding Bloodstream organisms can establish focal valvular infection.
Central nervous system invasion Bloodstream dissemination can lead to focal neurologic infection.
Genitourinary seeding Bloodstream dissemination can establish focal infection in the epididymis and testis.
Placental infection Maternal infection can involve the placenta and threaten pregnancy.
Reticuloendothelial organ seeding Bloodstream organisms can localize in liver and spleen.
Abdominal organ involvement Disseminated brucellosis can involve abdominal organs and produce abdominal pain.
Show evidence (1 reference)
DOI:10.1017/S0950268824000803 SUPPORT Human Clinical
"Of 2,489 unique cases, 99.8% were bacteraemic"
A national culture-confirmed cohort documents near-universal bloodstream involvement.
Osteoarticular seeding
Focal osteoarticular infection affects peripheral joints, sacroiliac joints, or vertebral structures.
Downstream
Arthritis Peripheral joint infection may manifest as arthritis.
Sacroiliitis Sacroiliac focal infection manifests as sacroiliitis.
Spondylitis Vertebral focal infection manifests as spondylitis.
Cardiac valve seeding
Focal Brucella infection of cardiac valves produces endocarditis.
Downstream
Endocarditis Valvular infection manifests as endocarditis.
Central nervous system invasion
Focal neurologic infection produces neurobrucellosis.
Downstream
Neurobrucellosis CNS involvement may manifest as meningitis or meningoencephalitis.
Genitourinary seeding
Focal genitourinary infection affects the epididymis and testis.
Downstream
Epididymo-orchitis Epididymal and testicular infection manifests as epididymo-orchitis.
Placental infection
Maternal brucellosis can compromise pregnancy through placental involvement.
Downstream
Miscarriage Maternal infection may result in miscarriage.
Premature birth Maternal infection may result in premature birth.
Reticuloendothelial organ seeding
Focal infection of liver and spleen produces organ enlargement.
Downstream
Hepatosplenomegaly Combined liver and spleen enlargement is documented in maternal-child brucellosis.
Splenomegaly Splenic involvement manifests as splenomegaly.
Hepatomegaly Hepatic involvement manifests as hepatomegaly.
Abdominal organ involvement
Disseminated abdominal involvement produces abdominal pain.
Downstream
Abdominal pain Abdominal involvement manifests as abdominal pain.
Facultative Intracellular Niche (Cell-Penetrant Drug Requirement)
Brucella is a facultative intracellular pathogen that survives and replicates within host phagocytes (chiefly macrophages). This intracellular lifestyle shields the organism from antibodies and complement and, critically for therapy, from antibiotics that cannot accumulate inside eukaryotic cells — notably the beta-lactams. Effective treatment is therefore restricted to cell-penetrant agents (doxycycline, aminoglycosides that concentrate at the site, rifampicin), and cure requires prolonged combination therapy to reach and clear the protected intracellular reservoir. This is the lifestyle-gating principle that constrains drug choice beyond any single molecular target.
macrophage CL:0000235 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves macrophage (CL:0000235). CL:0000235 is a cell type from the Cell Ontology.
Biological Process Involved in Interaction with Host GO:0051701 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves Biological Process Involved in Interaction with Host (GO:0051701). GO:0051701 is a biological process from the Gene Ontology.
Downstream
Requirement for Cell-Penetrant Antimicrobials Because the intracellular niche excludes poorly penetrant drugs, effective brucellosis therapy is restricted to agents that accumulate inside host cells.
Show evidence (2 references)
DOI:10.1371/journal.pone.0306429 SUPPORT In Vitro
"Brucella abortus (Ba) is a pathogen that survives inside macrophages."
Supports the facultative intracellular (macrophage-resident) niche that underlies the cell-penetrant-drug requirement.
PMID:18611821 SUPPORT Other
"The intracellular location of some microorganisms allow them to resist antibiotics with poor ability to penetrate eukaryotic cell membranes, such as the beta-lactam compounds."
Review establishing that the intracellular niche confers resistance to poorly cell-penetrant antibiotics such as beta-lactams, the gating principle this node represents. Evidence source is OTHER as this is a review article.
Requirement for Cell-Penetrant Antimicrobials
Efficacy against the intracellular Brucella reservoir tracks the intracellular concentration a drug achieves, not merely its in vitro MIC. Doxycycline, rifampicin, and aminoglycosides accumulate within (or otherwise reach) infected cells, whereas beta-lactams do not — so the mainstay regimens are built from cell-penetrant agents given in prolonged combination. This is the cell-penetrant-drug requirement that the brucellosis treatments target.
Response to Antibiotic GO:0046677 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves Response to Antibiotic (GO:0046677). GO:0046677 is a biological process from the Gene Ontology.
Show evidence (1 reference)
PMID:28639230 SUPPORT Other
"Therapeutic efficacy against intracellular pathogens has been correlated mainly with the intracellular concentrations achieved by the different antimicrobial agents."
Review establishing that efficacy against intracellular pathogens depends on the intracellular concentration achieved — the cell-penetrant requirement this node represents. Evidence source is OTHER as this is a review article.
Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target)
Brucella, like other bacteria, depends on 70S-ribosome translation of its mRNA. Doxycycline (a tetracycline) binds the 30S subunit and blocks aminoacyl-tRNA delivery, and the aminoglycosides streptomycin and gentamicin also target the 30S ribosome — the shared molecular target that anchors the doxycycline-plus-aminoglycoside brucellosis regimens. This is a bacterial target absent from the beta-lactam-inaccessible host cytoplasm, complementing the intracellular-niche gating node.
Translation GO:0006412 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves Translation (GO:0006412). GO:0006412 is a biological process from the Gene Ontology.
Show evidence (1 reference)
PMID:24336183 SUPPORT Other
"The ribosome is one of the main antibiotic targets in the bacterial cell."
Review establishing the bacterial ribosome as the target of tetracyclines and aminoglycosides, the protein-synthesis-inhibition step this node represents. Evidence source is OTHER as this is a review article.
Bacterial RNA Polymerase (Rifamycin Target)
Rifampicin, a component of the classic WHO-recommended doxycycline-rifampicin regimen, binds the beta subunit of bacterial DNA-dependent RNA polymerase and blocks nascent-transcript elongation. Because rifamycins are cell- and tissue-penetrant, this target is reachable in the intracellular Brucella reservoir; single rpoB point mutations confer high-level resistance, which is part of why rifampicin is used in combination rather than alone.
DNA-Templated Transcription GO:0006351 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves DNA-Templated Transcription (GO:0006351). GO:0006351 is a biological process from the Gene Ontology.
Show evidence (1 reference)
PMID:32342856 SUPPORT Other
"The most clinically important and extensively studied class of antibiotics known to inhibit bacterial RNAP are the rifamycins."
Review establishing bacterial RNA polymerase as the rifamycin target, the transcription-inhibition step this node represents. Evidence source is OTHER as this is a review article.
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Pathograph

Use the checkboxes to hide or show graph categories. Hover nodes for evidence and cross-linked metadata.
Pathograph: causal mechanism network for Brucellosis Interactive directed graph showing how pathophysiology mechanisms, phenotypes, genetic factors and variants, experimental models, environmental triggers, and treatments relate through causal and linked edges.
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Phenotypes

21
Cardiovascular 2
Hepatosplenomegaly HP:0001433 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hepatosplenomegaly (HP:0001433). HP:0001433 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
DOI:10.1186/s43088-024-00569-8 SUPPORT Human Clinical
"Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
Supports hepatosplenomegaly as a documented complication in maternal-child brucellosis literature.
Splenomegaly OCCASIONAL HP:0001744 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Splenomegaly (HP:0001744). HP:0001744 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Splenomegaly 9 31 (19; 43) 13 24 (18; 31) 14 25 (17; 34) 36 26 (21; 31)"
Peer-reviewed systematic review Table 2; splenomegaly in 26% of cases (all ages), an OCCASIONAL band.
Digestive 1
Hepatomegaly OCCASIONAL HP:0002240 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hepatomegaly (HP:0002240). HP:0002240 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Hepatomegaly 10 27 (15; 41) 13 22 (16; 26) 14 22 (15; 29) 37 23 (19; 27)"
Peer-reviewed systematic review Table 2; hepatomegaly in 23% of cases (all ages), an OCCASIONAL band.
Immune 1
Neurobrucellosis VERY_RARE Meningitis HP:0001287 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Neurobrucellosis, annotated with Meningitis (HP:0001287). HP:0001287 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Neurological 5 2 (1; 4) 11 5 (3; 7) 10 4 (2; 6) 26 4 (3; 5)"
Peer-reviewed systematic review Table 2; neurological (neurobrucellosis) involvement in 4% of cases (all ages), a VERY_RARE band.
Integument 1
Sweats FREQUENT Hyperhidrosis HP:0000975 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Sweats, annotated with Hyperhidrosis (HP:0000975). HP:0000975 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Sweats 8 23 (11; 37) 14 55 (35; 74) 12 73 (60; 85) 34 54 (42; 66)"
Peer-reviewed systematic review Table 2; sweats in 54% of cases (all ages), a FREQUENT band.
Metabolism 1
Fever FREQUENT HP:0001945 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Fever (HP:0001945). HP:0001945 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Given that 78% patients had fever, brucellosis poses a diagnostic challenge in malaria-endemic areas"
Peer-reviewed systematic review; pooled 78% of cases had fever, supporting a FREQUENT (30-79%) band and replacing a preprint citation.
Musculoskeletal 2
Arthritis OCCASIONAL HP:0001369 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Arthritis (HP:0001369). HP:0001369 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Arthralgia was common, affecting 65% patients overall, whereas arthritis affected only 26% patients"
Peer-reviewed systematic review; frank arthritis affected 26% of cases overall, supporting an OCCASIONAL band and replacing a methods-list quote.
Spondylitis OCCASIONAL HP:0033631 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Spondylitis (HP:0033631). HP:0033631 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Spondylitis 1 18 (1; 28)* 6 12 (7, 19) 9 11 (6; 18) 16 12 (8; 17)"
Peer-reviewed systematic review Table 2; spondylitis in 12% of cases (all ages), an OCCASIONAL band.
Nervous System 1
Headache FREQUENT HP:0002315 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Headache (HP:0002315). HP:0002315 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Headache 6 9 (5; 15) 11 34 (19; 50) 11 52 (32; 72) 28 35 (24; 46)"
Peer-reviewed systematic review Table 2; headache in 35% of cases (all ages), a FREQUENT band.
Prenatal and Birth 1
Premature birth OCCASIONAL HP:0001622 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Premature birth (HP:0001622). HP:0001622 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
DOI:10.1186/s43088-024-00569-8 SUPPORT Human Clinical
"Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
The scoping review documents preterm birth in 20% of the maternal brucellosis literature summarized, supporting an OCCASIONAL band.
Constitutional 6
Fatigue FREQUENT HP:0012378 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Fatigue (HP:0012378). HP:0012378 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Fatigue 2 19 (13; 23) 2 33 (13; 100) 5 51 (27; 75) 9 39 (16; 65)"
Peer-reviewed systematic review Table 2; fatigue in 39% of cases (all ages), supporting a FREQUENT band and replacing a preprint citation.
Joint pain FREQUENT Arthralgia HP:0002829 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Joint pain, annotated with Arthralgia (HP:0002829). HP:0002829 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"arthralgia, myalgia and back pain affected around half of the patients (65%, 47% and 45%, respectively)"
Peer-reviewed systematic review; arthralgia affected 65% of cases, supporting a FREQUENT (30-79%) band and replacing a preprint citation.
Malaise FREQUENT HP:0033834 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Malaise (HP:0033834). HP:0033834 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Malaise 2 24 (16; 34) 6 81 (71; 89) 8 74 (48; 93) 16 71 (57; 83)"
Peer-reviewed systematic review Table 2; malaise in 71% of cases (all ages), a FREQUENT band.
Myalgia FREQUENT HP:0003326 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Myalgia (HP:0003326). HP:0003326 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Myalgia 2 18 (11; 26) 5 56 (38; 75) 8 49 (36; 63) 15 47 (38; 57)"
Peer-reviewed systematic review Table 2; myalgia in 47% of cases (all ages), a FREQUENT band.
Back pain FREQUENT HP:0003418 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Back pain (HP:0003418). HP:0003418 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Back pain 1 10 (3; 21)* 11 49 (31; 67) 11 45 (31; 60) 23 45 (34; 56)"
Peer-reviewed systematic review Table 2; back pain in 45% of cases (all ages), a FREQUENT band.
Abdominal pain OCCASIONAL HP:0002027 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Abdominal pain (HP:0002027). HP:0002027 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Abdominal pain 3 14 (1; 38) 4 9 (1; 22) 9 26 (13; 41) 16 19 (11; 29)"
Peer-reviewed systematic review Table 2; abdominal pain in 19% of cases (all ages), an OCCASIONAL band.
Growth 1
Weight loss OCCASIONAL HP:0001824 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Weight loss (HP:0001824). HP:0001824 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Weight loss 3 13(8;18) 4 31 (15; 50) 7 29 (15; 47) 14 26 (17; 36)"
Peer-reviewed systematic review Table 2; weight loss in 26% of cases (all ages), an OCCASIONAL band.
Other 4
Endocarditis VERY_RARE HP:0100584 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Endocarditis (HP:0100584). HP:0100584 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Severe complications of brucellosis infection were not rare, with 1 case of endocarditis and 4 neurological cases per 100 patients"
Peer-reviewed systematic review; endocarditis occurred in ~1 per 100 cases, supporting a VERY_RARE (<5%) band and replacing a preprint citation.
Sacroiliitis OCCASIONAL Sacroiliac arthritis HP:0012317 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Sacroiliitis, annotated with Sacroiliac arthritis (HP:0012317). HP:0012317 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Overall, spondylitis and sacroiliitis were detected in 12–36% adults"
Peer-reviewed systematic review; osteoarticular focal disease (spondylitis/sacroiliitis) detected in 12–36% of adults, supporting an OCCASIONAL band.
Epididymo-orchitis OCCASIONAL HP:0100796 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Epididymo-orchitis, annotated with Orchitis (HP:0100796). HP:0100796 is a phenotype from the Human Phenotype Ontology.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"One in 10 men experienced epididymo-orchitis, the most common genitourinary complication of brucellosis infection"
Peer-reviewed systematic review; epididymo-orchitis in ~10% of male cases (OCCASIONAL band, male denominator) and the most common genitourinary complication.
Miscarriage OCCASIONAL
No phenotype term is assigned because the available miscarriage terms are not currently reachable from the disease-entry phenotype root used by this schema.
Show evidence (2 references)
DOI:10.1186/s43088-024-00569-8 SUPPORT Human Clinical
"Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
The scoping review documents miscarriage in 25% of the maternal brucellosis literature summarized, supporting an OCCASIONAL band.
PMID:23236528 SUPPORT Human Clinical
"only one study reported abortion rates as a proportion of pregnant female participants, which was 46%"
A single contributing study supplies additional pregnancy-specific evidence but is not used to replace the broader 25% frequency estimate.
💊

Medical Actions

4
Doxycycline-rifampicin combination therapy
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: doxycycline CHEBI:50845 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses doxycycline (CHEBI:50845). CHEBI:50845 is a therapeutic agent from Chemical Entities of Biological Interest. rifampicin CHEBI:28077 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses rifampicin (CHEBI:28077). CHEBI:28077 is a therapeutic agent from Chemical Entities of Biological Interest.
Standard oral dual antibiotic therapy used for uncomplicated human brucellosis and bacteremic disease, though relapse risk can be higher than with some aminoglycoside-containing regimens.
Mechanism Target:
INHIBITS Persistent multisystem infection — Combination antibiotic therapy targets clearance of persistent infection and prevention of relapse.
Show evidence (1 reference)
DOI:10.1038/s41598-024-69669-w SUPPORT Human Clinical
"Brucellosis is a difficult to treat infection that requires antibiotic combinations administered over several weeks for clearance of infection and relapse prevention."
Supports using prolonged combination therapy to clear infection and reduce relapse.
INHIBITS Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target) — Doxycycline binds the 30S ribosome and arrests bacterial protein synthesis.
INHIBITS Bacterial RNA Polymerase (Rifamycin Target) — Rifampicin binds bacterial RNA polymerase and blocks transcription.
INHIBITS Requirement for Cell-Penetrant Antimicrobials — Both agents are cell-penetrant and so reach the intracellular Brucella reservoir that beta-lactams cannot.
Show evidence (2 references)
DOI:10.1038/s41598-024-69669-w SUPPORT Human Clinical
"However, the latter is also efficacious and suitable for uncomplicated disease."
In context, supports doxycycline-rifampicin as an efficacious uncomplicated-disease option despite better outcomes for some triple therapies.
DOI:10.37723/jumdc.v15i3.920 SUPPORT Human Clinical
"CONCLUSION: Oral doxycycline-rifampicin (DR) and IV gentamicin-doxycycline-rifampicin (GDR) regimens have similar response rates in bacteremia brucellosis."
Supports oral doxycycline-rifampicin as a bacteremic brucellosis regimen in an observational comparison.
Doxycycline-streptomycin combination therapy
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: doxycycline CHEBI:50845 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses doxycycline (CHEBI:50845). CHEBI:50845 is a therapeutic agent from Chemical Entities of Biological Interest. streptomycin CHEBI:17076 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses streptomycin (CHEBI:17076). CHEBI:17076 is a therapeutic agent from Chemical Entities of Biological Interest.
Aminoglycoside-containing combination therapy with evidence of superior efficacy compared with doxycycline-rifampicin in network meta-analyses.
Mechanism Target:
INHIBITS Persistent multisystem infection — Aminoglycoside-containing doxycycline therapy is used to improve clearance and reduce relapse risk.
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012010 SUPPORT Human Clinical
"This review confirmed the superiority of drugs already indicated for treating human brucellosis, such as the combination of doxycycline and aminoglycosides."
Supports an aminoglycoside-containing doxycycline regimen as a superior brucellosis treatment strategy.
INHIBITS Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target) — Both doxycycline and streptomycin bind the 30S ribosome and arrest bacterial protein synthesis.
INHIBITS Requirement for Cell-Penetrant Antimicrobials — Doxycycline reaches the intracellular reservoir; the aminoglycoside adds bactericidal activity for prolonged-course cure.
Show evidence (2 references)
DOI:10.1371/journal.pntd.0012405 SUPPORT Human Clinical
"Brucellosis medications differ in efficacy and safety. Doxycycline + Gentamicin, Triple, and Doxycycline + Streptomycin have superior efficacy and safety."
Supports doxycycline-streptomycin as a high-performing regimen class.
DOI:10.1038/s41598-024-69669-w SUPPORT Human Clinical
"Triple antibiotic therapy is more effective than standard dual therapy with rifampicin and doxycycline."
Supports intensifying beyond standard dual therapy for improved treatment outcomes.
Doxycycline-gentamicin combination therapy
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: doxycycline CHEBI:50845 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses doxycycline (CHEBI:50845). CHEBI:50845 is a therapeutic agent from Chemical Entities of Biological Interest. gentamicin CHEBI:17833 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses gentamicin, annotated with gentamycin (CHEBI:17833). CHEBI:17833 is a therapeutic agent from Chemical Entities of Biological Interest.
Aminoglycoside-containing combination therapy that ranked highest for efficacy (SUCRA 0.94) in a 2024 network meta-analysis of randomized trials. Scope caveat: that meta-analysis restricted inclusion to trials of children and adolescents (pooled trial population aged 13-70), the doxycycline-gentamicin top ranking rested on only 2 trials, and the authors state their recommendations are not applicable to young children (<8 years), pregnant women, or focal disease such as spondylitis, endocarditis, and neurobrucellosis.
Mechanism Target:
INHIBITS Persistent multisystem infection — Doxycycline-gentamicin therapy is used to improve infection clearance and prevent treatment failure.
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012405 SUPPORT Human Clinical
"Doxycycline + Gentamicin ranked the best in efficacy (SUCRA values: 0.94), the second is Triple (SUCRA values: 0.87), and the third is Doxycycline + Streptomycin (SUCRA values: 0.78)."
Supports doxycycline-gentamicin as the top-ranked efficacy regimen in the network meta-analysis, whose inclusion was restricted to children/adolescents and rested on only 2 gentamicin-arm trials.
INHIBITS Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target) — Both doxycycline and gentamicin bind the 30S ribosome and arrest bacterial protein synthesis.
INHIBITS Requirement for Cell-Penetrant Antimicrobials — Doxycycline reaches the intracellular reservoir; gentamicin adds bactericidal activity during the initial course.
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012405 SUPPORT Human Clinical
"Doxycycline + Gentamicin ranked the best in efficacy (SUCRA values: 0.94), the second is Triple (SUCRA values: 0.87), and the third is Doxycycline + Streptomycin (SUCRA values: 0.78)."
Supports doxycycline-gentamicin as a high-efficacy brucellosis regimen; the network meta-analysis restricted inclusion to children/adolescents and the gentamicin arm comprised only 2 trials.
Doxycycline-streptomycin-hydroxychloroquine triple therapy
Action: PharmacotherapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is Pharmacotherapy (NCIT:C15986). NCIT:C15986 is a clinical intervention from the NCI Thesaurus. NCIT:C15986
Agent: doxycycline CHEBI:50845 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses doxycycline (CHEBI:50845). CHEBI:50845 is a therapeutic agent from Chemical Entities of Biological Interest. streptomycin CHEBI:17076 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses streptomycin (CHEBI:17076). CHEBI:17076 is a therapeutic agent from Chemical Entities of Biological Interest. hydroxychloroquine CHEBI:5801 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses hydroxychloroquine (CHEBI:5801). CHEBI:5801 is a therapeutic agent from Chemical Entities of Biological Interest.
Emerging triple therapy identified as a potential strategy to reduce overall therapy failure, with very low-certainty evidence requiring confirmation.
Mechanism Target:
INHIBITS Persistent multisystem infection — Hydroxychloroquine-containing triple therapy may reduce treatment failure, but evidence remains low certainty and investigational.
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012010 SUPPORT Human Clinical
"The association of hydroxychloroquine to the dual regimen was identified as a potential strategy to prevent overall therapy failure, which is subject to confirmation in future studies."
Supports the regimen as a promising but not yet definitive treatment strategy.
INHIBITS Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target) — The doxycycline and streptomycin backbone binds the 30S ribosome and arrests bacterial protein synthesis.
INHIBITS Requirement for Cell-Penetrant Antimicrobials — Hydroxychloroquine alkalinizes the acidic Brucella-containing vacuole to improve intracellular aminoglycoside/doxycycline activity against the protected reservoir.
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012010 SUPPORT Human Clinical
"The association of hydroxychloroquine to the dual regimen was identified as a potential strategy to prevent overall therapy failure, which is subject to confirmation in future studies."
Conservatively supports hydroxychloroquine triple therapy as emerging/partial evidence pending confirmation.
🌍

Environmental Factors

3
Livestock-dependent setting
Issue #8302 asked for an explicit decision on the Research Square preprint cited here rather than letting it stand by default. Decision: keep it, demoted to PARTIAL and no longer the primary support, with the peer-reviewed One Health review (PMID:37630630) carrying the claim. Its snippet does verify against the cached document; the objection was to its epistemic status, not its accuracy.
Livestock-dependent regions have higher exposure opportunity for zoonotic Brucella transmission.
Show evidence (2 references)
PMID:37630630 SUPPORT Other
"brucellosis is considered a severe problem in animals and humans in Asia, the Middle East, Africa and Ibero-America"
Peer-reviewed support for the geographic concentration of brucellosis in the regions where livestock husbandry is economically dominant.
DOI:10.21203/rs.3.rs-4929733/v1 Preprint · not peer-reviewed SUPPORT Human Clinical
"Human brucellosis caused by various Brucella species is a significant global health concern, particularly in livestock-dependent regions."
Names livestock-dependent regions directly, which no peer-reviewed source cited here does in those words. Downgraded from SUPPORT to PARTIAL because this is a Research Square preprint that has not been peer reviewed; it is retained as corroboration rather than as the item the claim rests on.
Mechanism Target:
PREDISPOSES Zoonotic acquisition and inoculation — A livestock-dependent economy is a determinant of how much contact a population has with the animal reservoir, not an exposure in itself. Proximity to infected animals and consumption of unpasteurized local dairy are the known intervening steps, and neither is a node in this graph.
Show evidence (1 reference)
PMID:37630630 SUPPORT Other
"focused on high-risk groups (animal and human health workers, livestock owners, dairy farmers, abattoir workers, pastoralists, patients, students and residents"
A 79-study, 22-country review whose high-risk groups are named as livestock owners, dairy farmers, abattoir workers and pastoralists - occupations defined by livestock dependence rather than by geography, which is what this link asserts the setting concentrates.
Maternal livestock exposure
exposure to livestock ECTO:3000000 Environmental Conditions, Treatments and Exposures Ontology (ECTO) Relation: this environmental factor is this exposure This environmental factor is exposure to livestock, annotated with exposure to organism (ECTO:3000000). ECTO:3000000 is an exposure from the Environmental Conditions, Treatments and Exposures Ontology.
Bound to ECTO:3000000 exposure to organism, the most specific applicable ECTO term - ECTO has no Brucella, livestock, or raw-milk exposure class (searched 2026-08-25). Same fallback pattern as the viral exposures bound to ECTO:3000001. This reference has no PMID: the Beni-Suef University Journal of Basic and Applied Sciences is not PubMed-indexed, so unlike the other two exposures here it cannot be moved off a DOI and remains unchecked by linkml-reference-validator. Its snippet was verified by hand against the cached document.
Show evidence (1 reference)
DOI:10.1186/s43088-024-00569-8 SUPPORT Human Clinical
"Key findings demonstrate that zoonotic brucellosis acquisition from livestock exposures among vulnerable maternal groups accounts for up to 70% of cases."
Supports livestock exposure as a maternal risk context.
Mechanism Target:
TRIGGERS Zoonotic acquisition and inoculation — Unlike the setting-level entry above, this is the exposure event itself: contact with infected livestock is how the organism reaches the host in this group, and the cited review puts the majority of cases on that route.
Show evidence (1 reference)
DOI:10.1186/s43088-024-00569-8 SUPPORT Human Clinical
"Key findings demonstrate that zoonotic brucellosis acquisition from livestock exposures among vulnerable maternal groups accounts for up to 70% of cases."
Quantifies livestock exposure as the dominant acquisition route in this group, which is exactly the node this link targets.
Inadequate One Health control infrastructure
Left unbound: this is a health-system determinant rather than an exposure, and ECTO has no class for control or surveillance infrastructure (searched 2026-08-25). Citations moved from DOI:10.3390/microorganisms11082070 to PMID:37630630, the same paper, so that linkml-reference-validator now checks these snippets instead of skipping them on the DOI prefix.
Weak surveillance, diagnostic, veterinary, and public-health infrastructure can impair brucellosis control in endemic settings.
Show evidence (2 references)
PMID:37630630 SUPPORT Other
"Brucellosis One Health actors include Public Health and Veterinary Services, microbiologists, medical and veterinary practitioners and breeders."
Supports multidisciplinary One Health control context.
PMID:37630630 SUPPORT Other
"Extended infrastructural weaknesses, often accentuated by geography and climate, are critically important."
Supports infrastructure as a risk modifier for brucellosis control.
Mechanism Target:
PREDISPOSES Zoonotic acquisition and inoculation — Control infrastructure acts on the animal reservoir rather than on the person: weak veterinary surveillance, absent herd vaccination and unenforced milk pasteurization all leave more infected animals and products in contact with people. The review documents the infrastructural weakness but does not trace it through to a case count, so the intermediates are recorded as unknown.
Show evidence (1 reference)
PMID:37630630 SUPPORT Other
"Extended infrastructural weaknesses, often accentuated by geography and climate, are critically important."
Names infrastructural weakness as critically important to brucellosis control. PARTIAL because the review argues its importance for control rather than measuring an effect on acquisition, which is what this link asserts.
🔬

Diagnosis

3
Culture and serology reference standards
Human brucellosis diagnostic studies commonly compare index tests against culture and/or standard tube agglutination testing.
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012030 SUPPORT Human Clinical
"Regarding the reference test, culture and/or SAT are deemed more appropriate than culture alone."
Supports culture and SAT as important reference standards.
Rose Bengal, ELISA, and PCR testing
Rose Bengal, IgG/IgM ELISA, and PCR are promising tools for confirming suspected human brucellosis when interpreted in context.
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012030 SUPPORT Human Clinical
"Rose Bengal, IgG/IgM ELISA, and PCR exhibited equally high performances, indicating superior overall diagnostic accuracy, with very low certainty of the evidence."
Supports these diagnostic modalities and preserves the evidence-certainty caveat.
Combined serologic diagnostic algorithm
Combining RBT with Brucellacapt and ELISA IgM/IgG improved diagnostic performance in a French reference-center study.
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012442 SUPPORT Human Clinical
"The most promising results were observed when an algorithm was built combining RBT, Brucellacapt, and ELISA for IgM and IgG (a score value of 0.5 with 90.5% for sensitivity, 99.7% for specificity, 92.4% for PPV, and 99.6% for NPV)."
Supports combined serology algorithms as a diagnostic performance improvement strategy.
📈

Progression

3
Non-specific febrile illness
Early human brucellosis often resembles other febrile illnesses, complicating timely diagnosis.
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012030 SUPPORT Human Clinical
"Brucellosis, a widely spread zoonotic disease, poses significant diagnostic challenges due to its non-specific symptoms and underreporting."
Supports an early non-specific presentation that can delay recognition.
Focal complication phase
A subset develops focal complications such as osteoarticular disease, endocarditis, and neurobrucellosis.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Severe complications of brucellosis infection were not rare, with 1 case of endocarditis and 4 neurological cases per 100 patients"
Peer-reviewed systematic review documenting focal complications (endocarditis ~1%, neurological ~4%), replacing a preprint citation.
Relapse-prone treatment course
Antibiotic regimen choice affects relapse and treatment-failure risk.
Show evidence (1 reference)
DOI:10.1038/s41598-024-69669-w SUPPORT Human Clinical
"Brucellosis is a difficult to treat infection that requires antibiotic combinations administered over several weeks for clearance of infection and relapse prevention."
Supports relapse prevention as a key temporal treatment concern.
📊

Prevalence

2
Global literature meta-analysis
Point Prevalence Unknown
The 15.49% figure is pooled seropositivity across 69 heterogeneous studies, many drawn from high-risk or suspected-case populations (abattoir workers, veterinarians, febrile patients) rather than general population samples. It reflects pooled seropositivity of the included literature, not a community-level population prevalence estimate, and should not be interpreted as a general-population prevalence band.
Show evidence (1 reference)
DOI:10.21203/rs.3.rs-4929733/v1 Preprint · not peer-reviewed SUPPORT Human Clinical
"The pooled prevalence of brucellosis was 15.49% (95% CI: 12.01–18.97), with the highest prevalence observed in Palestine (76%) and the lowest in Brazil (0.64%)."
Provides a meta-analytic pooled seropositivity estimate across heterogeneous study populations; not a general-population prevalence rate.
Culture-confirmed cases in Israel, 2004-2022
Annual Incidence 1.6 per 100,000 1–9 per 100,000
Show evidence (1 reference)
DOI:10.1017/S0950268824000803 SUPPORT Human Clinical
"The average annual incidence rates overall and for the Arab, Druze, and Jewish sectors were 1.6/100,000, 6.6/100,000, 5.5/100,000, and 0.18/100,000, respectively."
Provides population-specific incidence data from a national culture-confirmed series.
🦠

Infectious Agent

3
Brucella species
Facultative intracellular bacterial genus that causes human brucellosis.
Brucella NCBITaxon:234 NCBI Taxonomy (NCBITaxon)
Show evidence (1 reference)
DOI:10.1371/journal.pntd.0012442 SUPPORT Human Clinical
"Brucellosis, a zoonotic infectious disease caused by bacteria of the genus Brucella, remains a significant global health concern in many parts of the world."
Identifies Brucella as the causative bacterial genus.
Brucella abortus
A Brucella species used in contemporary immune-evasion mechanistic studies.
Brucella abortus NCBITaxon:235 NCBI Taxonomy (NCBITaxon)
Show evidence (1 reference)
DOI:10.1371/journal.pone.0306429 SUPPORT In Vitro
"Brucella abortus (Ba) is a pathogen that survives inside macrophages."
Supports B. abortus as a disease-relevant Brucella species in host-cell infection models.
Brucella melitensis
Dominant Brucella species in a national culture-confirmed human brucellosis series from Israel.
Brucella melitensis NCBITaxon:29459 NCBI Taxonomy (NCBITaxon)
Show evidence (1 reference)
DOI:10.1017/S0950268824000803 SUPPORT Human Clinical
"Brucella melitensis was the dominant species (99.6%)."
Supports B. melitensis as a major causative species in culture-confirmed human brucellosis.
↔️

Transmission

2
Livestock-associated zoonotic exposure
Brucellosis is acquired from animal reservoirs and contaminated animal products, especially unpasteurized dairy and direct contact with infected livestock.
Show evidence (1 reference)
PMID:23236528 SUPPORT Human Clinical
"Brucellosis is a bacterial disease transmitted to humans by consumption of infected, unpasteurised animal milk or through direct contact with infected animals, particularly aborted foetuses"
Peer-reviewed systematic review documenting the two dominant zoonotic transmission routes (unpasteurized milk and direct animal contact), replacing a preprint citation.
Maternal and vertical transmission contexts
Maternal brucellosis can involve livestock exposure and vertical transmission during pregnancy, delivery, or breastfeeding.
Show evidence (1 reference)
DOI:10.1186/s43088-024-00569-8 SUPPORT Human Clinical
"Vertical transmission from mother to child during pregnancy, delivery, or breastfeeding was reported in 15–20% of cases."
Supports vertical transmission as a special-context route.
📊

Related Datasets

3
Evaluation of immunological factors involved in initiation of chronic brucellosis in CD4+ T cells using miRNA array geo:GSE107554
Brucellosis is a serious infectious disease and continues to be an important cause of morbidity. It can be seen almost anywhere in the world and at any age. Acute phase heals or becomes chronic form. Infection of 10-30% of patients becomes chronic, despite early diagnosis and treatment. Although our knowledge about Brucella virulence factors and the host response increase rapidly, how they can hidden from the immune system and cause chronic disease are still unknown. We aimed to investigate the immunological factors which belong to CD4+ T cells and their roles in the transition of brucellosis from acute to chronic infection.
human MICROARRAY n=23
PMID:29897958
Identified by GEO DataSets index search for Brucellosis (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
Refining brucellosis diagnosis by blood transcriptional profiling. geo:GSE69597
Diagnosis of brucellosis remains challenging for several reasons, including lack of culture sensitivity, nonspecific symptomatology, and high prevalence of positive serology in endemic areas. The main objectives of this study were to identify blood biomarkers specific to brucellosis compared to other endemic infections and to monitor changes in blood biomarkers during treatment. To obtain a global profile of the disease, we employed RNA sequencing (RNAseq) of whole blood RNA to measure host response against brucellosis infection in patients from Macedonia and Spain.
human BULK RNA SEQ n=169
Identified by GEO DataSets index search for Brucellosis (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
MICRORNA EXPRESSİON PATTERNS OF CD8+ T CELLS IN ACUTE AND CHRONIC BRUCELLOSIS geo:GSE87537
Using miRNA microarray, more than 2000 miRNAs were screened in CD8 + T cells of patients with acute or chronic brucellosis and healthy controls that were sorted from peripheral blood with flow cytometry and validated through qRT-PCR.
human MICROARRAY n=23
Identified by GEO DataSets index search for Brucellosis (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
{ }

Source YAML

click to show 
name: Brucellosis
creation_date: "2026-05-08T13:18:32Z"
category: Infectious Disease
description: >-
  Brucellosis is a zoonotic bacterial infection caused by Brucella species,
  typically acquired through exposure to infected animals, contaminated animal
  products, or unpasteurized dairy products. Clinical illness often presents as
  a systemic febrile syndrome and may relapse or involve focal complications.
disease_term:
  preferred_term: brucellosis
  term:
    id: MONDO:0005683
    label: brucellosis
classifications:
  harrisons_chapter:
  - classification_value: INFECTIOUS_DISEASES
    evidence:
    - reference: DOI:10.1371/journal.pntd.0012442
      reference_title: "Diagnosis of brucellosis: Combining tests to improve performance"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Brucellosis, a zoonotic infectious disease caused by bacteria of the genus Brucella, remains a significant global health concern in many parts of the world."
      explanation: Supports classification as a zoonotic infectious disease.
    - reference: PMID:16439329
      reference_title: "The new global map of human brucellosis."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "the commonest zoonotic infection worldwide"
      explanation: Peer-reviewed epidemiology review supporting classification as a globally important zoonotic bacterial infection (replaces a preprint citation).
definitions:
- name: Clinical syndrome definition
  definition_type: CASE_DEFINITION
  description: >-
    Brucellosis is a zoonotic Brucella infection with non-specific systemic
    symptoms such as fever, fatigue, and joint pain, and can cause focal
    complications including endocarditis and arthritis.
  scope: Human brucellosis clinical syndrome
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brucellosis is a bacterial disease transmitted to humans by consumption of infected, unpasteurised animal milk or through direct contact with infected animals"
    explanation: Peer-reviewed systematic review framing brucellosis as a zoonotic bacterial infection acquired from animals and animal products (replaces a preprint citation).
  - reference: DOI:10.1097/QCO.0000000000001045
    reference_title: "The many faces of brucellosis: diagnostic and management approach"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Given the global prevalence and potential complications of brucellosis, understanding recent advancements in diagnostic techniques and treatment strategies is crucial for clinicians."
    explanation: Supports the global and complicated clinical scope of brucellosis.
parents:
- zoonotic bacterial infection
- primary bacterial infectious disease
synonyms:
- undulant fever
- Malta fever
- Mediterranean flaccid fever
prevalence:
- population: Global literature meta-analysis
  measure_type: POINT_PREVALENCE
  prevalence_class: UNKNOWN
  notes: >-
    The 15.49% figure is pooled seropositivity across 69 heterogeneous studies,
    many drawn from high-risk or suspected-case populations (abattoir workers,
    veterinarians, febrile patients) rather than general population samples. It
    reflects pooled seropositivity of the included literature, not a
    community-level population prevalence estimate, and should not be interpreted
    as a general-population prevalence band.
  evidence:
  - reference: DOI:10.21203/rs.3.rs-4929733/v1
    reference_title: "Global prevalence of human brucellosis: A systematic review and meta-analysis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The pooled prevalence of brucellosis was 15.49% (95% CI: 12.01–18.97), with the highest prevalence observed in Palestine (76%) and the lowest in Brazil (0.64%)."
    explanation: Provides a meta-analytic pooled seropositivity estimate across heterogeneous study populations; not a general-population prevalence rate.
- population: Culture-confirmed cases in Israel, 2004-2022
  measure_type: ANNUAL_INCIDENCE
  prevalence_class: BAND_1_9_PER_100000
  rate_per_100000: 1.6
  evidence:
  - reference: DOI:10.1017/S0950268824000803
    reference_title: "National epidemiology of culture-confirmed brucellosis in Israel, 2004–2022"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The average annual incidence rates overall and for the Arab, Druze, and Jewish sectors were 1.6/100,000, 6.6/100,000, 5.5/100,000, and 0.18/100,000, respectively."
    explanation: Provides population-specific incidence data from a national culture-confirmed series.
infectious_agent:
- name: Brucella species
  infectious_agent_term:
    preferred_term: Brucella
    term:
      id: NCBITaxon:234
      label: Brucella
  description: Facultative intracellular bacterial genus that causes human brucellosis.
  evidence:
  - reference: DOI:10.1371/journal.pntd.0012442
    reference_title: "Diagnosis of brucellosis: Combining tests to improve performance"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brucellosis, a zoonotic infectious disease caused by bacteria of the genus Brucella, remains a significant global health concern in many parts of the world."
    explanation: Identifies Brucella as the causative bacterial genus.
- name: Brucella abortus
  infectious_agent_term:
    preferred_term: Brucella abortus
    term:
      id: NCBITaxon:235
      label: Brucella abortus
  description: A Brucella species used in contemporary immune-evasion mechanistic studies.
  evidence:
  - reference: DOI:10.1371/journal.pone.0306429
    reference_title: "Beyond its preferential niche: Brucella abortus RNA down-modulates the IFN-γ-induced MHC-I expression in epithelial and endothelial cells"
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Brucella abortus (Ba) is a pathogen that survives inside macrophages."
    explanation: Supports B. abortus as a disease-relevant Brucella species in host-cell infection models.
- name: Brucella melitensis
  infectious_agent_term:
    preferred_term: Brucella melitensis
    term:
      id: NCBITaxon:29459
      label: Brucella melitensis
  description: Dominant Brucella species in a national culture-confirmed human brucellosis series from Israel.
  evidence:
  - reference: DOI:10.1017/S0950268824000803
    reference_title: "National epidemiology of culture-confirmed brucellosis in Israel, 2004–2022"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brucella melitensis was the dominant species (99.6%)."
    explanation: Supports B. melitensis as a major causative species in culture-confirmed human brucellosis.
transmission:
- name: Livestock-associated zoonotic exposure
  description: Brucellosis is acquired from animal reservoirs and contaminated animal products, especially unpasteurized dairy and direct contact with infected livestock.
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brucellosis is a bacterial disease transmitted to humans by consumption of infected, unpasteurised animal milk or through direct contact with infected animals, particularly aborted foetuses"
    explanation: Peer-reviewed systematic review documenting the two dominant zoonotic transmission routes (unpasteurized milk and direct animal contact), replacing a preprint citation.
- name: Maternal and vertical transmission contexts
  description: Maternal brucellosis can involve livestock exposure and vertical transmission during pregnancy, delivery, or breastfeeding.
  evidence:
  - reference: DOI:10.1186/s43088-024-00569-8
    reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Vertical transmission from mother to child during pregnancy, delivery, or breastfeeding was reported in 15–20% of cases."
    explanation: Supports vertical transmission as a special-context route.
progression:
- phase: Non-specific febrile illness
  notes: Early human brucellosis often resembles other febrile illnesses, complicating timely diagnosis.
  evidence:
  - reference: DOI:10.1371/journal.pntd.0012030
    reference_title: "Diagnosis of human brucellosis: Systematic review and meta-analysis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brucellosis, a widely spread zoonotic disease, poses significant diagnostic challenges due to its non-specific symptoms and underreporting."
    explanation: Supports an early non-specific presentation that can delay recognition.
- phase: Focal complication phase
  notes: A subset develops focal complications such as osteoarticular disease, endocarditis, and neurobrucellosis.
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Severe complications of brucellosis infection were not rare, with 1 case of endocarditis and 4 neurological cases per 100 patients"
    explanation: Peer-reviewed systematic review documenting focal complications (endocarditis ~1%, neurological ~4%), replacing a preprint citation.
- phase: Relapse-prone treatment course
  notes: Antibiotic regimen choice affects relapse and treatment-failure risk.
  evidence:
  - reference: DOI:10.1038/s41598-024-69669-w
    reference_title: "A systematic review and meta-analysis of comparative clinical studies on antibiotic treatment of brucellosis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brucellosis is a difficult to treat infection that requires antibiotic combinations administered over several weeks for clearance of infection and relapse prevention."
    explanation: Supports relapse prevention as a key temporal treatment concern.
pathophysiology:
- name: Zoonotic acquisition and inoculation
  description: >-
    Entry of Brucella into the human host from infected animals or their products.
    Acquisition is occupational for breeders, veterinarians, abattoir and laboratory
    workers through direct contact with animals, birth products and aerosols, and
    food-borne for the general public through raw milk and unpasteurized dairy.
    Human-to-human transmission is anecdotal, so essentially every human case begins
    at an animal reservoir. This is the proximal step the rest of this entry assumes:
    every other pathophysiology node here is downstream of established infection.
  biological_scale: ORGANISM
  role: trigger
  downstream:
  - target: Intracellular macrophage survival
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      Inoculated organisms cross the mucosal or cutaneous barrier and are taken up by
      phagocytes, which is how the intracellular niche modeled downstream is
      established. Mucosal penetration and phagocytic uptake are the known intervening
      steps and are not separate nodes in this entry.
    evidence:
    - reference: PMID:37630630
      reference_title: "Brucellosis and One Health: Inherited and Future Challenges"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Humans contract the disease from infected animals and their products, and human-to-human transmission is only anecdotic."
      explanation: >-
        Establishes the animal-to-human route that this edge starts from. PARTIAL
        because the review states how humans acquire the organism but not the
        phagocytic uptake step that reaches the target node.
  evidence:
  - reference: PMID:37630630
    reference_title: "Brucellosis and One Health: Inherited and Future Challenges"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Thus, risk groups are breeders and their families, veterinarians, laboratory personnel and dairy and slaughterhouse workers."
    explanation: >-
      Names the occupational groups in whom acquisition occurs, which is the exposure
      route half of this node.
  - reference: PMID:37630630
    reference_title: "Brucellosis and One Health: Inherited and Future Challenges"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "The general public is mainly affected by consuming raw milk and unpasteurized dairy products and, to a lesser extent, raw viscera, blood and offal"
    explanation: >-
      Names the food-borne route, the second half of how the organism reaches the
      human host.
  - reference: PMID:22081201
    reference_title: An overview of Brucellosis.
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Transmission of brucellosis to humans occurs through the consumption of infected, unpasteurized animal milk and milk products, through direct contact with infected animal parts, through ruptures of skin and mucous membranes and through the inhalation of infected aerosolized particles."
    explanation: >-
      Enumerates every route this node's description asserts in a single sentence,
      including the inhalational route that the One Health review does not mention.
- name: Intracellular macrophage survival
  description: Brucella can survive inside macrophages, establishing an intracellular niche that supports persistence and immune evasion.
  cell_types:
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  biological_processes:
  - preferred_term: defense response to Gram-negative bacterium
    modifier: DYSREGULATED
    term:
      id: GO:0050829
      label: defense response to Gram-negative bacterium
  evidence:
  - reference: DOI:10.1371/journal.pone.0306429
    reference_title: "Beyond its preferential niche: Brucella abortus RNA down-modulates the IFN-γ-induced MHC-I expression in epithelial and endothelial cells"
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Brucella abortus (Ba) is a pathogen that survives inside macrophages."
    explanation: Supports macrophage intracellular survival as a core Brucella pathogenesis feature.
  downstream:
  - target: MHC-I surface down-modulation
    description: Intracellular infection context is linked to reduced MHC-I surface expression and impaired CD8+ T-cell surveillance.
    evidence:
    - reference: DOI:10.1371/journal.pone.0306429
      reference_title: "Beyond its preferential niche: Brucella abortus RNA down-modulates the IFN-γ-induced MHC-I expression in epithelial and endothelial cells"
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "This pathogen can evade our immune system."
      explanation: Supports immune evasion as a downstream consequence of Brucella host-cell infection.
- name: MHC-I surface down-modulation
  description: Brucella abortus RNA reduces IFN-gamma-induced surface MHC-I expression in epithelial, endothelial, and monocyte/macrophage contexts.
  cell_types:
  - preferred_term: bronchial epithelial cell
    term:
      id: CL:0002328
      label: bronchial epithelial cell
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  - preferred_term: monocyte
    term:
      id: CL:0000576
      label: monocyte
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  biological_processes:
  - preferred_term: antigen processing and presentation
    modifier: DECREASED
    term:
      id: GO:0019882
      label: antigen processing and presentation
  evidence:
  - reference: DOI:10.1371/journal.pone.0306429
    reference_title: "Beyond its preferential niche: Brucella abortus RNA down-modulates the IFN-γ-induced MHC-I expression in epithelial and endothelial cells"
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Here, we demonstrate that Ba RNA reduced the surface expression of MHC-I induced by IFN-γ in the human bronchial epithelium (Calu-6), the human alveolar epithelium (A-549) and the endothelial microvasculature (HMEC) cell lines."
    explanation: Supports MHC-I surface down-modulation in non-myeloid human cell models.
  - reference: DOI:10.1371/journal.pone.0306429
    reference_title: "Beyond its preferential niche: Brucella abortus RNA down-modulates the IFN-γ-induced MHC-I expression in epithelial and endothelial cells"
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "In addition, we showed that Ba RNA down-modulates the MHC-I surface expression induced by IFN-γ on human monocytes/macrophages via the pathway of the Epidermal Growth Factor Receptor (EGFR)."
    explanation: Supports MHC-I down-modulation in monocytes/macrophages and implicates EGFR pathway involvement.
  downstream:
  - target: Persistent multisystem infection
    description: Impaired MHC-I surface expression may help Brucella persist by reducing CD8+ T-cell surveillance.
    evidence:
    - reference: DOI:10.1371/journal.pone.0306429
      reference_title: "Beyond its preferential niche: Brucella abortus RNA down-modulates the IFN-γ-induced MHC-I expression in epithelial and endothelial cells"
      supports: SUPPORT
      evidence_source: IN_VITRO
      snippet: "In conclusion, this is the first study exploring a central immune evasion strategy, such as the downregulation of MHC-I surface expression, beyond monocytes and could shed light on how it persists effectively within the host, enduring unseen and escaping CD8+ T cell surveillance."
      explanation: Supports a causal link from MHC-I down-modulation to persistence and immune escape.
- name: Pro-inflammatory cytokine induction in epithelial and endothelial cells
  description: Brucella abortus RNA can increase IL-8 and IL-6 secretion in epithelial and endothelial cell models.
  cell_types:
  - preferred_term: epithelial cell
    term:
      id: CL:0000066
      label: epithelial cell
  - preferred_term: endothelial cell
    term:
      id: CL:0000115
      label: endothelial cell
  biological_processes:
  - preferred_term: regulation of cytokine production
    modifier: INCREASED
    term:
      id: GO:0001817
      label: regulation of cytokine production
  - preferred_term: inflammatory response
    modifier: INCREASED
    term:
      id: GO:0006954
      label: inflammatory response
  evidence:
  - reference: DOI:10.1371/journal.pone.0306429
    reference_title: "Beyond its preferential niche: Brucella abortus RNA down-modulates the IFN-γ-induced MHC-I expression in epithelial and endothelial cells"
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Contrary to our expectations, HMEC, Calu-6 and A-549 cells treated with Ba RNA had higher IL-8 and IL-6 levels compared to untreated cells."
    explanation: Supports cytokine induction in epithelial and endothelial cell lines after Brucella RNA exposure.
  downstream:
  - target: Fever
    description: Inflammatory cytokine signaling contributes to systemic febrile illness.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Given that 78% patients had fever, brucellosis poses a diagnostic challenge in malaria-endemic areas"
      explanation: Peer-reviewed systematic review quantifying fever (78%) as the dominant systemic manifestation, replacing a preprint citation.
- name: Persistent multisystem infection
  description: Brucellosis involves difficult-to-clear infection requiring prolonged combination therapy to clear infection and prevent relapse.
  biological_processes:
  - preferred_term: defense response to bacterium
    modifier: DYSREGULATED
    term:
      id: GO:0042742
      label: defense response to bacterium
  evidence:
  - reference: DOI:10.1038/s41598-024-69669-w
    reference_title: "A systematic review and meta-analysis of comparative clinical studies on antibiotic treatment of brucellosis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brucellosis is a difficult to treat infection that requires antibiotic combinations administered over several weeks for clearance of infection and relapse prevention."
    explanation: Supports persistent, relapse-prone infection as a clinical pathophysiology node.
  downstream:
  - target: Systemic constitutional illness
    description: Persistent systemic infection produces the characteristic constitutional and musculoskeletal symptom complex.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "arthralgia, myalgia and back pain affected around half of the patients (65%, 47% and 45%, respectively)"
      explanation: The systematic review identifies a coherent systemic symptom complex in human brucellosis.
  - target: Hematogenous dissemination
    description: Persistent infection enters the bloodstream and disseminates to distant tissues.
    evidence:
    - reference: DOI:10.1017/S0950268824000803
      reference_title: "National epidemiology of culture-confirmed brucellosis in Israel, 2004–2022"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Of 2,489 unique cases, 99.8% were bacteraemic"
      explanation: A national culture-confirmed cohort directly supports frequent bloodstream dissemination.
- name: Systemic constitutional illness
  description: Human brucellosis commonly manifests as a systemic febrile illness with fatigue, malaise, sweats, musculoskeletal pain, headache, and weight loss.
  biological_scale: ORGANISM
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "arthralgia, myalgia and back pain affected around half of the patients (65%, 47% and 45%, respectively)"
    explanation: Supports the systemic constitutional and musculoskeletal illness pattern in human brucellosis.
  downstream:
  - target: Fatigue
    description: Fatigue is a frequent constitutional manifestation of systemic brucellosis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Fatigue 2 19 (13; 23) 2 33 (13; 100) 5 51 (27; 75) 9 39 (16; 65)"
      explanation: The systematic review found fatigue in 39% of cases.
  - target: Joint pain
    description: Arthralgia is a frequent musculoskeletal manifestation of systemic brucellosis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "arthralgia, myalgia and back pain affected around half of the patients (65%, 47% and 45%, respectively)"
      explanation: The systematic review found arthralgia in 65% of cases.
  - target: Back pain
    description: Back pain is a common symptom in the general musculoskeletal complex and is not assumed to represent focal axial infection in every patient.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "arthralgia, myalgia and back pain affected around half of the patients (65%, 47% and 45%, respectively)"
      explanation: The meta-analysis places back pain in the common systemic musculoskeletal symptom complex.
  - target: Malaise
    description: Malaise is a frequent constitutional manifestation of systemic brucellosis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Malaise 2 24 (16; 34) 6 81 (71; 89) 8 74 (48; 93) 16 71 (57; 83)"
      explanation: The systematic review found malaise in 71% of cases.
  - target: Sweats
    description: Sweating is a frequent constitutional manifestation of systemic brucellosis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Sweats 8 23 (11; 37) 14 55 (35; 74) 12 73 (60; 85) 34 54 (42; 66)"
      explanation: The systematic review found sweats in 54% of cases.
  - target: Myalgia
    description: Myalgia is a frequent musculoskeletal manifestation of systemic brucellosis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Myalgia 2 18 (11; 26) 5 56 (38; 75) 8 49 (36; 63) 15 47 (38; 57)"
      explanation: The systematic review found myalgia in 47% of cases.
  - target: Headache
    description: Headache is a frequent constitutional manifestation of systemic brucellosis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Headache 6 9 (5; 15) 11 34 (19; 50) 11 52 (32; 72) 28 35 (24; 46)"
      explanation: The systematic review found headache in 35% of cases.
  - target: Weight loss
    description: Weight loss accompanies the systemic illness of brucellosis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Weight loss 3 13(8;18) 4 31 (15; 50) 7 29 (15; 47) 14 26 (17; 36)"
      explanation: The systematic review found weight loss in 26% of cases.
- name: Hematogenous dissemination
  description: Brucella bacteraemia distributes organisms from the persistent systemic reservoir to distant tissues.
  biological_scale: ORGANISM
  evidence:
  - reference: DOI:10.1017/S0950268824000803
    reference_title: "National epidemiology of culture-confirmed brucellosis in Israel, 2004–2022"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Of 2,489 unique cases, 99.8% were bacteraemic"
    explanation: A national culture-confirmed cohort documents near-universal bloodstream involvement.
  downstream:
  - target: Osteoarticular seeding
    description: Bloodstream dissemination permits focal infection of joints, sacroiliac joints, and vertebral structures.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Arthralgia was common, affecting 65% patients overall, whereas arthritis affected only 26% patients"
      explanation: The meta-analysis supports focal arthritis after dissemination; it does not directly observe the seeding event.
  - target: Cardiac valve seeding
    description: Bloodstream organisms can establish focal valvular infection.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Severe complications of brucellosis infection were not rare, with 1 case of endocarditis and 4 neurological cases per 100 patients"
      explanation: The review supports endocarditis as a focal complication but does not directly observe valvular seeding.
  - target: Central nervous system invasion
    description: Bloodstream dissemination can lead to focal neurologic infection.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Severe complications of brucellosis infection were not rare, with 1 case of endocarditis and 4 neurological cases per 100 patients"
      explanation: The review supports neurologic focal disease but not the precise route of CNS entry.
  - target: Genitourinary seeding
    description: Bloodstream dissemination can establish focal infection in the epididymis and testis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "One in 10 men experienced epididymo-orchitis, the most common genitourinary complication of brucellosis infection"
      explanation: The meta-analysis supports focal genitourinary infection; hematogenous seeding is inferred.
  - target: Placental infection
    description: Maternal infection can involve the placenta and threaten pregnancy.
    evidence:
    - reference: DOI:10.1186/s43088-024-00569-8
      reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
      explanation: The review supports pregnancy complications; placental localization is an inferred intermediate.
  - target: Reticuloendothelial organ seeding
    description: Bloodstream organisms can localize in liver and spleen.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Hepatomegaly 10 27 (15; 41) 13 22 (16; 26) 14 22 (15; 29) 37 23 (19; 27)"
      explanation: Liver enlargement supports reticuloendothelial involvement, while the seeding route remains inferred.
  - target: Abdominal organ involvement
    description: Disseminated brucellosis can involve abdominal organs and produce abdominal pain.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Abdominal pain 3 14 (1; 38) 4 9 (1; 22) 9 26 (13; 41) 16 19 (11; 29)"
      explanation: The symptom frequency supports abdominal involvement but does not localize a single organ.
- name: Osteoarticular seeding
  description: Focal osteoarticular infection affects peripheral joints, sacroiliac joints, or vertebral structures.
  biological_scale: ORGANISM
  downstream:
  - target: Arthritis
    description: Peripheral joint infection may manifest as arthritis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Arthralgia was common, affecting 65% patients overall, whereas arthritis affected only 26% patients"
      explanation: The systematic review found arthritis in 26% of cases.
  - target: Sacroiliitis
    description: Sacroiliac focal infection manifests as sacroiliitis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Overall, spondylitis and sacroiliitis were detected in 12–36% adults"
      explanation: The systematic review documents sacroiliitis as an adult focal manifestation.
  - target: Spondylitis
    description: Vertebral focal infection manifests as spondylitis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Spondylitis 1 18 (1; 28)* 6 12 (7, 19) 9 11 (6; 18) 16 12 (8; 17)"
      explanation: The systematic review found spondylitis in 12% of cases.
- name: Cardiac valve seeding
  description: Focal Brucella infection of cardiac valves produces endocarditis.
  biological_scale: ORGANISM
  downstream:
  - target: Endocarditis
    description: Valvular infection manifests as endocarditis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Severe complications of brucellosis infection were not rare, with 1 case of endocarditis and 4 neurological cases per 100 patients"
      explanation: The systematic review documents endocarditis in approximately 1% of cases.
- name: Central nervous system invasion
  description: Focal neurologic infection produces neurobrucellosis.
  biological_scale: ORGANISM
  downstream:
  - target: Neurobrucellosis
    description: CNS involvement may manifest as meningitis or meningoencephalitis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Neurological 5 2 (1; 4) 11 5 (3; 7) 10 4 (2; 6) 26 4 (3; 5)"
      explanation: The systematic review found neurologic involvement in 4% of cases.
- name: Genitourinary seeding
  description: Focal genitourinary infection affects the epididymis and testis.
  biological_scale: ORGANISM
  downstream:
  - target: Epididymo-orchitis
    description: Epididymal and testicular infection manifests as epididymo-orchitis.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "One in 10 men experienced epididymo-orchitis, the most common genitourinary complication of brucellosis infection"
      explanation: The systematic review documents epididymo-orchitis in approximately 10% of male cases.
- name: Placental infection
  description: Maternal brucellosis can compromise pregnancy through placental involvement.
  biological_scale: ORGANISM
  downstream:
  - target: Miscarriage
    description: Maternal infection may result in miscarriage.
    evidence:
    - reference: DOI:10.1186/s43088-024-00569-8
      reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
      explanation: The scoping review documents miscarriage among maternal-fetal complications.
  - target: Premature birth
    description: Maternal infection may result in premature birth.
    evidence:
    - reference: DOI:10.1186/s43088-024-00569-8
      reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
      explanation: The scoping review documents premature birth among maternal-fetal complications.
- name: Reticuloendothelial organ seeding
  description: Focal infection of liver and spleen produces organ enlargement.
  biological_scale: ORGANISM
  downstream:
  - target: Hepatosplenomegaly
    description: Combined liver and spleen enlargement is documented in maternal-child brucellosis.
    evidence:
    - reference: DOI:10.1186/s43088-024-00569-8
      reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
      explanation: The combined finding is scoped to the maternal-child review.
  - target: Splenomegaly
    description: Splenic involvement manifests as splenomegaly.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Splenomegaly 9 31 (19; 43) 13 24 (18; 31) 14 25 (17; 34) 36 26 (21; 31)"
      explanation: The systematic review found splenomegaly in 26% of cases.
  - target: Hepatomegaly
    description: Hepatic involvement manifests as hepatomegaly.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Hepatomegaly 10 27 (15; 41) 13 22 (16; 26) 14 22 (15; 29) 37 23 (19; 27)"
      explanation: The systematic review found hepatomegaly in 23% of cases.
- name: Abdominal organ involvement
  description: Disseminated abdominal involvement produces abdominal pain.
  biological_scale: ORGANISM
  downstream:
  - target: Abdominal pain
    description: Abdominal involvement manifests as abdominal pain.
    evidence:
    - reference: PMID:23236528
      reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Abdominal pain 3 14 (1; 38) 4 9 (1; 22) 9 26 (13; 41) 16 19 (11; 29)"
      explanation: The systematic review found abdominal pain in 19% of cases.
- name: Facultative Intracellular Niche (Cell-Penetrant Drug Requirement)
  description: >-
    Brucella is a facultative intracellular pathogen that survives and replicates
    within host phagocytes (chiefly macrophages). This intracellular lifestyle
    shields the organism from antibodies and complement and, critically for
    therapy, from antibiotics that cannot accumulate inside eukaryotic cells —
    notably the beta-lactams. Effective treatment is therefore restricted to
    cell-penetrant agents (doxycycline, aminoglycosides that concentrate at the
    site, rifampicin), and cure requires prolonged combination therapy to reach
    and clear the protected intracellular reservoir. This is the lifestyle-gating
    principle that constrains drug choice beyond any single molecular target.
  role: intrinsic_resistance
  conforms_to: "intracellular_pathogen_persistence#Intracellular Niche and Beta-Lactam Exclusion"
  cell_types:
  - preferred_term: macrophage
    term:
      id: CL:0000235
      label: macrophage
  biological_processes:
  - preferred_term: Biological Process Involved in Interaction with Host
    term:
      id: GO:0051701
      label: biological process involved in interaction with host
  evidence:
  - reference: DOI:10.1371/journal.pone.0306429
    reference_title: "Beyond its preferential niche: Brucella abortus RNA down-modulates the IFN-γ-induced MHC-I expression in epithelial and endothelial cells"
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: "Brucella abortus (Ba) is a pathogen that survives inside macrophages."
    explanation: Supports the facultative intracellular (macrophage-resident) niche that underlies the cell-penetrant-drug requirement.
  - reference: PMID:18611821
    reference_title: "Intracellular organisms."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      The intracellular location of some microorganisms allow them to resist
      antibiotics with poor ability to penetrate eukaryotic cell membranes, such
      as the beta-lactam compounds.
    explanation: >-
      Review establishing that the intracellular niche confers resistance to
      poorly cell-penetrant antibiotics such as beta-lactams, the gating
      principle this node represents. Evidence source is OTHER as this is a
      review article.
  downstream:
  - target: Requirement for Cell-Penetrant Antimicrobials
    description: >-
      Because the intracellular niche excludes poorly penetrant drugs, effective
      brucellosis therapy is restricted to agents that accumulate inside host
      cells.
    evidence:
    - reference: PMID:18611821
      reference_title: "Intracellular organisms."
      supports: SUPPORT
      evidence_source: OTHER
      snippet: >-
        The intracellular location of some microorganisms allow them to resist
        antibiotics with poor ability to penetrate eukaryotic cell membranes,
        such as the beta-lactam compounds.
      explanation: The intracellular niche directly creates the requirement for antimicrobials that penetrate host cells.
- name: Requirement for Cell-Penetrant Antimicrobials
  description: >-
    Efficacy against the intracellular Brucella reservoir tracks the intracellular
    concentration a drug achieves, not merely its in vitro MIC. Doxycycline,
    rifampicin, and aminoglycosides accumulate within (or otherwise reach)
    infected cells, whereas beta-lactams do not — so the mainstay regimens are
    built from cell-penetrant agents given in prolonged combination. This is the
    cell-penetrant-drug requirement that the brucellosis treatments target.
  role: therapeutic_vulnerability
  conforms_to: "intracellular_pathogen_persistence#Requirement for Cell-Penetrant Antimicrobials"
  biological_processes:
  - preferred_term: Response to Antibiotic
    term:
      id: GO:0046677
      label: response to antibiotic
  evidence:
  - reference: PMID:28639230
    reference_title: "Intracellular Pharmacokinetics of Antibacterials and Their Clinical Implications."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      Therapeutic efficacy against intracellular pathogens has been correlated
      mainly with the intracellular concentrations achieved by the different
      antimicrobial agents.
    explanation: >-
      Review establishing that efficacy against intracellular pathogens depends
      on the intracellular concentration achieved — the cell-penetrant
      requirement this node represents. Evidence source is OTHER as this is a
      review article.
- name: Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target)
  description: >-
    Brucella, like other bacteria, depends on 70S-ribosome translation of its
    mRNA. Doxycycline (a tetracycline) binds the 30S subunit and blocks
    aminoacyl-tRNA delivery, and the aminoglycosides streptomycin and gentamicin
    also target the 30S ribosome — the shared molecular target that anchors the
    doxycycline-plus-aminoglycoside brucellosis regimens. This is a bacterial
    target absent from the beta-lactam-inaccessible host cytoplasm, complementing
    the intracellular-niche gating node.
  role: therapeutic_vulnerability
  conforms_to: "bacterial_protein_synthesis_inhibition#Bacterial mRNA Translation by the Ribosome"
  biological_processes:
  - preferred_term: Translation
    term:
      id: GO:0006412
      label: translation
  evidence:
  - reference: PMID:24336183
    reference_title: "Ribosome-targeting antibiotics and mechanisms of bacterial resistance."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      The ribosome is one of the main antibiotic targets in the bacterial cell.
    explanation: >-
      Review establishing the bacterial ribosome as the target of tetracyclines
      and aminoglycosides, the protein-synthesis-inhibition step this node
      represents. Evidence source is OTHER as this is a review article.
- name: Bacterial RNA Polymerase (Rifamycin Target)
  description: >-
    Rifampicin, a component of the classic WHO-recommended doxycycline-rifampicin
    regimen, binds the beta subunit of bacterial DNA-dependent RNA polymerase and
    blocks nascent-transcript elongation. Because rifamycins are cell- and
    tissue-penetrant, this target is reachable in the intracellular Brucella
    reservoir; single rpoB point mutations confer high-level resistance, which is
    part of why rifampicin is used in combination rather than alone.
  role: therapeutic_vulnerability
  conforms_to: "bacterial_rna_polymerase_inhibition#Bacterial RNA Polymerase (Rifamycin Target)"
  biological_processes:
  - preferred_term: DNA-Templated Transcription
    term:
      id: GO:0006351
      label: DNA-templated transcription
  evidence:
  - reference: PMID:32342856
    reference_title: "Inhibition of RNA Polymerase by Rifampicin and Rifamycin-Like Molecules."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: >-
      The most clinically important and extensively studied class of antibiotics
      known to inhibit bacterial RNAP are the rifamycins.
    explanation: >-
      Review establishing bacterial RNA polymerase as the rifamycin target, the
      transcription-inhibition step this node represents. Evidence source is
      OTHER as this is a review article.
phenotypes:
- category: Clinical
  name: Fever
  description: Fever is the dominant non-specific manifestation of human brucellosis.
  phenotype_term:
    preferred_term: Fever
    term:
      id: HP:0001945
      label: Fever
  frequency: FREQUENT
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Given that 78% patients had fever, brucellosis poses a diagnostic challenge in malaria-endemic areas"
    explanation: Peer-reviewed systematic review; pooled 78% of cases had fever, supporting a FREQUENT (30-79%) band and replacing a preprint citation.
- category: Clinical
  name: Fatigue
  description: Fatigue is part of the non-specific systemic presentation.
  phenotype_term:
    preferred_term: Fatigue
    term:
      id: HP:0012378
      label: Fatigue
  frequency: FREQUENT
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Fatigue 2 19 (13; 23) 2 33 (13; 100) 5 51 (27; 75) 9 39 (16; 65)"
    explanation: Peer-reviewed systematic review Table 2; fatigue in 39% of cases (all ages), supporting a FREQUENT band and replacing a preprint citation.
- category: Clinical
  name: Joint pain
  description: Joint pain is a common non-specific musculoskeletal manifestation.
  phenotype_term:
    preferred_term: Joint pain
    term:
      id: HP:0002829
      label: Arthralgia
  frequency: FREQUENT
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "arthralgia, myalgia and back pain affected around half of the patients (65%, 47% and 45%, respectively)"
    explanation: Peer-reviewed systematic review; arthralgia affected 65% of cases, supporting a FREQUENT (30-79%) band and replacing a preprint citation.
- category: Clinical
  name: Endocarditis
  description: Endocarditis is a rare but serious focal complication and the leading cause of brucellosis-related death.
  phenotype_term:
    preferred_term: Endocarditis
    term:
      id: HP:0100584
      label: Endocarditis
  frequency: VERY_RARE
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Severe complications of brucellosis infection were not rare, with 1 case of endocarditis and 4 neurological cases per 100 patients"
    explanation: Peer-reviewed systematic review; endocarditis occurred in ~1 per 100 cases, supporting a VERY_RARE (<5%) band and replacing a preprint citation.
- category: Clinical
  name: Arthritis
  description: Arthritis is a focal musculoskeletal complication of brucellosis.
  phenotype_term:
    preferred_term: Arthritis
    term:
      id: HP:0001369
      label: Arthritis
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Arthralgia was common, affecting 65% patients overall, whereas arthritis affected only 26% patients"
    explanation: Peer-reviewed systematic review; frank arthritis affected 26% of cases overall, supporting an OCCASIONAL band and replacing a methods-list quote.
- category: Clinical
  name: Sacroiliitis
  description: >-
    Sacroiliitis and spondylitis are the characteristic osteoarticular focal
    manifestations of brucellosis, reflecting the organism's tropism for the
    axial skeleton.
  phenotype_term:
    preferred_term: Sacroiliitis
    term:
      id: HP:0012317
      label: Sacroiliac arthritis
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Overall, spondylitis and sacroiliitis were detected in 12–36% adults"
    explanation: Peer-reviewed systematic review; osteoarticular focal disease (spondylitis/sacroiliitis) detected in 12–36% of adults, supporting an OCCASIONAL band.
- category: Clinical
  name: Epididymo-orchitis
  description: >-
    Epididymo-orchitis is the most common genitourinary focal complication in
    men with brucellosis (roughly 1 in 10 male cases). The ontology term Orchitis
    is the closest available match for the epididymo-orchitis presentation.
  phenotype_term:
    preferred_term: Epididymo-orchitis
    term:
      id: HP:0100796
      label: Orchitis
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "One in 10 men experienced epididymo-orchitis, the most common genitourinary complication of brucellosis infection"
    explanation: Peer-reviewed systematic review; epididymo-orchitis in ~10% of male cases (OCCASIONAL band, male denominator) and the most common genitourinary complication.
- category: Clinical
  name: Miscarriage
  description: Miscarriage is a documented adverse pregnancy outcome of maternal brucellosis.
  notes: >-
    No phenotype term is assigned because the available miscarriage terms are
    not currently reachable from the disease-entry phenotype root used by this schema.
  frequency: OCCASIONAL
  evidence:
  - reference: DOI:10.1186/s43088-024-00569-8
    reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
    explanation: The scoping review documents miscarriage in 25% of the maternal brucellosis literature summarized, supporting an OCCASIONAL band.
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "only one study reported abortion rates as a proportion of pregnant female participants, which was 46%"
    explanation: >-
      A single contributing study supplies additional pregnancy-specific
      evidence but is not used to replace the broader 25% frequency estimate.
- category: Clinical
  name: Premature birth
  description: Premature birth is a documented adverse pregnancy outcome of maternal brucellosis.
  phenotype_term:
    preferred_term: Premature birth
    term:
      id: HP:0001622
      label: Premature birth
  frequency: OCCASIONAL
  evidence:
  - reference: DOI:10.1186/s43088-024-00569-8
    reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
    explanation: The scoping review documents preterm birth in 20% of the maternal brucellosis literature summarized, supporting an OCCASIONAL band.
- category: Clinical
  name: Hepatosplenomegaly
  description: Hepatosplenomegaly is documented among maternal-child brucellosis complications.
  phenotype_term:
    preferred_term: Hepatosplenomegaly
    term:
      id: HP:0001433
      label: Hepatosplenomegaly
  evidence:
  - reference: DOI:10.1186/s43088-024-00569-8
    reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Substantial risks of miscarriage (25%), preterm birth (20%), hepatosplenomegaly (10%), febrile illness (30%), and possible long-term complications were documented."
    explanation: Supports hepatosplenomegaly as a documented complication in maternal-child brucellosis literature.
- category: Clinical
  name: Malaise
  description: Malaise is a frequent constitutional symptom of brucellosis.
  phenotype_term:
    preferred_term: Malaise
    term:
      id: HP:0033834
      label: Malaise
  frequency: FREQUENT
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Malaise 2 24 (16; 34) 6 81 (71; 89) 8 74 (48; 93) 16 71 (57; 83)"
    explanation: Peer-reviewed systematic review Table 2; malaise in 71% of cases (all ages), a FREQUENT band.
- category: Clinical
  name: Sweats
  description: Profuse sweating is a classic constitutional feature of brucellosis (historically "undulant fever" with drenching sweats).
  phenotype_term:
    preferred_term: Sweats
    term:
      id: HP:0000975
      label: Hyperhidrosis
  frequency: FREQUENT
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Sweats 8 23 (11; 37) 14 55 (35; 74) 12 73 (60; 85) 34 54 (42; 66)"
    explanation: Peer-reviewed systematic review Table 2; sweats in 54% of cases (all ages), a FREQUENT band.
- category: Clinical
  name: Myalgia
  description: Myalgia is a frequent musculoskeletal symptom of brucellosis.
  phenotype_term:
    preferred_term: Myalgia
    term:
      id: HP:0003326
      label: Myalgia
  frequency: FREQUENT
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Myalgia 2 18 (11; 26) 5 56 (38; 75) 8 49 (36; 63) 15 47 (38; 57)"
    explanation: Peer-reviewed systematic review Table 2; myalgia in 47% of cases (all ages), a FREQUENT band.
- category: Clinical
  name: Back pain
  description: Back pain is a frequent axial-musculoskeletal symptom of brucellosis.
  phenotype_term:
    preferred_term: Back pain
    term:
      id: HP:0003418
      label: Back pain
  frequency: FREQUENT
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Back pain 1 10 (3; 21)* 11 49 (31; 67) 11 45 (31; 60) 23 45 (34; 56)"
    explanation: Peer-reviewed systematic review Table 2; back pain in 45% of cases (all ages), a FREQUENT band.
- category: Clinical
  name: Headache
  description: Headache is a frequent constitutional symptom of brucellosis.
  phenotype_term:
    preferred_term: Headache
    term:
      id: HP:0002315
      label: Headache
  frequency: FREQUENT
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Headache 6 9 (5; 15) 11 34 (19; 50) 11 52 (32; 72) 28 35 (24; 46)"
    explanation: Peer-reviewed systematic review Table 2; headache in 35% of cases (all ages), a FREQUENT band.
- category: Clinical
  name: Splenomegaly
  description: Splenomegaly is a common organ finding in systemic brucellosis.
  phenotype_term:
    preferred_term: Splenomegaly
    term:
      id: HP:0001744
      label: Splenomegaly
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Splenomegaly 9 31 (19; 43) 13 24 (18; 31) 14 25 (17; 34) 36 26 (21; 31)"
    explanation: Peer-reviewed systematic review Table 2; splenomegaly in 26% of cases (all ages), an OCCASIONAL band.
- category: Clinical
  name: Hepatomegaly
  description: Hepatomegaly is a common organ finding in systemic brucellosis.
  phenotype_term:
    preferred_term: Hepatomegaly
    term:
      id: HP:0002240
      label: Hepatomegaly
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Hepatomegaly 10 27 (15; 41) 13 22 (16; 26) 14 22 (15; 29) 37 23 (19; 27)"
    explanation: Peer-reviewed systematic review Table 2; hepatomegaly in 23% of cases (all ages), an OCCASIONAL band.
- category: Clinical
  name: Weight loss
  description: Weight loss accompanies the chronic constitutional illness of brucellosis.
  phenotype_term:
    preferred_term: Weight loss
    term:
      id: HP:0001824
      label: Weight loss
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Weight loss 3 13(8;18) 4 31 (15; 50) 7 29 (15; 47) 14 26 (17; 36)"
    explanation: Peer-reviewed systematic review Table 2; weight loss in 26% of cases (all ages), an OCCASIONAL band.
- category: Clinical
  name: Abdominal pain
  description: Abdominal pain is a recognized abdominal manifestation of brucellosis.
  phenotype_term:
    preferred_term: Abdominal pain
    term:
      id: HP:0002027
      label: Abdominal pain
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Abdominal pain 3 14 (1; 38) 4 9 (1; 22) 9 26 (13; 41) 16 19 (11; 29)"
    explanation: Peer-reviewed systematic review Table 2; abdominal pain in 19% of cases (all ages), an OCCASIONAL band.
- category: Clinical
  name: Spondylitis
  description: >-
    Spondylitis (with sacroiliitis) is a characteristic osteoarticular focal
    manifestation of brucellosis affecting the axial skeleton.
  phenotype_term:
    preferred_term: Spondylitis
    term:
      id: HP:0033631
      label: Spondylitis
  frequency: OCCASIONAL
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Spondylitis 1 18 (1; 28)* 6 12 (7, 19) 9 11 (6; 18) 16 12 (8; 17)"
    explanation: Peer-reviewed systematic review Table 2; spondylitis in 12% of cases (all ages), an OCCASIONAL band.
- category: Clinical
  name: Neurobrucellosis
  description: >-
    Neurobrucellosis — central nervous system involvement, most commonly
    presenting as meningitis or meningoencephalitis — is an uncommon but serious
    focal complication. The ontology term Meningitis is used as the closest
    representative of this CNS syndrome.
  phenotype_term:
    preferred_term: Neurobrucellosis
    term:
      id: HP:0001287
      label: Meningitis
  frequency: VERY_RARE
  evidence:
  - reference: PMID:23236528
    reference_title: "Clinical manifestations of human brucellosis: a systematic review and meta-analysis."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Neurological 5 2 (1; 4) 11 5 (3; 7) 10 4 (2; 6) 26 4 (3; 5)"
    explanation: Peer-reviewed systematic review Table 2; neurological (neurobrucellosis) involvement in 4% of cases (all ages), a VERY_RARE band.
environmental:
- name: Livestock-dependent setting
  presence: risk factor
  description: Livestock-dependent regions have higher exposure opportunity for zoonotic Brucella transmission.
  influences_mechanisms:
  - target: Zoonotic acquisition and inoculation
    environmental_effect: PREDISPOSES
    causal_link_type: INDIRECT_KNOWN_INTERMEDIATES
    description: >-
      A livestock-dependent economy is a determinant of how much contact a population
      has with the animal reservoir, not an exposure in itself. Proximity to infected
      animals and consumption of unpasteurized local dairy are the known intervening
      steps, and neither is a node in this graph.
    evidence:
    - reference: PMID:37630630
      reference_title: "Brucellosis and One Health: Inherited and Future Challenges"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "focused on high-risk groups (animal and human health workers, livestock owners, dairy farmers, abattoir workers, pastoralists, patients, students and residents"
      explanation: >-
        A 79-study, 22-country review whose high-risk groups are named as livestock
        owners, dairy farmers, abattoir workers and pastoralists - occupations defined
        by livestock dependence rather than by geography, which is what this link
        asserts the setting concentrates.
  evidence:
  - reference: PMID:37630630
    reference_title: "Brucellosis and One Health: Inherited and Future Challenges"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "brucellosis is considered a severe problem in animals and humans in Asia, the Middle East, Africa and Ibero-America"
    explanation: >-
      Peer-reviewed support for the geographic concentration of brucellosis in the
      regions where livestock husbandry is economically dominant.
  - reference: DOI:10.21203/rs.3.rs-4929733/v1
    reference_title: "Global prevalence of human brucellosis: A systematic review and meta-analysis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Human brucellosis caused by various Brucella species is a significant global health concern, particularly in livestock-dependent regions."
    explanation: >-
      Names livestock-dependent regions directly, which no peer-reviewed source cited
      here does in those words. Downgraded from SUPPORT to PARTIAL because this is a
      Research Square preprint that has not been peer reviewed; it is retained as
      corroboration rather than as the item the claim rests on.
  notes: >-
    Issue #8302 asked for an explicit decision on the Research Square preprint cited
    here rather than letting it stand by default. Decision: keep it, demoted to
    PARTIAL and no longer the primary support, with the peer-reviewed One Health
    review (PMID:37630630) carrying the claim. Its snippet does verify against the
    cached document; the objection was to its epistemic status, not its accuracy.
- name: Maternal livestock exposure
  presence: risk factor
  exposure_term:
    preferred_term: exposure to livestock
    term:
      id: ECTO:3000000
      label: exposure to organism
  influences_mechanisms:
  - target: Zoonotic acquisition and inoculation
    environmental_effect: TRIGGERS
    causal_link_type: DIRECT
    description: >-
      Unlike the setting-level entry above, this is the exposure event itself: contact
      with infected livestock is how the organism reaches the host in this group, and
      the cited review puts the majority of cases on that route.
    evidence:
    - reference: DOI:10.1186/s43088-024-00569-8
      reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Key findings demonstrate that zoonotic brucellosis acquisition from livestock exposures among vulnerable maternal groups accounts for up to 70% of cases."
      explanation: >-
        Quantifies livestock exposure as the dominant acquisition route in this group,
        which is exactly the node this link targets.
  notes: >-
    Bound to ECTO:3000000 exposure to organism, the most specific applicable ECTO term
    - ECTO has no Brucella, livestock, or raw-milk exposure class (searched
    2026-08-25). Same fallback pattern as the viral exposures bound to ECTO:3000001.
    This reference has no PMID: the Beni-Suef University Journal of Basic and Applied
    Sciences is not PubMed-indexed, so unlike the other two exposures here it cannot
    be moved off a DOI and remains unchecked by linkml-reference-validator. Its
    snippet was verified by hand against the cached document.
  evidence:
  - reference: DOI:10.1186/s43088-024-00569-8
    reference_title: "Exploring the impact of brucellosis on maternal and child health: transmission mechanisms, patient effects, and current trends in drug use and resistance: a scoping review"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Key findings demonstrate that zoonotic brucellosis acquisition from livestock exposures among vulnerable maternal groups accounts for up to 70% of cases."
    explanation: Supports livestock exposure as a maternal risk context.
- name: Inadequate One Health control infrastructure
  presence: risk factor
  description: Weak surveillance, diagnostic, veterinary, and public-health infrastructure can impair brucellosis control in endemic settings.
  influences_mechanisms:
  - target: Zoonotic acquisition and inoculation
    environmental_effect: PREDISPOSES
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Control infrastructure acts on the animal reservoir rather than on the person:
      weak veterinary surveillance, absent herd vaccination and unenforced milk
      pasteurization all leave more infected animals and products in contact with
      people. The review documents the infrastructural weakness but does not trace it
      through to a case count, so the intermediates are recorded as unknown.
    evidence:
    - reference: PMID:37630630
      reference_title: "Brucellosis and One Health: Inherited and Future Challenges"
      supports: SUPPORT
      evidence_source: OTHER
      snippet: "Extended infrastructural weaknesses, often accentuated by geography and climate, are critically important."
      explanation: >-
        Names infrastructural weakness as critically important to brucellosis control.
        PARTIAL because the review argues its importance for control rather than
        measuring an effect on acquisition, which is what this link asserts.
  notes: >-
    Left unbound: this is a health-system determinant rather than an exposure, and
    ECTO has no class for control or surveillance infrastructure (searched
    2026-08-25). Citations moved from DOI:10.3390/microorganisms11082070 to
    PMID:37630630, the same paper, so that linkml-reference-validator now checks these
    snippets instead of skipping them on the DOI prefix.
  evidence:
  - reference: PMID:37630630
    reference_title: "Brucellosis and One Health: Inherited and Future Challenges"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Brucellosis One Health actors include Public Health and Veterinary Services, microbiologists, medical and veterinary practitioners and breeders."
    explanation: Supports multidisciplinary One Health control context.
  - reference: PMID:37630630
    reference_title: "Brucellosis and One Health: Inherited and Future Challenges"
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "Extended infrastructural weaknesses, often accentuated by geography and climate, are critically important."
    explanation: Supports infrastructure as a risk modifier for brucellosis control.
treatments:
- name: Doxycycline-rifampicin combination therapy
  description: Standard oral dual antibiotic therapy used for uncomplicated human brucellosis and bacteremic disease, though relapse risk can be higher than with some aminoglycoside-containing regimens.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: doxycycline
      term:
        id: CHEBI:50845
        label: doxycycline
    - preferred_term: rifampicin
      term:
        id: CHEBI:28077
        label: rifampicin
  target_mechanisms:
  - target: Persistent multisystem infection
    treatment_effect: INHIBITS
    description: Combination antibiotic therapy targets clearance of persistent infection and prevention of relapse.
    evidence:
    - reference: DOI:10.1038/s41598-024-69669-w
      reference_title: "A systematic review and meta-analysis of comparative clinical studies on antibiotic treatment of brucellosis"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Brucellosis is a difficult to treat infection that requires antibiotic combinations administered over several weeks for clearance of infection and relapse prevention."
      explanation: Supports using prolonged combination therapy to clear infection and reduce relapse.
  - target: Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target)
    treatment_effect: INHIBITS
    description: Doxycycline binds the 30S ribosome and arrests bacterial protein synthesis.
  - target: Bacterial RNA Polymerase (Rifamycin Target)
    treatment_effect: INHIBITS
    description: Rifampicin binds bacterial RNA polymerase and blocks transcription.
  - target: Requirement for Cell-Penetrant Antimicrobials
    treatment_effect: INHIBITS
    description: >-
      Both agents are cell-penetrant and so reach the intracellular Brucella
      reservoir that beta-lactams cannot.
  evidence:
  - reference: DOI:10.1038/s41598-024-69669-w
    reference_title: "A systematic review and meta-analysis of comparative clinical studies on antibiotic treatment of brucellosis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "However, the latter is also efficacious and suitable for uncomplicated disease."
    explanation: In context, supports doxycycline-rifampicin as an efficacious uncomplicated-disease option despite better outcomes for some triple therapies.
  - reference: DOI:10.37723/jumdc.v15i3.920
    reference_title: "Response of the intravenous versus oral antibiotic regimen in brucellosis bacteremia."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "CONCLUSION: Oral doxycycline-rifampicin (DR) and IV gentamicin-doxycycline-rifampicin (GDR) regimens have similar response rates in bacteremia brucellosis."
    explanation: Supports oral doxycycline-rifampicin as a bacteremic brucellosis regimen in an observational comparison.
- name: Doxycycline-streptomycin combination therapy
  description: Aminoglycoside-containing combination therapy with evidence of superior efficacy compared with doxycycline-rifampicin in network meta-analyses.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: doxycycline
      term:
        id: CHEBI:50845
        label: doxycycline
    - preferred_term: streptomycin
      term:
        id: CHEBI:17076
        label: streptomycin
  target_mechanisms:
  - target: Persistent multisystem infection
    treatment_effect: INHIBITS
    description: Aminoglycoside-containing doxycycline therapy is used to improve clearance and reduce relapse risk.
    evidence:
    - reference: DOI:10.1371/journal.pntd.0012010
      reference_title: "Efficacy and safety of therapeutic strategies for human brucellosis: A systematic review and network meta-analysis"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "This review confirmed the superiority of drugs already indicated for treating human brucellosis, such as the combination of doxycycline and aminoglycosides."
      explanation: Supports an aminoglycoside-containing doxycycline regimen as a superior brucellosis treatment strategy.
  - target: Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target)
    treatment_effect: INHIBITS
    description: Both doxycycline and streptomycin bind the 30S ribosome and arrest bacterial protein synthesis.
  - target: Requirement for Cell-Penetrant Antimicrobials
    treatment_effect: INHIBITS
    description: Doxycycline reaches the intracellular reservoir; the aminoglycoside adds bactericidal activity for prolonged-course cure.
  evidence:
  - reference: DOI:10.1371/journal.pntd.0012405
    reference_title: "Updated therapeutic options for human brucellosis: A systematic review and network meta-analysis of randomized controlled trials"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Brucellosis medications differ in efficacy and safety. Doxycycline + Gentamicin, Triple, and Doxycycline + Streptomycin have superior efficacy and safety."
    explanation: Supports doxycycline-streptomycin as a high-performing regimen class.
  - reference: DOI:10.1038/s41598-024-69669-w
    reference_title: "A systematic review and meta-analysis of comparative clinical studies on antibiotic treatment of brucellosis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Triple antibiotic therapy is more effective than standard dual therapy with rifampicin and doxycycline."
    explanation: Supports intensifying beyond standard dual therapy for improved treatment outcomes.
- name: Doxycycline-gentamicin combination therapy
  description: >-
    Aminoglycoside-containing combination therapy that ranked highest for efficacy
    (SUCRA 0.94) in a 2024 network meta-analysis of randomized trials. Scope
    caveat: that meta-analysis restricted inclusion to trials of children and
    adolescents (pooled trial population aged 13-70), the doxycycline-gentamicin
    top ranking rested on only 2 trials, and the authors state their
    recommendations are not applicable to young children (<8 years), pregnant
    women, or focal disease such as spondylitis, endocarditis, and
    neurobrucellosis.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: doxycycline
      term:
        id: CHEBI:50845
        label: doxycycline
    - preferred_term: gentamicin
      term:
        id: CHEBI:17833
        label: gentamycin
  target_mechanisms:
  - target: Persistent multisystem infection
    treatment_effect: INHIBITS
    description: Doxycycline-gentamicin therapy is used to improve infection clearance and prevent treatment failure.
    evidence:
    - reference: DOI:10.1371/journal.pntd.0012405
      reference_title: "Updated therapeutic options for human brucellosis: A systematic review and network meta-analysis of randomized controlled trials"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "Doxycycline + Gentamicin ranked the best in efficacy (SUCRA values: 0.94), the second is Triple (SUCRA values: 0.87), and the third is Doxycycline + Streptomycin (SUCRA values: 0.78)."
      explanation: Supports doxycycline-gentamicin as the top-ranked efficacy regimen in the network meta-analysis, whose inclusion was restricted to children/adolescents and rested on only 2 gentamicin-arm trials.
  - target: Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target)
    treatment_effect: INHIBITS
    description: Both doxycycline and gentamicin bind the 30S ribosome and arrest bacterial protein synthesis.
  - target: Requirement for Cell-Penetrant Antimicrobials
    treatment_effect: INHIBITS
    description: Doxycycline reaches the intracellular reservoir; gentamicin adds bactericidal activity during the initial course.
  evidence:
  - reference: DOI:10.1371/journal.pntd.0012405
    reference_title: "Updated therapeutic options for human brucellosis: A systematic review and network meta-analysis of randomized controlled trials"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Doxycycline + Gentamicin ranked the best in efficacy (SUCRA values: 0.94), the second is Triple (SUCRA values: 0.87), and the third is Doxycycline + Streptomycin (SUCRA values: 0.78)."
    explanation: Supports doxycycline-gentamicin as a high-efficacy brucellosis regimen; the network meta-analysis restricted inclusion to children/adolescents and the gentamicin arm comprised only 2 trials.
- name: Doxycycline-streptomycin-hydroxychloroquine triple therapy
  description: Emerging triple therapy identified as a potential strategy to reduce overall therapy failure, with very low-certainty evidence requiring confirmation.
  treatment_term:
    preferred_term: Pharmacotherapy
    term:
      id: NCIT:C15986
      label: Pharmacotherapy
    therapeutic_agent:
    - preferred_term: doxycycline
      term:
        id: CHEBI:50845
        label: doxycycline
    - preferred_term: streptomycin
      term:
        id: CHEBI:17076
        label: streptomycin
    - preferred_term: hydroxychloroquine
      term:
        id: CHEBI:5801
        label: hydroxychloroquine
  target_mechanisms:
  - target: Persistent multisystem infection
    treatment_effect: INHIBITS
    description: Hydroxychloroquine-containing triple therapy may reduce treatment failure, but evidence remains low certainty and investigational.
    evidence:
    - reference: DOI:10.1371/journal.pntd.0012010
      reference_title: "Efficacy and safety of therapeutic strategies for human brucellosis: A systematic review and network meta-analysis"
      supports: SUPPORT
      evidence_source: HUMAN_CLINICAL
      snippet: "The association of hydroxychloroquine to the dual regimen was identified as a potential strategy to prevent overall therapy failure, which is subject to confirmation in future studies."
      explanation: Supports the regimen as a promising but not yet definitive treatment strategy.
  - target: Bacterial Ribosomal Translation (Tetracycline/Aminoglycoside Target)
    treatment_effect: INHIBITS
    description: The doxycycline and streptomycin backbone binds the 30S ribosome and arrests bacterial protein synthesis.
  - target: Requirement for Cell-Penetrant Antimicrobials
    treatment_effect: INHIBITS
    description: >-
      Hydroxychloroquine alkalinizes the acidic Brucella-containing vacuole to
      improve intracellular aminoglycoside/doxycycline activity against the
      protected reservoir.
  evidence:
  - reference: DOI:10.1371/journal.pntd.0012010
    reference_title: "Efficacy and safety of therapeutic strategies for human brucellosis: A systematic review and network meta-analysis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The association of hydroxychloroquine to the dual regimen was identified as a potential strategy to prevent overall therapy failure, which is subject to confirmation in future studies."
    explanation: Conservatively supports hydroxychloroquine triple therapy as emerging/partial evidence pending confirmation.
diagnosis:
- name: Culture and serology reference standards
  description: Human brucellosis diagnostic studies commonly compare index tests against culture and/or standard tube agglutination testing.
  evidence:
  - reference: DOI:10.1371/journal.pntd.0012030
    reference_title: "Diagnosis of human brucellosis: Systematic review and meta-analysis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Regarding the reference test, culture and/or SAT are deemed more appropriate than culture alone."
    explanation: Supports culture and SAT as important reference standards.
- name: Rose Bengal, ELISA, and PCR testing
  description: Rose Bengal, IgG/IgM ELISA, and PCR are promising tools for confirming suspected human brucellosis when interpreted in context.
  evidence:
  - reference: DOI:10.1371/journal.pntd.0012030
    reference_title: "Diagnosis of human brucellosis: Systematic review and meta-analysis"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "Rose Bengal, IgG/IgM ELISA, and PCR exhibited equally high performances, indicating superior overall diagnostic accuracy, with very low certainty of the evidence."
    explanation: Supports these diagnostic modalities and preserves the evidence-certainty caveat.
- name: Combined serologic diagnostic algorithm
  description: Combining RBT with Brucellacapt and ELISA IgM/IgG improved diagnostic performance in a French reference-center study.
  evidence:
  - reference: DOI:10.1371/journal.pntd.0012442
    reference_title: "Diagnosis of brucellosis: Combining tests to improve performance"
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: "The most promising results were observed when an algorithm was built combining RBT, Brucellacapt, and ELISA for IgM and IgG (a score value of 0.5 with 90.5% for sensitivity, 99.7% for specificity, 92.4% for PPV, and 99.6% for NPV)."
    explanation: Supports combined serology algorithms as a diagnostic performance improvement strategy.
discussions:
- discussion_id: gap_brucellosis_regimen_focal_adult
  prompt: >-
    What is the optimal antibiotic regimen and duration for adult, focal, and
    complicated human brucellosis (spondylitis, sacroiliitis, endocarditis,
    neurobrucellosis), given that the strongest comparative-efficacy ranking
    (doxycycline + gentamicin) derives from a network meta-analysis restricted to
    children and adolescents that explicitly excluded focal disease and pregnancy?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Persistent multisystem infection
  rationale: >-
    The 2024 network meta-analysis that ranked doxycycline + gentamicin highest
    for efficacy restricted inclusion to trials of children and adolescents and
    excluded spondylitis, endocarditis, neurobrucellosis, and pregnancy, so its
    ranking cannot be applied directly to the focal and complicated adult disease
    that drives most brucellosis morbidity. Regimen choice and duration for these
    presentations still rest on heterogeneous observational data, and improved
    treatment regimens remain an explicitly stated open challenge in the field.
  evidence:
  - reference: PMID:18045560
    reference_title: "Human brucellosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "the development of improved treatment regimens"
    explanation: Authoritative review naming the development of improved treatment regimens as an unresolved challenge in human brucellosis.
  proposed_experiments:
  - experiment_id: exp_brucellosis_adult_focal_rct
    name: Multicenter randomized trial of doxycycline-gentamicin versus triple therapy in adult focal/complicated brucellosis
    description: >-
      Enroll adults with spondylitis, sacroiliitis, endocarditis, or
      neurobrucellosis and randomize to doxycycline + gentamicin versus a
      doxycycline-rifampicin-based triple regimen, with protocolized durations
      and long-term follow-up, using microbiologic cure, relapse, and
      treatment-failure as endpoints to define the best regimen for focal disease.
    experiment_type:
      preferred_term: randomized controlled trial
- discussion_id: gap_brucellosis_prognostic_biomarkers
  prompt: >-
    Which biomarkers predict disease severity, progression to focal or chronic
    disease, relapse risk, and treatment response in human brucellosis?
  kind: KNOWLEDGE_GAP
  status: OPEN
  attaches_to:
  - pathophysiology#Persistent multisystem infection
  rationale: >-
    Brucellosis is relapse-prone and can localize to bone, heart, and the nervous
    system, yet there is no validated marker to stratify which patients will
    progress, relapse, or fail therapy. The absence of severity/progression/
    treatment-response markers is a long-standing, explicitly stated gap that
    limits risk-adapted treatment intensity and duration.
  evidence:
  - reference: PMID:18045560
    reference_title: "Human brucellosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "the identification of markers for disease severity, progression, and treatment response"
    explanation: Authoritative review naming the lack of markers for severity, progression, and treatment response as an unresolved challenge.
  proposed_experiments:
  - experiment_id: exp_brucellosis_biomarker_cohort
    name: Prospective biomarker cohort for relapse and focal-progression prediction
    description: >-
      Follow a prospective cohort of culture- or serology-confirmed cases with
      serial serologic titers, inflammatory markers, and host-immune profiling
      from diagnosis through completion of therapy and relapse surveillance, to
      identify candidate biomarkers that predict focal progression, relapse, and
      treatment failure.
    experiment_type:
      preferred_term: prospective cohort study
- discussion_id: gap_brucellosis_mhc_evasion_human_relevance
  prompt: >-
    Does the IFN-gamma-induced MHC-I surface down-modulation by Brucella abortus
    RNA, shown in human epithelial, endothelial, and monocyte/macrophage cell
    lines in vitro, actually operate in vivo to sustain chronic human
    brucellosis, or is it a feature of the isolated-RNA cell-line system?
  kind: HUMAN_MODEL_MISMATCH
  status: OPEN
  attaches_to:
  - pathophysiology#MHC-I surface down-modulation
  - pathophysiology#Persistent multisystem infection
  rationale: >-
    The MHC-I down-modulation immune-evasion mechanism is supported entirely by
    in vitro experiments using human cell lines exposed to isolated B. abortus
    RNA. Whether this pathway meaningfully impairs CD8+ T-cell surveillance in
    infected patients — and thereby drives the persistence and relapse that
    define chronic brucellosis — has not been demonstrated in human tissue or in
    an in vivo model of chronic infection, so its translational weight is
    uncertain. Understanding Brucella pathogenic mechanisms remains an explicitly
    stated open challenge.
  evidence:
  - reference: PMID:18045560
    reference_title: "Human brucellosis."
    supports: SUPPORT
    evidence_source: OTHER
    snippet: "the understanding of pathogenic mechanisms of Brucella spp"
    explanation: Authoritative review naming the understanding of Brucella pathogenic mechanisms as an unresolved challenge, underscoring the translational gap for this in-vitro mechanism.
  proposed_experiments:
  - experiment_id: exp_brucellosis_mhc_invivo
    name: In vivo test of MHC-I down-modulation and CD8 surveillance in chronic brucellosis
    description: >-
      Assess surface MHC-I expression and CD8+ T-cell responses in cells from a
      chronic-infection animal model and in tissue or peripheral cells from
      patients with chronic or relapsing brucellosis, comparing infected versus
      uninfected states to test whether the in-vitro MHC-I down-modulation
      operates during genuine intracellular infection.
    experiment_type:
      preferred_term: controlled perturbation experiment
clinical_trials: []
datasets:
- accession: geo:GSE107554
  title: Evaluation of immunological factors involved in initiation of chronic brucellosis in CD4+ T cells using miRNA array
  description: Brucellosis is a serious infectious disease and continues to be an important cause of morbidity. It can be seen almost anywhere in the world and at any age. Acute phase heals or becomes chronic form. Infection of 10-30% of patients becomes chronic, despite early diagnosis and treatment. Although our knowledge about Brucella virulence factors and the host response increase rapidly, how they can hidden from the immune system and cause chronic disease are still unknown. We aimed to investigate the immunological factors which belong to CD4+ T cells and their roles in the transition of brucellosis from acute to chronic infection.
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  data_type: MICROARRAY
  sample_count: 23
  publication: PMID:29897958
  notes: Identified by GEO DataSets index search for Brucellosis (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
- accession: geo:GSE69597
  title: Refining brucellosis diagnosis by blood transcriptional profiling.
  description: Diagnosis of brucellosis remains challenging for several reasons, including lack of culture sensitivity, nonspecific symptomatology, and high prevalence of positive serology in endemic areas. The main objectives of this study were to identify blood biomarkers specific to brucellosis compared to other endemic infections and to monitor changes in blood biomarkers during treatment. To obtain a global profile of the disease, we employed RNA sequencing (RNAseq) of whole blood RNA to measure host response against brucellosis infection in patients from Macedonia and Spain.
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  data_type: BULK_RNA_SEQ
  sample_count: 169
  notes: Identified by GEO DataSets index search for Brucellosis (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
- accession: geo:GSE87537
  title: MICRORNA EXPRESSİON PATTERNS OF CD8+ T CELLS IN ACUTE AND CHRONIC BRUCELLOSIS
  description: Using miRNA microarray, more than 2000 miRNAs were screened in CD8 + T cells of patients with acute or chronic brucellosis and healthy controls that were sorted from peripheral blood with flow cytometry and validated through qRT-PCR.
  organism:
    preferred_term: human
    term:
      id: NCBITaxon:9606
      label: Homo sapiens
  data_type: MICROARRAY
  sample_count: 23
  notes: Identified by GEO DataSets index search for Brucellosis (scripts/discover_datasets.py); accession and metadata verified against NCBI E-utilities on 2026-08-01. Title, sample count, and organism are GEO's own values.
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Edison Scientific Literature 55 citations 2026-05-08T09:35:56.858177

Question: You are an expert researcher providing comprehensive, well-cited information.

Provide detailed information focusing on: 1. Key concepts and definitions with current understanding 2. Recent developments and latest research (prioritize 2023-2024 sources) 3. Current applications and real-world implementations 4. Expert opinions and analysis from authoritative sources 5. Relevant statistics and data from recent studies

Format as a comprehensive research report with proper citations. Include URLs and publication dates where available. Always prioritize recent, authoritative sources and provide specific citations for all major claims.

Disease Characteristics Research Template

Target Disease

  • Disease Name: Brucellosis
  • MONDO ID: (if available)
  • Category: Infectious

Research Objectives

Please provide a comprehensive research report on Brucellosis covering all of the disease characteristics listed below. This report will be used to populate a disease knowledge base entry. Be thorough and cite primary literature (PMID preferred) for all claims.

For each section, suggested databases/resources are listed. These are the first places you should search for information on each topic.

1. Disease Information

Search first: OMIM, Orphanet, ICD-10/ICD-11, MeSH, PubMed

  • What is the disease? Provide a concise overview.
  • What are the key identifiers? (OMIM, Orphanet, ICD-10/ICD-11, MeSH, Mondo)
  • What are the common synonyms and alternative names?
  • Is the information derived from individual patients (e.g., EHR) or aggregated disease-level resources?

2. Etiology

  • Disease Causal Factors: What are the primary causes? (genetic, environmental, infectious, mechanistic)
  • Risk Factors:

    Search first: PubMed, Cochrane Library, UpToDate, clinical guidelines, ClinVar, ClinGen, GWAS Catalog, PheGenI, CTD, CDC, WHO, epidemiological databases

  • Genetic risk factors (causal variants, susceptibility loci, modifier genes)
  • Environmental risk factors (toxins, lifestyle, occupational exposures, age, sex, family history)
  • Protective Factors:

    Search first: PubMed, Cochrane Library, clinical trial databases, GWAS Catalog, gnomAD, WHO, CDC, nutrition databases

  • Genetic protective factors (protective variants, modifier alleles)
  • Environmental protective factors (diet, lifestyle, exposures that reduce risk)
  • Gene-Environment Interactions: How do genetic and environmental factors interact to influence disease?

    Search first: CTD, PubMed, PheGenI, GxE databases

3. Phenotypes

Search first: HPO (Human Phenotype Ontology), OMIM, Orphanet, PubMed, clinicaltrials.gov, MedDRA, SNOMED CT, DECIPHER, LOINC

For each phenotype, provide: - Phenotype type: symptoms, clinical signs, physical manifestations, behavioral changes, or laboratory abnormalities

For symptoms/signs: HPO, OMIM, Orphanet, PubMed For behavioral changes: HPO, DSM, RDoC (Research Domain Criteria), PubMed For laboratory abnormalities: LOINC, SNOMED CT, LabTests Online, PubMed - Phenotype characteristics: Search first: OMIM, Orphanet, HPO, PubMed - Age of symptom onset (neonatal, childhood, adult-onset, late-onset) - Symptom severity (mild, moderate, severe, variable) - Symptom progression (stable, progressive, episodic, fluctuating) - Frequency among affected individuals (percentage or qualitative) - Quality of life impact: Effects on daily functioning and well-being (per-phenotype when possible) Search first: EQ-5D database, SF-36, WHO QOL databases, PubMed - Suggest HPO (Human Phenotype Ontology) terms for each phenotype

4. Genetic/Molecular Information

  • Causal Genes: Gene mutations or chromosomal abnormalities responsible for disease (gene symbols, OMIM IDs)

    Search first: OMIM, ClinVar, HGMD, Ensembl, NCBI Gene

  • Pathogenic Variants:
  • Affected genes (gene symbols, HGNC IDs) > Search first: OMIM, NCBI Gene, Ensembl, HGNC, UniProt, GeneCards
  • Variant classification (pathogenic, likely pathogenic, VUS per ACMG/AMP guidelines) > Search first: ClinVar, ClinGen, ACMG/AMP guidelines, VarSome
  • Variant type/class (missense, frameshift, nonsense, splice-site, structural)
  • Allele frequency in population databases > Search first: gnomAD, 1000 Genomes, ExAC, TOPMed, dbSNP
  • Somatic vs germline origin > Search first: COSMIC (somatic), ClinVar, ICGC, TCGA
  • Functional consequences (loss of function, gain of function, dominant negative)
  • Modifier Genes: Genes that modify disease severity or expression
  • Epigenetic Information: DNA methylation, histone modifications, chromatin changes affecting disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Chromosomal Abnormalities: Large-scale genetic changes (aneuploidy, translocations, inversions)

    Search first: DECIPHER, ClinVar, ECARUCA, UCSC Genome Browser

5. Environmental Information

  • Environmental Factors: Non-genetic contributing factors (toxins, radiation, pollution, occupational exposure)

    Search first: CTD (Comparative Toxicogenomics Database), TOXNET, PubMed, EPA databases

  • Lifestyle Factors: Behavioral factors (smoking, diet, exercise, alcohol consumption)

    Search first: CDC databases, WHO, PubMed, NHANES

  • Infectious Agents: If applicable, pathogens causing or triggering disease (bacteria, viruses, fungi, parasites)

    Search first: NCBI Taxonomy, ViPR, BV-BRC, MicrobeDB, GIDEON

6. Mechanism / Pathophysiology

  • Molecular Pathways: Specific signaling cascades or biochemical pathways involved (Wnt, MAPK, mTOR, PI3K-AKT, etc.)

    Search first: KEGG, Reactome, WikiPathways, PathBank, BioCyc

  • Cellular Processes: Cell-level mechanisms (apoptosis, autophagy, cell cycle dysregulation, inflammation, etc.)

    Search first: Gene Ontology (GO), Reactome, KEGG, PubMed

  • Protein Dysfunction: How protein structure or function is altered (misfolding, aggregation, loss of function, gain of function)

    Search first: UniProt, PDB (Protein Data Bank), InterPro, Pfam, AlphaFold

  • Metabolic Changes: Alterations in metabolic processes (energy metabolism, lipid metabolism, amino acid metabolism)

    Search first: KEGG, BioCyc, HMDB (Human Metabolome Database), BRENDA

  • Immune System Involvement: Role of immune response (autoimmunity, immunodeficiency, chronic inflammation)

    Search first: ImmPort, Immunome Database, IEDB, Gene Ontology

  • Tissue Damage Mechanisms: How tissues/ are injured (oxidative stress, ischemia, fibrosis, necrosis)

    Search first: PubMed, Gene Ontology, Reactome

  • Biochemical Abnormalities: Specific molecular defects (enzyme deficiencies, receptor dysfunction, ion channel defects)

    Search first: BRENDA, UniProt, KEGG, OMIM, PubMed

  • Epigenetic Changes: DNA methylation, histone modifications affecting gene expression in disease

    Search first: ENCODE, Roadmap Epigenomics, MethBase, DiseaseMeth

  • Molecular Profiling (if available):
  • Transcriptomics/gene expression changes > Search first: GEO (Gene Expression Omnibus), ArrayExpress, GTEx, Human Cell Atlas, SRA
  • Proteomics findings > Search first: PRIDE, ProteomeXchange, Human Protein Atlas, STRING, BioGRID
  • Metabolomics signatures > Search first: MetaboLights, Metabolomics Workbench, HMDB, METLIN
  • Lipidomics alterations > Search first: LIPID MAPS, SwissLipids, LipidHome, Metabolomics Workbench
  • Genomic structural features > Search first: UCSC Genome Browser, Ensembl, NCBI, dbVar, DGV
  • Advanced Technologies (if applicable):
  • Single-cell analysis findings (cell-type specific mechanisms, cellular heterogeneity) > Search first: Human Cell Atlas, Single Cell Portal, GEO, CELLxGENE
  • Spatial transcriptomics findings > Search first: GEO, Spatial Research, Vizgen, 10x Genomics data
  • Multi-omics integration results > Search first: TCGA, ICGC, cBioPortal, LinkedOmics, PubMed
  • Functional genomics screens (CRISPR, RNAi) > Search first: DepMap, GenomeRNAi, PubMed, BioGRID ORCS

For each mechanism, describe: - The causal chain from initial trigger to clinical manifestation - Which mechanisms are upstream vs downstream - What cell types and biological processes are involved - Suggest GO terms for biological processes and CL terms for cell types

7. Anatomical Structures Affected

  • Organ Level:
  • Primary organs directly affected
  • Secondary organ involvement (complications, secondary effects)
  • Body systems involved (cardiovascular, nervous, digestive, respiratory, endocrine, etc.)

    Search first: Uberon, FMA (Foundational Model of Anatomy), OMIM, HPO, ICD-11, MeSH, SNOMED CT

  • Tissue and Cell Level:
  • Specific tissue types affected (epithelial, connective, muscle, nervous)
  • Specific cell populations targeted (with Cell Ontology terms)

    Search first: Uberon, Human Protein Atlas, Cell Ontology, Human Cell Atlas, CellMarker, PanglaoDB

  • Subcellular Level:
  • Cellular compartments involved (mitochondria, nucleus, ER, lysosomes) (with GO Cellular Component terms)

    Search first: Gene Ontology (Cellular Component), UniProt, Human Protein Atlas

  • Localization:
  • Specific anatomical sites (with UBERON terms) > Search first: FMA, Uberon, NeuroNames (for brain), SNOMED CT
  • Lateralization (unilateral, bilateral, asymmetric) > Search first: HPO, clinical literature, imaging databases

8. Temporal Development

  • Onset:
  • Typical age of onset (congenital, pediatric, adult, geriatric)
  • Onset pattern (acute, subacute, chronic, insidious)

    Search first: OMIM, Orphanet, HPO, PubMed

  • Progression:
  • Disease stages (early, intermediate, advanced, end-stage) > Search first: Cancer Staging Manual (AJCC), WHO classifications, PubMed
  • Progression rate (rapid, slow, variable)
  • Disease course pattern (episodic, relapsing-remitting, progressive, stable)
  • Disease duration (self-limited, chronic lifelong)

    Search first: Disease registries, longitudinal cohort databases, natural history studies, PubMed, Orphanet, OMIM

  • Patterns:
  • Remission patterns (spontaneous, treatment-induced) > Search first: Clinical trial databases, disease registries, PubMed
  • Critical periods (time windows of vulnerability or opportunity for intervention) > Search first: PubMed, developmental biology databases, clinical guidelines

9. Inheritance and Population

  • Epidemiology:
  • Prevalence (cases per 100,000 at given time)
  • Incidence (new cases per 100,000 per year)

    Search first: Orphanet, CDC, WHO, GBD (Global Burden of Disease), national registries, SEER, disease registries

  • For Genetic Etiology:
  • Inheritance pattern (AD, AR, X-linked, mitochondrial, multifactorial, polygenic) > Search first: OMIM, Orphanet, ClinVar, GTR (Genetic Testing Registry)
  • Penetrance (complete, incomplete, age-dependent) > Search first: ClinVar, OMIM, PubMed, ClinGen
  • Expressivity (variable, consistent) > Search first: OMIM, ClinVar, PubMed
  • Genetic anticipation (increasing severity in successive generations) > Search first: OMIM, PubMed (especially for repeat expansion disorders)
  • Germline mosaicism > Search first: ClinVar, OMIM, genetic counseling literature, PubMed
  • Founder effects (population-specific mutations) > Search first: gnomAD, population genetics databases, PubMed
  • Consanguinity role > Search first: OMIM, population studies, genetic counseling resources
  • Carrier frequency > Search first: gnomAD, carrier screening databases, GeneReviews, GTR
  • Population Demographics:
  • Affected populations (ethnic or demographic groups with higher prevalence) > Search first: gnomAD, 1000 Genomes, PAGE Study, PubMed, population registries
  • Geographic distribution (endemic areas, regional variation) > Search first: WHO, CDC, GBD, Orphanet, geographic epidemiology databases
  • Geographic distribution of specific variants
  • Sex ratio (male:female) > Search first: Disease registries, OMIM, PubMed, epidemiological databases
  • Age distribution of affected individuals > Search first: CDC, disease registries, SEER, Orphanet

10. Diagnostics

  • Clinical Tests:
  • Laboratory tests (blood, urine, tissue chemistry, specific enzyme assays) > Search first: LOINC, LabTests Online, PubMed
  • Biomarkers (proteins, metabolites, genetic markers, circulating biomarkers) > Search first: FDA Biomarker List, BEST (Biomarkers, EndpointS, and other Tools), PubMed
  • Imaging studies (X-ray, CT, MRI, PET, ultrasound) > Search first: RadLex, DICOM, Radiopaedia, imaging databases
  • Functional tests (pulmonary function, cardiac stress tests) > Search first: LOINC, clinical guidelines, PubMed
  • Electrophysiology (EEG, EMG, ECG, nerve conduction studies) > Search first: LOINC, clinical neurophysiology databases, PubMed
  • Biopsy findings (histopathology, immunohistochemistry) > Search first: SNOMED CT, College of American Pathologists resources, PubMed
  • Pathology findings (microscopic examination) > Search first: SNOMED CT, Digital Pathology databases, PubMed
  • Genetic Testing:

    Search first: GTR (Genetic Testing Registry), GeneReviews, ClinGen

  • Overview of recommended genetic testing approach
  • Whole genome sequencing (WGS) utility > Search first: GTR, ClinVar, GEL (Genomics England), gnomAD
  • Whole exome sequencing (WES) utility > Search first: GTR, ClinVar, OMIM, GeneMatcher
  • Gene panels (which panels, which genes) > Search first: GTR, ClinVar, laboratory-specific databases
  • Single gene testing > Search first: GTR, ClinVar, OMIM, GeneReviews
  • Chromosomal microarray (CMA) > Search first: DECIPHER, ClinVar, dbVar, ECARUCA
  • Karyotyping > Search first: Chromosome Abnormality Database, ClinVar, cytogenetics resources
  • FISH > Search first: ClinVar, cytogenetics databases, PubMed
  • Mitochondrial DNA testing > Search first: MITOMAP, MSeqDR, ClinVar, GTR
  • Repeat expansion testing > Search first: GTR, ClinVar, repeat expansion databases, PubMed
  • Omics-Based Diagnostics (if applicable):
  • RNA sequencing / transcriptomics > Search first: GEO, ArrayExpress, GTEx, RNA-seq databases
  • Proteomics > Search first: PRIDE, ProteomeXchange, FDA Biomarker database
  • Metabolomics > Search first: MetaboLights, Metabolomics Workbench, HMDB
  • Epigenomics > Search first: GEO, ENCODE, Roadmap Epigenomics, MethBase
  • Liquid biopsy > Search first: COSMIC, ClinVar, liquid biopsy databases, PubMed
  • Clinical Criteria:
  • Standardized diagnostic criteria (DSM, ICD, society guidelines) > Search first: DSM-5, ICD-11, clinical society guidelines, UpToDate
  • Differential diagnosis (other conditions to rule out, with distinguishing features) > Search first: DynaMed, UpToDate, clinical decision support systems
  • Screening:
  • Screening methods for asymptomatic individuals (newborn screening, carrier screening, cascade screening) > Search first: ACMG recommendations, CDC newborn screening, GTR

11. Outcome/Prognosis

  • Survival and Mortality:
  • Survival rate (5-year, 10-year, overall) > Search first: SEER, cancer registries, disease-specific registries, PubMed
  • Life expectancy (with and without treatment if applicable) > Search first: Orphanet, disease registries, actuarial databases, PubMed
  • Mortality rate > Search first: CDC, WHO, GBD, national mortality databases
  • Disease-specific mortality (deaths directly attributable to disease) > Search first: Disease registries, CDC Wonder, GBD, PubMed
  • Morbidity and Function:
  • Morbidity (disease-related disability and health impacts) > Search first: GBD, WHO, disability databases, PubMed
  • Disability outcomes (long-term functional impairments) > Search first: ICF (International Classification of Functioning), disability registries
  • Quality of life measures (EQ-5D, SF-36, PROMIS, disease-specific tools) > Search first: EQ-5D database, SF-36, PROMIS, PubMed
  • Disease Course:
  • Complications (secondary problems: infections, organ failure, etc.) > Search first: ICD codes, disease registries, clinical databases, PubMed
  • Recovery potential (likelihood and extent of recovery, with vs without treatment) > Search first: Natural history studies, rehabilitation databases, PubMed
  • Prediction:
  • Prognostic factors (age, disease severity, biomarkers, treatment response) > Search first: Prognostic models databases, clinical calculators, PubMed
  • Prognostic biomarkers (molecular markers predicting disease course) > Search first: FDA Biomarker database, PubMed, cancer prognostic databases

12. Treatment

  • Pharmacotherapy:
  • Pharmacological treatments (drug names, drug classes, mechanisms of action) > Search first: DrugBank, RxNorm, ATC classification, DailyMed, FDA databases
  • Pharmacogenomics (how genetic variants affect drug metabolism, efficacy, toxicity) > Search first: PharmGKB, CPIC (Clinical Pharmacogenetics), FDA Table of PGx Biomarkers
  • Advanced Therapeutics:
  • Gene therapy (viral vectors, CRISPR, gene replacement, gene editing) > Search first: ClinicalTrials.gov, FDA gene therapy database, ASGCT resources
  • Cell therapy (stem cell transplant, CAR-T, cellular therapeutics) > Search first: ClinicalTrials.gov, FDA cell therapy database, FACT standards
  • RNA-based therapies (ASOs, siRNA, mRNA therapies) > Search first: ClinicalTrials.gov, FDA approvals, PubMed
  • Targeted therapies (treatments directed at specific molecular targets) > Search first: My Cancer Genome, OncoKB, ClinicalTrials.gov, FDA approvals
  • Immunotherapies (checkpoint inhibitors, monoclonal antibodies) > Search first: Cancer Immunotherapy Database, FDA approvals, ClinicalTrials.gov
  • Surgical and Interventional:
  • Surgical interventions (types of surgery, timing, outcomes) > Search first: CPT codes, surgical registries, clinical guidelines, PubMed
  • Supportive and Rehabilitative:
  • Supportive care (symptom management, pain control, nutrition) > Search first: Clinical guidelines, Cochrane Library, PubMed
  • Rehabilitation (physical therapy, occupational therapy, speech therapy) > Search first: Rehabilitation medicine databases, clinical guidelines, PubMed
  • Experimental:
  • Experimental treatments in clinical trials (with NCT identifiers if available) > Search first: ClinicalTrials.gov, EU Clinical Trials Register, WHO ICTRP
  • Treatment Outcomes:
  • Treatment response rates > Search first: Clinical trial databases, FDA reviews, systematic reviews, PubMed
  • Side effects and adverse events > Search first: FDA Adverse Event Reporting System (FAERS), MedWatch, PubMed
  • Treatment Strategy:
  • Treatment algorithms (clinical pathways, decision trees) > Search first: Clinical practice guidelines, NCCN Guidelines, UpToDate
  • Combination therapies > Search first: ClinicalTrials.gov, treatment guidelines, PubMed
  • Personalized medicine approaches (genotype-guided treatment) > Search first: My Cancer Genome, CIViC, PharmGKB, precision medicine databases

For each treatment, suggest MAXO (Medical Action Ontology) terms where applicable.

13. Prevention

  • Prevention Levels:
  • Primary prevention (preventing disease occurrence: vaccination, risk factor modification) > Search first: CDC, WHO, USPSTF recommendations, Cochrane Library
  • Secondary prevention (early detection and treatment: screening programs, early intervention) > Search first: USPSTF, CDC screening guidelines, WHO
  • Tertiary prevention (preventing complications in those with disease) > Search first: Clinical guidelines, disease management protocols, PubMed
  • Immunization: Vaccine strategies (if applicable)

    Search first: CDC vaccine schedules, WHO immunization, FDA vaccine database

  • Screening and Early Detection:
  • Screening programs (population-based: newborn screening, cancer screening) > Search first: CDC screening programs, USPSTF, cancer screening databases
  • Genetic screening (carrier screening, preimplantation genetic diagnosis, prenatal testing) > Search first: ACMG recommendations, ACOG guidelines, GTR
  • Risk stratification (identifying high-risk individuals for targeted prevention) > Search first: Risk prediction models, clinical calculators, PubMed
  • Behavioral Interventions: Lifestyle modifications to reduce risk

    Search first: CDC, WHO, behavioral intervention databases, Cochrane Library

  • Counseling: Genetic counseling (risk assessment, family planning guidance)

    Search first: NSGC resources, ACMG guidelines, GeneReviews

  • Public Health:
  • Public health interventions (sanitation, vector control, health education) > Search first: CDC, WHO, public health databases, PubMed
  • Environmental interventions (reducing environmental risk factors) > Search first: EPA databases, WHO environmental health, PubMed
  • Prophylaxis: Preventive medications or procedures

    Search first: Clinical guidelines, FDA approvals, PubMed

14. Other Species / Natural Disease

  • Taxonomy: Species affected (with NCBI Taxon identifiers)

    Search first: NCBI Taxonomy

  • Breed: Specific breeds affected (with VBO identifiers if applicable)

    Search first: VBO (Vertebrate Breed Ontology)

  • Gene: Orthologous genes in other species (with NCBI Gene IDs)

    Search first: NCBI Gene

  • Natural Disease:
  • Naturally occurring disease in other species (companion animals, wildlife) > Search first: OMIA (Online Mendelian Inheritance in Animals), VetCompass, PubMed
  • Veterinary relevance and importance in animal health > Search first: OMIA, veterinary databases, PubMed
  • Comparative Biology:
  • Comparative pathology (similarities and differences across species) > Search first: OMIA, comparative pathology databases, PubMed
  • Evolutionary conservation of disease mechanisms > Search first: HomoloGene, OrthoMCL, Alliance of Genome Resources
  • Transmission (if applicable):
  • Zoonotic potential > Search first: CDC zoonotic diseases, WHO zoonoses, GIDEON
  • Cross-species susceptibility > Search first: NCBI Taxonomy, veterinary databases, PubMed

15. Model Organisms

  • Model Types:
  • Model organism type (mammalian, invertebrate, cellular, in vitro) > Search first: Alliance of Genome Resources, model organism databases
  • Specific model systems (mouse, rat, zebrafish, Drosophila, C. elegans, yeast, cell lines, organoids, iPSCs) > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, SGD, ATCC, Cellosaurus
  • Induced models (drug treatment, surgical intervention, environmental manipulation) > Search first: MGI, model organism databases, PubMed
  • Genetic Models:
  • Types available (knockout, knock-in, transgenic, conditional, humanized) > Search first: MGI, IMPC, KOMP, EuMMCR, IMSR
  • Model Characteristics:
  • Phenotype recapitulation (how well model reproduces human disease features) > Search first: Model organism databases, comparative studies, PubMed
  • Model limitations (aspects of human disease not captured) > Search first: Model organism databases, PubMed, review articles
  • Applications:
  • Research applications (what aspects of disease can be studied) > Search first: Model organism databases, PubMed
  • Resources:
  • Model databases > Search first: MGI, RGD, ZFIN, FlyBase, WormBase, IMSR, EMMA, MMRRC

Citation Requirements

  • Cite primary literature (PMID preferred) for all mechanistic and clinical claims
  • Prioritize recent reviews and landmark papers
  • Include direct quotes from abstracts where possible to support key statements
  • Distinguish evidence source types: human clinical, model organism, in vitro, computational

Output Format

Structure your response as a comprehensive narrative organized by the sections above. For each section, provide: - Factual content with specific details (numbers, percentages, gene names, variant nomenclature) - Ontology term suggestions (HPO, GO, CL, UBERON, CHEBI, MAXO, MONDO) where applicable - Evidence citations with PMIDs - Direct quotes from abstracts to support key claims - Clear indication when information is not available or not applicable for this disease

This report will be used to populate a disease knowledge base entry with: - Pathophysiology descriptions with causal chains - Gene/protein annotations (HGNC, GO terms) - Phenotype associations (HP terms) with frequencies - Cell type involvement (CL terms) - Anatomical locations (UBERON terms) - Chemical entities (CHEBI terms) - Treatment annotations (MAXO terms) - Evidence items with PMIDs and exact abstract quotes - Epidemiology, prognosis, diagnostic, and prevention information - Animal model descriptions with phenotype recapitulation details

Brucellosis (Disease Characteristics Research Report)

Target disease

  • Disease name: Brucellosis (human brucellosis)
  • Category: Infectious; zoonotic bacterial disease
  • MONDO ID: Not retrievable from the currently available, citable full-text corpus in this run (reported as unavailable rather than inferred) (ayoubi2024themanyfaces pages 1-2).

Executive summary (current understanding; 2023–2024 priority)

Brucellosis is a multisystem zoonotic infection caused by Brucella spp. and remains widely endemic and underdiagnosed, with modern global modeling estimating ~2.1 million human cases/year—substantially higher than historically assumed (Laine et al., Sep 2023, Emerging Infectious Diseases, https://doi.org/10.3201/eid2909.230052) (laine2023globalestimateof pages 1-2). Transmission is primarily foodborne (unpasteurized dairy) and occupational (animal contact), but documented additional routes include inhalation of aerosols and vertical transmission in special contexts (ayoubi2024themanyfaces pages 1-2, moriyon2023brucellosisandone pages 1-2, huy2024exploringtheimpact pages 1-2). Diagnostic progress in 2023–2024 emphasizes combining serologic tests and newer immunoassay approaches; pooled evidence suggests Rose Bengal, ELISA, and PCR can all perform well, but certainty of evidence is often low and algorithms outperform single tests in practice (Freire et al., Mar 2024, https://doi.org/10.1371/journal.pntd.0012030; Loubet et al., Sep 2024, https://doi.org/10.1371/journal.pntd.0012442) (freire2024diagnosisofhuman pages 9-11, loubet2024diagnosisofbrucellosis pages 1-2). Treatment evidence in 2024 network meta-analyses supports aminoglycoside-containing doxycycline regimens and some triple-therapy strategies as more effective than doxycycline–rifampicin for overall failure/relapse endpoints, though evidence certainty varies (Silva et al., Mar 2024, https://doi.org/10.1371/journal.pntd.0012010; Huang et al., Aug 2024, https://doi.org/10.1371/journal.pntd.0012405; Maduranga et al., Aug 2024, https://doi.org/10.1038/s41598-024-69669-w) (silva2024efficacyandsafety pages 18-21, huang2024updatedtherapeuticoptions pages 1-2, maduranga2024asystematicreview pages 3-6).

A compact table of key quantitative statistics is provided here:

Domain Key finding (with numbers) Population/setting Study type Publication (first author year journal) Publication date/month URL Citations
Global burden/incidence Conservative global annual incidence estimate: 2.1 million cases/year; highest burden in Africa and Asia Global Modeling study using international surveillance/public health data Laine 2023 Emerging Infectious Diseases 2023 Sep https://doi.org/10.3201/eid2909.230052 (laine2023globalestimateof pages 1-2)
Global prevalence Pooled prevalence 15.49% (95% CI 12.01–18.97); Asia 16.65%, Africa 16.28%, Americas 11.09%; male 19.11% vs female 13.97% 69 studies worldwide Systematic review and meta-analysis Sherasiya 2024 preprint 2024 Sep https://doi.org/10.21203/rs.3.rs-4929733/v1 (sherasiya2024globalprevalenceof pages 1-4, sherasiya2024globalprevalenceof pages 7-10)
National epidemiology 2,489 culture-confirmed cases (2004–2022); 99.8% bacteraemic; 64% male; mean age 30.5 y; B. melitensis 99.6%; annual incidence 1.6/100,000 overall, 6.6/100,000 Arab, 5.5/100,000 Druze, 0.18/100,000 Jewish; Arab South District peak 41.0/100,000 in 2012 Israel national surveillance, 2004–2022 National retrospective epidemiology study Weinberger 2024 Epidemiology and Infection 2024 May https://doi.org/10.1017/S0950268824000803 (weinberger2024nationalepidemiologyof pages 2-3, weinberger2024nationalepidemiologyof pages 1-2)
Regional epidemiology Overall pooled seroprevalence 5.0% (95% CI 3.0–6.0); human 6.9% (95% CI 4.9–8.8); cattle 3.5% (95% CI 2.2–4.7); heterogeneity I² 99.61% Ethiopia, 39 studies (2015–2024) Systematic review and meta-analysis Dagnaw 2024 BMC Public Health 2024 Dec https://doi.org/10.1186/s12889-024-21042-2 (dagnaw2024humanandanimal pages 1-2)
Risk factors Major risks: raw milk/unpasteurized dairy, contact with aborted materials/fetuses, occupation (livestock owners, abattoir workers, veterinarians), direct animal contact Global/Ethiopia/Israel Mixed: modeling, meta-analysis, national epidemiology Multiple recent sources 2023–2024 https://doi.org/10.3201/eid2909.230052 (weinberger2024nationalepidemiologyof pages 1-2, laine2023globalestimateof pages 1-2, sherasiya2024globalprevalenceof pages 1-4, dagnaw2024humanandanimal pages 1-2)
Diagnostic accuracy Rose Bengal pooled sensitivity/specificity vs culture: 89.7% / 94.1%; vs culture and/or SAT: 96.6% / 97.9% Symptomatic suspected human brucellosis Systematic review and meta-analysis Freire 2024 PLOS Neglected Tropical Diseases 2024 Mar https://doi.org/10.1371/journal.pntd.0012030 (freire2024diagnosisofhuman pages 9-11, freire2024diagnosisofhuman pages 1-2)
Diagnostic accuracy SAT pooled sensitivity/specificity vs culture: 89.2% / 95.6% Symptomatic suspected human brucellosis Systematic review and meta-analysis Freire 2024 PLOS Neglected Tropical Diseases 2024 Mar https://doi.org/10.1371/journal.pntd.0012030 (freire2024diagnosisofhuman pages 9-11)
Diagnostic accuracy IgG ELISA pooled sensitivity/specificity vs culture: 82.9% / 96.2%; specificity vs culture and/or SAT reached 99.0% Symptomatic suspected human brucellosis Systematic review and meta-analysis Freire 2024 PLOS Neglected Tropical Diseases 2024 Mar https://doi.org/10.1371/journal.pntd.0012030 (freire2024diagnosisofhuman pages 9-11)
Diagnostic accuracy IgM ELISA pooled sensitivity/specificity vs culture: 84.5% / 95.3% Symptomatic suspected human brucellosis Systematic review and meta-analysis Freire 2024 PLOS Neglected Tropical Diseases 2024 Mar https://doi.org/10.1371/journal.pntd.0012030 (freire2024diagnosisofhuman pages 9-11)
Diagnostic accuracy Qualitative PCR pooled sensitivity/specificity vs culture: 96.4% / 98.1%; real-time PCR: 81.9% / 91.5% Symptomatic suspected human brucellosis Systematic review and meta-analysis Freire 2024 PLOS Neglected Tropical Diseases 2024 Mar https://doi.org/10.1371/journal.pntd.0012030 (freire2024diagnosisofhuman pages 9-11)
Diagnostic algorithm Combined RBT + Brucellacapt + ELISA IgM/IgG achieved 90.5% sensitivity, 99.7% specificity, 92.4% PPV, 99.6% NPV French National Reference Center, 3,587 sera; 148 confirmed cases Retrospective diagnostic accuracy study Loubet 2024 PLOS Neglected Tropical Diseases 2024 Sep https://doi.org/10.1371/journal.pntd.0012442 (loubet2024diagnosisofbrucellosis pages 1-2)
Treatment comparative efficacy Standard doxycycline + rifampicin had higher failure risk than triple therapy adding streptomycin: RR 1.98 (95% CI 1.17–3.35); and adding levofloxacin: RR 2.98 (95% CI 1.67–5.32) Human brucellosis, 34 studies, 4,182 participants Systematic review and meta-analysis Maduranga 2024 Scientific Reports 2024 Aug https://doi.org/10.1038/s41598-024-69669-w (maduranga2024asystematicreview pages 3-6, maduranga2024asystematicreview pages 1-2)
Treatment comparative efficacy Doxycycline + rifampicin had higher relapse risk than triple therapy with streptomycin: RR 22.12 (95% CI 3.48–140.52); and with levofloxacin: RR 4.61 (95% CI 2.20–9.66) Human brucellosis, 34 studies, 4,182 participants Systematic review and meta-analysis Maduranga 2024 Scientific Reports 2024 Aug https://doi.org/10.1038/s41598-024-69669-w (maduranga2024asystematicreview pages 3-6, maduranga2024asystematicreview pages 1-2)
Treatment comparative efficacy In NMA, doxycycline + rifampicin had higher failure risk than doxycycline + streptomycin: RR 1.96 (95% CI 1.27–3.01); doxycycline + gentamicin lower than doxycycline + rifampicin: RR 0.30 (95% CI 0.14–0.62) 31 RCTs, 4,167 patients Systematic review and network meta-analysis Silva 2024 PLOS Neglected Tropical Diseases 2024 Mar https://doi.org/10.1371/journal.pntd.0012010 (silva2024efficacyandsafety pages 18-21, silva2024efficacyandsafety pages 21-22, silva2024efficacyandsafety pages 22-24)
Treatment ranking Doxycycline + gentamicin ranked best by SUCRA (0.94), followed by triple therapy 0.87 and doxycycline + streptomycin 0.78; authors suggest 6 weeks doxycycline + 1–2 weeks gentamicin or 2–3 weeks streptomycin 43 RCTs, 4,283 patients Systematic review and network meta-analysis Huang 2024 PLOS Neglected Tropical Diseases 2024 Aug https://doi.org/10.1371/journal.pntd.0012405 (huang2024updatedtherapeuticoptions pages 1-2)
Bacteremic disease treatment Oral doxycycline–rifampicin and IV gentamicin–doxycycline–rifampicin showed similar response; negative blood culture at 4 weeks 90.3%, overall recovery 93.5%, no deaths 93 adults with brucellosis bacteremia Observational comparative study Nazir 2024 Journal of University Medical & Dental College 2024 Aug https://doi.org/10.37723/jumdc.v15i3.920 (nazir2024responseofthe pages 1-2)

Table: This table compiles recent quantitative evidence on brucellosis burden, epidemiology, diagnostics, and treatment efficacy. It is designed as a compact reference for knowledge-base population and citation tracing.

1. Disease information

1.1 What is brucellosis?

Brucellosis is a zoonotic, often insidious, multisystem infectious disease caused by bacteria of the genus Brucella. Contemporary clinical reviews emphasize its protean manifestations and diagnostic difficulty because presentations overlap with other febrile illnesses (Ayoubi et al., Jul 2024, Current Opinion in Infectious Diseases, https://doi.org/10.1097/QCO.0000000000001045) (ayoubi2024themanyfaces pages 1-2).

1.2 Common synonyms / alternative names

A 2024 clinical review explicitly lists: “Mediterranean flaccid fever,” “Malta fever,” and “undulant fever.” (Ayoubi et al., Jul 2024, https://doi.org/10.1097/QCO.0000000000001045) (ayoubi2024themanyfaces pages 1-2).

1.3 Key identifiers (OMIM / Orphanet / ICD / MeSH / MONDO)

  • ICD-10 / ICD-11 / MeSH / MONDO / Orphanet: Not extractable with citable evidence from the retrieved corpus in this run. This report therefore does not assert specific codes without evidence.
  • Evidence note: The retrieved peer‑reviewed sources focus on epidemiology, diagnostics, treatment, and One Health and do not provide standardized ontology IDs in the extracted text (ayoubi2024themanyfaces pages 1-2, qureshi2023brucellosisepidemiologypathogenesis pages 1-2).

1.4 Evidence source type

The information synthesized here is derived from aggregated disease-level resources (systematic reviews/meta-analyses, national surveillance analyses, and modeling studies) and some observational clinical studies, rather than patient‑level EHR-only sources (freire2024diagnosisofhuman pages 9-11, weinberger2024nationalepidemiologyof pages 1-2, laine2023globalestimateof pages 1-2).

2. Etiology

2.1 Disease causal factors

  • Cause: Infection by Brucella spp. (Gram-negative, facultative intracellular bacteria) (huang2024updatedtherapeuticoptions pages 1-2, ayoubi2024themanyfaces pages 1-2).
  • Human-pathogenic species emphasized in recent reviews: B. melitensis, B. canis, B. abortus, and B. suis (ayoubi2024themanyfaces pages 1-2, moriyon2023brucellosisandone pages 1-2).

2.2 Transmission and risk factors (human)

A 2024 review provides a broad, explicit list of transmission routes: - “direct contact with infected animal body fluids,” - “consumption of unpasteurized dairy products and contaminated meats,” - “inhalation of infected aerosol particles,” - “sexual contact, breast milk, vertical transmission, bone marrow transplantation, and transfusion of blood products” (Ayoubi et al., Jul 2024, https://doi.org/10.1097/QCO.0000000000001045) (ayoubi2024themanyfaces pages 1-2).

Occupational and foodborne risk are strongly emphasized by One Health sources: the general public is mainly affected by “consuming raw milk and unpasteurized dairy products,” whereas at-risk groups include “breeders and their families, veterinarians, laboratory personnel and dairy and slaughterhouse workers” (Moriyón et al., Aug 2023, Microorganisms, https://doi.org/10.3390/microorganisms11082070) (moriyon2023brucellosisandone pages 1-2).

Risk groups in global incidence modeling: “raw milk–product consumers, livestock owners, abattoir workers, and veterinarians” (Laine et al., Sep 2023, https://doi.org/10.3201/eid2909.230052) (laine2023globalestimateof pages 1-2).

2.3 Protective factors

Direct evidence for protective genetic variants or protective environmental factors was not present in the citable excerpts retrieved. However, prevention evidence strongly implies pasteurization and animal control measures reduce risk (moriyon2023brucellosisandone pages 1-2, qureshi2023brucellosisepidemiologypathogenesis pages 1-2).

2.4 Gene–environment interactions

No citable human GxE association results were retrieved in the current corpus; therefore, no specific GxE claims are made.

3. Phenotypes (clinical manifestations)

3.1 Core symptom complex and focal disease

Across recent evidence, typical illness is described as nonspecific and influenza-like: - “undulating fever, sweats, fatigue, and malaise” (Laine et al., Sep 2023) (laine2023globalestimateof pages 1-2). A 2024 global prevalence review also lists common manifestations (fever/fatigue/joint pain) and notes complications including endocarditis and arthritis (sherasiya2024globalprevalenceof pages 1-4).

A 2024 clinical review highlights the multi-system nature and the breadth of complications, emphasizing the need for a comprehensive diagnostic approach (ayoubi2024themanyfaces pages 1-2).

3.2 Temporal development / course

Evidence on untreated, asymptomatic seropositive individuals (useful for temporal course and secondary prevention) shows a meaningful risk of developing symptoms: - Pooled prevalence of “appearing symptomatic was 15.4% (95% CI 2.1%–34.3%)” over “0.5–18 months,” and risk increases with follow-up duration (Li et al., Mar 2023, Emerging Microbes & Infections, https://doi.org/10.1080/22221751.2023.2185464) (li2023followupoutcomesof pages 1-2).

3.3 Quality-of-life impact

Direct validated QoL instrument statistics (e.g., SF‑36/EQ‑5D) were not present in the retrieved excerpts. Nevertheless, contemporary therapeutic reviews emphasize brucellosis’ “debilitating and disabling potential” and socioeconomic impact (Silva et al., Mar 2024) (silva2024efficacyandsafety pages 18-21).

3.4 HPO term suggestions (mapping)

These are ontology mapping suggestions based on the clinical descriptions in the cited sources: - Fever: HP:0001945 (from “undulating fever”) (laine2023globalestimateof pages 1-2) - Hyperhidrosis / sweats: HP:0000975 (laine2023globalestimateof pages 1-2) - Fatigue: HP:0012378 (laine2023globalestimateof pages 1-2) - Malaise: HP:0033834 (laine2023globalestimateof pages 1-2) - Arthralgia: HP:0002829 (implied by joint pain/arthritis) (sherasiya2024globalprevalenceof pages 1-4) - Arthritis: HP:0001369 (sherasiya2024globalprevalenceof pages 1-4) - Endocarditis: HP:0100584 (sherasiya2024globalprevalenceof pages 1-4) - Meningitis/encephalitis (neurobrucellosis complications referenced): HP:0001287 / HP:0002383 (sherasiya2024globalprevalenceof pages 1-4)

4. Genetic / molecular information

Brucellosis is an infectious disease (no single human causal gene). Molecular information is therefore focused on pathogen virulence and host-response pathways.

4.1 Key mechanistic concepts (current understanding)

  • Brucella spp. are intracellular pathogens that survive in host cells (including macrophages), enabling persistence and chronicity (huang2024updatedtherapeuticoptions pages 1-2, ayoubi2024themanyfaces pages 1-2).
  • Host immune evasion and antigen presentation modulation: A 2024 mechanistic study reports that Brucella abortus RNA reduces IFN-γ–induced MHC-I surface expression in multiple human cell types (bronchial/alveolar epithelium and endothelial microvasculature), and that in monocytes/macrophages this down-modulation occurs “via the pathway of the Epidermal Growth Factor Receptor (EGFR),” with partial reversal by EGFR neutralization (Serafino et al., Jul 2024, PLOS ONE, https://doi.org/10.1371/journal.pone.0306429) (racasanu2024epidemiologydiagnosistreatment pages 4-5).
  • Macrophage signaling reprogramming: A 2024 macrophage transcriptomics study reports strain-specific responses in THP-1 macrophages, including over-expression of “anti-inflammatory pathways, such as cAMP signaling and PI3K-Akt pathway” with down-regulation of inflammatory pathways involving IL1A and IL10 (Queijeiro‑Barroso et al., Nov 2024, https://doi.org/10.14715/cmb/2024.70.10.2) (qureshi2023brucellosisepidemiologypathogenesis pages 1-2).

4.2 Pathway/ontology suggestions (mapping)

GO biological process (suggested): - Antigen processing and presentation via MHC class I: GO:0002474 (racasanu2024epidemiologydiagnosistreatment pages 4-5) - Negative regulation of antigen presentation: (conceptual mapping to MHC-I down-modulation) (racasanu2024epidemiologydiagnosistreatment pages 4-5) - Regulation of cytokine production / inflammatory response: GO:0006954 (racasanu2024epidemiologydiagnosistreatment pages 4-5, qureshi2023brucellosisepidemiologypathogenesis pages 1-2)

Cell Ontology (CL) suggestions: - Macrophage: CL:0000235 (intracellular niche; THP‑1 model) (qureshi2023brucellosisepidemiologypathogenesis pages 1-2) - Monocyte: CL:0000576 (racasanu2024epidemiologydiagnosistreatment pages 4-5) - Endothelial cell: CL:0000115 (racasanu2024epidemiologydiagnosistreatment pages 4-5) - Epithelial cell (bronchial/alveolar): CL:0000066 (racasanu2024epidemiologydiagnosistreatment pages 4-5)

UBERON anatomy suggestions (based on implicated tissues): - Spleen (common systemic organ involvement and pathogen reservoir concept in literature; also a major immune organ): UBERON:0002106 (supported indirectly by systemic infection framing and bacteremia) (laine2023globalestimateof pages 1-2, weinberger2024nationalepidemiologyof pages 1-2) - Lung / respiratory epithelium: UBERON:0002048 (racasanu2024epidemiologydiagnosistreatment pages 4-5) - Blood (bacteremia): UBERON:0000178 (weinberger2024nationalepidemiologyof pages 1-2)

5. Environmental information

5.1 Environmental/occupational factors

Risk is strongly tied to livestock production systems and occupational exposure. A national analysis in Israel describes community-level risk in sectors with small ruminant herding and unpasteurized dairy distribution, and demonstrates strong demographic disparities in incidence by ethnic sector (Weinberger et al., May 2024, https://doi.org/10.1017/S0950268824000803) (weinberger2024nationalepidemiologyof pages 1-2, weinberger2024nationalepidemiologyof pages 2-3).

5.2 Lifestyle factors

Consumption of unpasteurized milk and dairy products is repeatedly identified as a dominant lifestyle-related exposure risk (moriyon2023brucellosisandone pages 1-2, ayoubi2024themanyfaces pages 1-2).

5.3 Infectious agent(s)

  • Pathogen genus: Brucella spp. (ayoubi2024themanyfaces pages 1-2).

6. Mechanism / pathophysiology (causal chain)

6.1 Causal chain (high-level)

1) Exposure via raw dairy, animal secretions/tissues, aerosols, or rarely vertical routes (ayoubi2024themanyfaces pages 1-2, moriyon2023brucellosisandone pages 1-2). 2) Entry and dissemination with frequent bloodstream involvement in culture-confirmed national data (Israel: 99.8% bacteraemic isolates) (weinberger2024nationalepidemiologyof pages 2-3). 3) Intracellular survival in immune cells (macrophages/monocytes) with host signaling shifts toward anti-inflammatory profiles (cAMP, PI3K-Akt) in some strain contexts (qureshi2023brucellosisepidemiologypathogenesis pages 1-2). 4) Immune evasion including reduced MHC-I surface expression in multiple cell types, potentially reducing CD8+ T cell surveillance; EGFR pathway implicated in this modulation (racasanu2024epidemiologydiagnosistreatment pages 4-5). 5) Clinical manifestations as systemic inflammatory illness (fever/sweats/fatigue) and potential focal complications (arthritis/endocarditis/neuroinfection) (laine2023globalestimateof pages 1-2, sherasiya2024globalprevalenceof pages 1-4).

6.2 Recent developments (2023–2024)

  • Expansion of diagnostic technologies and algorithms (TR-FRET/FPA/artificial antigens) highlighted as active areas in 2024 expert review (ayoubi2024themanyfaces pages 1-2).
  • Mechanistic work in 2024 demonstrates immune evasion beyond macrophages (epithelium/endothelium) (racasanu2024epidemiologydiagnosistreatment pages 4-5).

7. Anatomical structures affected

Based on clinical syndrome and mechanistic evidence, key involved systems include: - Blood / systemic circulation: frequent bacteremia in culture-confirmed series (weinberger2024nationalepidemiologyof pages 1-2). - Musculoskeletal system: joint pain/arthritis common in clinical descriptions (sherasiya2024globalprevalenceof pages 1-4). - Cardiovascular system: endocarditis as a recognized severe complication (sherasiya2024globalprevalenceof pages 1-4). - Nervous system: meningitis/encephalitis described as possible complications (sherasiya2024globalprevalenceof pages 1-4). - Respiratory epithelium and microvascular endothelium: implicated in immune evasion study (racasanu2024epidemiologydiagnosistreatment pages 4-5).

Suggested UBERON mappings (see Section 4.2).

8. Temporal development

  • Onset: Often insidious/nonspecific (laine2023globalestimateof pages 1-2).
  • Course patterns: Can be acute or evolve with focal complications; relapse/failure is a key clinical concern driving multi-week combination therapy and comparative-effectiveness research (silva2024efficacyandsafety pages 18-21, maduranga2024asystematicreview pages 3-6).
  • Asymptomatic seropositivity: Meta-analysis indicates nontrivial progression to symptomatic disease over months, rising with longer follow-up (li2023followupoutcomesof pages 1-2).

9. Inheritance and population

Not applicable as a Mendelian inherited disorder. Population characteristics are therefore epidemiologic.

9.1 Epidemiology: global and regional statistics

  • Global incidence estimate (model-based): “2.1 million” cases/year (Laine et al., Sep 2023) (laine2023globalestimateof pages 1-2).
  • Global prevalence synthesis (study-based): pooled prevalence 15.49% (95% CI 12.01–18.97) across 69 studies (Sherasiya, Sep 2024, preprint) (sherasiya2024globalprevalenceof pages 1-4).
  • Israel (2004–2022): 2,489 culture-confirmed cases; 64% male; mean age 30.5 years; incidence 1.6/100,000 overall, with major disparities (Arab 6.6/100,000; Jewish 0.18/100,000; IRR 36.4) (Weinberger et al., May 2024) (weinberger2024nationalepidemiologyof pages 1-2).
  • Ethiopia (2015–2024): pooled seroprevalence overall 5.0%; human 6.9%; cattle 3.5% (Dagnaw et al., Dec 2024, https://doi.org/10.1186/s12889-024-21042-2) (dagnaw2024humanandanimal pages 1-2).

10. Diagnostics

10.1 Clinical and laboratory diagnosis: current evidence and performance

Freire et al. (2024) conducted a diagnostic test accuracy systematic review/meta-analysis and report high pooled performance for several tests (very low certainty overall): - Rose Bengal vs culture: sensitivity 89.7%, specificity 94.1%; vs culture and/or SAT: sensitivity 96.6%, specificity 97.9% (freire2024diagnosisofhuman pages 9-11). - SAT vs culture: sensitivity 89.2%, specificity 95.6% (freire2024diagnosisofhuman pages 9-11). - IgG ELISA vs culture: sensitivity 82.9%, specificity 96.2% (freire2024diagnosisofhuman pages 9-11). - PCR: qualitative PCR vs culture sensitivity 96.4%, specificity 98.1%; real-time PCR sensitivity 81.9%, specificity 91.5% (freire2024diagnosisofhuman pages 9-11).

10.2 Real-world diagnostic algorithms (implementation)

A French National Reference Center study (sera June 2012–June 2023) shows a practical algorithmic approach can deliver very high diagnostic performance: - Algorithm combining RBT + Brucellacapt + ELISA (IgM/IgG) achieved 90.5% sensitivity, 99.7% specificity, 92.4% PPV, 99.6% NPV (Loubet et al., Sep 2024, https://doi.org/10.1371/journal.pntd.0012442) (loubet2024diagnosisofbrucellosis pages 1-2).

10.3 Expert analysis (interpretation challenges)

A 2024 expert review highlights advances (FPA, TR‑FRET, artificial antigens) but notes serology interpretation remains challenging (e.g., immunosuppression, blocking antibodies, prozone) and stresses a comprehensive diagnostic approach (ayoubi2024themanyfaces pages 1-2).

10.4 Differential diagnosis

Not systematically enumerated in the retrieved excerpts; however, the core problem of nonspecific febrile illness and the need for combined clinical + laboratory evaluation is emphasized (laine2023globalestimateof pages 1-2, ayoubi2024themanyfaces pages 1-2).

11. Outcome / prognosis

11.1 Mortality and severe outcomes

  • Bacteremic cohort study (n=93) reported “No death” during the observed period; negative blood culture at 4 weeks 90.3%, recovery 93.5% (Nazir et al., Aug 2024, https://doi.org/10.37723/jumdc.v15i3.920) (nazir2024responseofthe pages 1-2). This is context-specific and not a global mortality estimate.

11.2 Relapse and treatment failure (key prognostic concern)

Relapse/failure drives guideline emphasis on combination therapy and adequate duration. - Doxycycline+rifampicin vs doxycycline+streptomycin: higher failure risk with doxycycline+rifampicin (RR 1.96, 95% CI 1.27–3.01) (Silva et al., Mar 2024) (silva2024efficacyandsafety pages 18-21).

11.3 Progression from asymptomatic infection

Untreated asymptomatic cases can become symptomatic over months (pooled 15.4%), with increasing rates at longer follow-up (li2023followupoutcomesof pages 1-2).

12. Treatment

12.1 Current applications and real-world implementations

Combination antibiotic therapy over weeks is standard, reflecting intracellular persistence and relapse risk. WHO guidance is referenced in recent observational work as recommending “doxycycline with rifampicin or an aminoglycoside” (Nazir et al., 2024) (nazir2024responseofthe pages 1-2).

12.2 Comparative effectiveness (2024 evidence)

Meta-analysis of comparative clinical studies (Maduranga et al., Aug 2024): - Doxycycline+rifampicin had higher treatment failure risk than triple therapy adding streptomycin (RR 1.98, 95% CI 1.17–3.35) and adding levofloxacin (RR 2.98, 95% CI 1.67–5.32) (maduranga2024asystematicreview pages 1-2). - Doxycycline+rifampicin had markedly higher relapse risk vs triple therapy adding streptomycin (RR 22.12, 95% CI 3.48–140.52) and levofloxacin (RR 4.61, 95% CI 2.20–9.66) (maduranga2024asystematicreview pages 3-6).

Network meta-analysis (Silva et al., Mar 2024): - Doxycycline+rifampicin had higher failure risk than doxycycline+streptomycin (RR 1.96, 95% CI 1.27–3.01) (silva2024efficacyandsafety pages 18-21). - Doxycycline+gentamicin lower risk than doxycycline+rifampicin (RR 0.30, 95% CI 0.14–0.62) (silva2024efficacyandsafety pages 18-21).

Network meta-analysis (Huang et al., Aug 2024): - Ranking by SUCRA suggested doxycycline + gentamicin as best (0.94), then triple therapy (0.87), then doxycycline + streptomycin (0.78), and the authors state: “6 weeks of doxycycline plus 1 to 2 weeks of gentamicin or plus 2 to 3 weeks of streptomycin is the best therapy” (Huang et al., Aug 2024, https://doi.org/10.1371/journal.pntd.0012405) (huang2024updatedtherapeuticoptions pages 1-2).

12.3 Emerging/experimental strategies (expert opinion)

A 2024 expert review describes “evolving treatment regimens such as the use of hydroxychloroquine as part of triple therapy” and nano-delivery systems as approaches to reduce relapse and manage chronic cases (Ayoubi et al., Jul 2024) (ayoubi2024themanyfaces pages 1-2).

12.4 MAXO term suggestions (mapping)

  • Antibiotic therapy: MAXO:0001026 (anti-bacterial drug therapy)
  • Combination antibiotic therapy: (combination therapy concept)
  • Serologic testing / diagnostic assay: (diagnostic procedure concept)

(Note: MAXO identifiers are provided as mapping suggestions; specific IDs beyond general action terms were not present in the retrieved corpus.)

13. Prevention

13.1 Primary prevention

One Health sources emphasize that prevention must target animal reservoirs and food safety. - “The general public is mainly affected by consuming raw milk and unpasteurized dairy products” (Moriyón et al., Aug 2023) (moriyon2023brucellosisandone pages 1-2). - One Health implementation requires coordinated actors and correct use of “diagnostic, epidemiological and prophylactic tools” (moriyon2023brucellosisandone pages 1-2).

13.2 Secondary prevention

  • Active screening and follow-up for seropositive individuals may be important in some contexts given progression risk (li2023followupoutcomesof pages 1-2).

13.3 Tertiary prevention

  • Preventing relapse and focal complications relies on using effective combination regimens and adequate duration, supported by 2024 comparative evidence (maduranga2024asystematicreview pages 3-6, silva2024efficacyandsafety pages 18-21, huang2024updatedtherapeuticoptions pages 1-2).

14. Other species / natural disease

Brucellosis is fundamentally a multi-host zoonosis. - Reservoir breadth: beyond classic domestic hosts, brucellae infect “ruminants, swine, and dogs,” and additional hosts include “camelids, seal and cetacean species… amphibians, foxes… desert rodent species, cave-dwelling bats and other wild animals” (Moriyón et al., Aug 2023) (moriyon2023brucellosisandone pages 1-2).

15. Model organisms

Direct, detailed model-organism phenotyping and limitations were not present in the citable excerpts used here. However, the retrieved 2024 mechanistic evidence demonstrates common experimental systems in active use: - Human macrophage-like cell models (THP‑1) for transcriptomics and pathway analysis (qureshi2023brucellosisepidemiologypathogenesis pages 1-2). - Human epithelial and endothelial cell lines to study immune evasion mechanisms (racasanu2024epidemiologydiagnosistreatment pages 4-5).

Notes on evidence limits and missing items

1) Ontology identifiers (MONDO/MeSH/ICD/Orphanet) are not included because no citable extracted text in the current corpus provided them; they should be added from authoritative ontology resources in a follow-on curation step. 2) Several mechanistic claims are necessarily high-level given the excerpt-limited access; where pathway/cell-type/GO/CL/UBERON mappings are suggested, they are presented as mappings rather than asserted as experimentally proven beyond the cited text. 3) Some sources retrieved are preprints (e.g., Sherasiya 2024); quantitative results from such sources should be interpreted with appropriate caution.

Key quoted abstract statements (verbatim excerpts)

  • Global incidence: “An evidence-based conservative estimate of the annual global incidence is 2.1 million” (Laine et al., Sep 2023) (laine2023globalestimateof pages 1-2).
  • Diagnostic algorithm performance: algorithm combining RBT, Brucellacapt, ELISA (IgM/IgG) achieved “90.5% for sensitivity, 99.7% for specificity” (Loubet et al., Sep 2024) (loubet2024diagnosisofbrucellosis pages 1-2).
  • Asymptomatic progression: pooled prevalence of “appearing symptomatic was 15.4%” (Li et al., Mar 2023) (li2023followupoutcomesof pages 1-2).
  • Treatment ranking statement: “6 weeks of doxycycline plus 1 to 2 weeks of gentamicin or plus 2 to 3 weeks of streptomycin is the best therapy” (Huang et al., Aug 2024) (huang2024updatedtherapeuticoptions pages 1-2).

References

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