Septicemic plague is the bloodstream form of plague: Yersinia pestis enters the blood, produces systemic infection with dysregulated inflammation, and can cause disseminated intravascular coagulation, purpura, and rapidly fatal multi-organ dysfunction.
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name: Septicemic Plague
creation_date: "2026-09-25T15:30:29Z"
category: Infectious Disease
description: >-
Septicemic plague is the bloodstream form of plague: Yersinia pestis enters the
blood, produces systemic infection with dysregulated inflammation, and can cause
disseminated intravascular coagulation, purpura, and rapidly fatal multi-organ
dysfunction.
disease_term:
preferred_term: septicemic plague
term:
id: MONDO:0005956
label: septicemic plague
parents:
- Plague
notes: >-
Lump/split decision: septicemic plague is kept as a standalone entry because
MONDO assigns it a distinct term (MONDO:0005956) and this entry curates the
Y. pestis immune-evasion -> bloodstream-infection -> dysregulated-inflammation
-> DIC mechanism that the Septicemic has_subtypes row on Plague.yaml does not
carry. The Plague entry's Septicemic subtype row cross-references this entry.
Bubonic plague is now also curated as Bubonic_Plague (MONDO:0001112), and
pneumonic plague as Pneumonic_Plague (MONDO:0001024).
infectious_agent:
- name: Yersinia pestis
infectious_agent_term:
preferred_term: Yersinia pestis
term:
id: NCBITaxon:632
label: Yersinia pestis
description: >-
Gram-negative plague bacillus that can produce bloodstream infection in the
septicemic form of plague.
evidence:
- reference: PMID:12951845
reference_title: "Yersinia pestis and the plague."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
quote_role: REVIEW_SYNTHESIS
snippet: >-
Yersinia pestis is the cause of plague, an illness that may manifest in bubonic,
pneumonic, or septicemic form.
explanation: >-
Establishes Y. pestis as the causative agent of the septicemic clinical form of
plague.
classifications:
harrisons_chapter:
- classification_value: INFECTIOUS_DISEASES
evidence:
- reference: PMID:12951845
reference_title: "Yersinia pestis and the plague."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
quote_role: REVIEW_SYNTHESIS
snippet: >-
Yersinia pestis is the cause of plague, an illness that may manifest in
bubonic, pneumonic, or septicemic form.
explanation: >-
Septicemic plague is a bacterial infectious form of plague.
pathophysiology:
- name: Yersinia pestis Innate Immune Evasion
description: >-
After flea-to-mammal transmission, Y. pestis uses lipid A remodeling and
type III secretion system Yop effectors to blunt TLR4-mediated innate
recognition and phagocytic-cell signaling.
biological_scale: CELLULAR
cell_types:
- preferred_term: macrophage
term:
id: CL:0000235
label: macrophage
- preferred_term: neutrophil
term:
id: CL:0000775
label: neutrophil
biological_processes:
- preferred_term: innate immune response
modifier: DECREASED
term:
id: GO:0045087
label: innate immune response
- preferred_term: phagocytosis
modifier: DECREASED
term:
id: GO:0006909
label: phagocytosis
downstream:
- target: Systemic Yersinia pestis Bacteremia
causal_link_type: DIRECT
description: >-
Early immune evasion lets Y. pestis proliferate and disseminate into blood.
evidence:
- reference: PMID:23745121
reference_title: "Structural Modifications of Bacterial Lipopolysaccharide that Facilitate Gram-Negative Bacteria Evasion of Host Innate Immunity."
supports: SUPPORT
evidence_source: OTHER
snippet: >-
This alteration of lipid A forms following transmission of Y. pestis from
fleas to humans contributes predominantly to the virulence of this bacterium
over other virulence factors.
explanation: >-
Identifies temperature-dependent Y. pestis lipid A remodeling as the
predominant virulence contributor for host innate-immune evasion.
- reference: PMID:15847602
reference_title: "Yersinia outer proteins: role in modulation of host cell signaling responses and pathogenesis."
supports: SUPPORT
evidence_source: OTHER
snippet: >-
Innate and adaptive immune responses are thwarted as a consequence of Yop
activities.
explanation: >-
Establishes that type III secretion system-delivered Yop effectors block host
immune signaling in pathogenic Yersinia, including Y. pestis.
- name: Systemic Yersinia pestis Bacteremia
description: >-
Y. pestis enters and proliferates within the bloodstream as primary septicemic
plague or after dissemination from a regional lymph-node focus.
biological_scale: ORGANISM
locations:
- preferred_term: blood
term:
id: UBERON:0000178
label: blood
downstream:
- target: Dysregulated Systemic Inflammatory Response
causal_link_type: DIRECT
description: >-
Bloodstream Y. pestis infection triggers systemic inflammatory injury and
clinical sepsis.
evidence:
- reference: PMID:16943764
reference_title: "Human plague--four states, 2006."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Five (38%) patients had primary septicemic plague, and the remaining eight
(62%) had bubonic plague.
explanation: >-
A CDC human case series documents primary septicemic (bloodstream) plague as
a distinct presentation, here 38% of reported U.S. cases.
- reference: PMID:15207311
reference_title: "Plague."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
quote_role: REVIEW_SYNTHESIS
snippet: >-
Bubonic disease, pneumonic plague, and septicemic plague are seen in addition to
a number of other less common manifestations.
explanation: >-
Supports septicemic plague as a distinct clinical form within the Y. pestis
disease spectrum.
- name: Dysregulated Systemic Inflammatory Response
description: >-
Bloodstream plague produces systemic inflammation and sepsis physiology that can
progress to organ dysfunction and death.
biological_scale: ORGANISM
cell_types:
- preferred_term: monocyte
term:
id: CL:0000576
label: monocyte
biological_processes:
- preferred_term: inflammatory response
modifier: INCREASED
term:
id: GO:0006954
label: inflammatory response
downstream:
- target: Disseminated Intravascular Coagulation
causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
description: >-
Septicemic plague can produce coagulation failure with disseminated
intravascular coagulation.
- target: Sepsis
causal_link_type: DIRECT
description: >-
Bloodstream Y. pestis infection manifests as sepsis in the septicemic form.
- target: Fever
causal_link_type: DIRECT
description: >-
The systemic proinflammatory response produces fever.
evidence:
- reference: PMID:17429414
reference_title: "Study of proinflammatory responses induced by Yersinia pestis in human monocytes using cDNA arrays."
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
intracellular infection of human monocytes with Y. pestis results in a
strong inflammatory response at early time periods
explanation: >-
Human-monocyte transcriptional profiling shows Y. pestis triggers a strong
early proinflammatory response, grounding the monocyte and inflammatory-response
bindings on this node.
- reference: PMID:25643450
reference_title: "[Yersinia pestis and plague - an update]."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
quote_role: REVIEW_SYNTHESIS
snippet: >-
Without antibacterial therapy, the disease is associated with a high case
fatality rate, ranging from 40% (bubonic plague) to nearly 100% (septicemic
and pneumonic plague).
explanation: >-
Supports the fulminant systemic severity of the septicemic form downstream of
bloodstream Y. pestis infection.
phenotypes:
- name: Sepsis
category: Constitutional
phenotype_term:
preferred_term: Sepsis
term:
id: HP:0100806
label: Sepsis
evidence:
- reference: PMID:16943764
reference_title: "Human plague--four states, 2006."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Five (38%) patients had primary septicemic plague, and the remaining eight
(62%) had bubonic plague.
explanation: >-
Primary septicemic (bloodstream/sepsis) plague occurred in 38% of this CDC
human case series.
- name: Disseminated Intravascular Coagulation
category: Hematologic
phenotype_term:
preferred_term: Disseminated intravascular coagulation
term:
id: HP:0005521
label: Disseminated intravascular coagulation
sequelae:
- target: Purpura
description: >-
Consumptive coagulopathy produces purpura and cutaneous hemorrhage.
evidence:
- reference: PMID:17429414
reference_title: "Study of proinflammatory responses induced by Yersinia pestis in human monocytes using cDNA arrays."
supports: SUPPORT
evidence_source: IN_VITRO
snippet: >-
downregulation of genes such as thromobomodulin, which may play a role in
coagulation, resulting in disseminated intravascular coagulation, a primary
cause of death in plague infected hosts.
explanation: >-
Human-monocyte data link Y. pestis-induced thrombomodulin downregulation to
the disseminated intravascular coagulation that is a primary cause of death.
- name: Purpura
category: Dermatologic
phenotype_term:
preferred_term: Purpura
term:
id: HP:0000979
label: Purpura
- name: Fever
category: Constitutional
phenotype_term:
preferred_term: Fever
term:
id: HP:0001945
label: Fever
treatments:
- name: Early antibiotic therapy
description: >-
Antimicrobial treatment must be started early because septicemic plague is a
severe form of plague; aminoglycosides, tetracyclines, fluoroquinolones, and
sulfonamides all have reported clinical activity in treated human plague.
treatment_term:
preferred_term: antibiotic therapy
term:
id: NCIT:C15620
label: Antibiotic Therapy
therapeutic_agent:
- preferred_term: streptomycin
term:
id: CHEBI:17076
label: streptomycin
therapeutic_modality: SMALL_MOLECULE
evidence:
- reference: PMID:32435802
reference_title: "Antimicrobial Treatment of Human Plague: A Systematic Review of the Literature on Individual Cases, 1937-2019."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
In addition to aminoglycosides, other classes of antimicrobials including
tetracyclines, fluoroquinolones, and sulfonamides are effective for plague
treatment
explanation: >-
Systematic review of individual treated human plague cases identifying several
active antibiotic classes.
- reference: PMID:32435801
reference_title: "Antimicrobial Treatment Patterns and Illness Outcome Among United States Patients With Plague, 1942-2018."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Mortality differed significantly among those receiving high-efficacy therapy
(9%) and only limited-efficacy therapy (51%).
explanation: >-
Surveillance analysis links prompt high-efficacy antimicrobial therapy to
improved survival in reported U.S. plague cases.
transmission:
- name: Flea-borne and direct animal exposure
description: >-
Y. pestis reaches people by flea bites and by non-vector contact with infected
animal material; direct tissue handling is a recognized route for primary
septicemic plague.
evidence:
- reference: PMID:25643450
reference_title: "[Yersinia pestis and plague - an update]."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
quote_role: REVIEW_SYNTHESIS
snippet: >-
Transmission of Y. pestis to humans occurs by the bite of rat fleas, other
flea vectors or by non vectorial routes, e. g., handling infected animals or
consumption of contaminated food.
explanation: >-
Supports both flea-borne transmission and direct infected-animal handling as
acquisition routes that can seed bloodstream Y. pestis infection.
progression:
- phase: Treated clinical spectrum
notes: >-
In a systematic review of published individual treated plague cases, primary
septicemic plague was less common than primary bubonic or pneumonic plague but
had the highest case fatality among those three presentations.
evidence:
- reference: PMID:32435802
reference_title: "Antimicrobial Treatment of Human Plague: A Systematic Review of the Literature on Individual Cases, 1937-2019."
supports: SUPPORT
evidence_source: HUMAN_CLINICAL
snippet: >-
Most patients had primary bubonic (63%), pneumonic (21%), or septicemic (5%)
plague, with associated case fatality rates of 17%, 27%, and 38%,
respectively.
explanation: >-
Documents the relative frequency and treated case-fatality estimate for primary
septicemic plague among published individual treated plague cases.
Deep research results are used as seeds for research; they do not undergo the same validation as the main records and may contain errors. How we use deep research.
Disease: Septicemic Plague · MONDO ID: MONDO:0005956 · Category: Infectious Disease Causative agent: Yersinia pestis (NCBI:txid632) · ICD-10: A20.7 · ICD-11: 1B93.1 · MeSH: D010931 (Plague)
Septicemic plague is an acute, fulminant bloodstream infection caused by the gram-negative coccobacillus Yersinia pestis. It is the least common but most lethal of the three classical forms of plague. In a systematic review of 762 treated human cases (1937–2019), septicemic plague accounted for only 5% of cases but carried a case-fatality rate (CFR) of 38%, exceeding both bubonic (17%) and pneumonic (27%) forms; untreated, it approaches ~100% fatality (PMID: 32435802, PMID: 25643450). It can arise as primary septicemic plague — fulminant gram-negative sepsis without a palpable bubo, often after handling infected animal tissue — or as secondary septicemic plague when untreated bubonic or pneumonic disease disseminates hematogenously.
The pathophysiology is a coordinated, multi-layered virulence program that first paralyzes innate immunity to permit unchecked bacterial replication, then triggers a destructive inflammatory collapse. Temperature-dependent remodeling of LPS lipid A (from hexa-acylated at the flea's 27 °C to poorly-stimulatory tetra-acylated at the host's 37 °C) blunts TLR4 sensing; a plasmid-encoded type III secretion system (T3SS) injects Yop effectors that block phagocytosis and cytokine production; the F1/Caf1 capsule resists macrophage engulfment; and the Pla plasminogen activator enables dissemination from peripheral tissues. This "pre-inflammatory" phase of silent growth is followed by a "pro-inflammatory" phase — a delayed neutrophil influx and cytokine storm (IL-6, TNF-α, IFN-γ) that fails to control bacteria while driving disseminated intravascular coagulation (DIC), acral gangrene, septic shock, and multi-organ failure.
Survival is overwhelmingly determined by time to effective antibiotics. Among 533 US patients (1942–2018), mortality was 9% with high-efficacy therapy versus 51% with only limited-efficacy therapy (PMID: 32435801). There is no heritable genetic cause, no established human susceptibility gene, and no licensed vaccine for general use, so prevention rests on rodent/flea vector control, exposure avoidance, and post-exposure chemoprophylaxis. This report synthesizes 14 confirmed findings drawn from 42 reviewed papers across all 15 requested sections.
Overview. Septicemic plague is the bloodstream-invasive manifestation of infection by Yersinia pestis, a gram-negative, non-motile, facultatively intracellular coccobacillus of the family Enterobacteriaceae. It is defined clinically by isolation of Y. pestis from blood in a patient without lymphadenopathy (no bubo) — distinguishing primary septicemic plague from bubonic plague — or by hematogenous dissemination of another plague form (secondary septicemic plague) (PMID: 16943764). The recognized clinical forms of plague are subclinical/serologic plague, plague pharyngitis, pestis minor (abortive bubonic), bubonic, septicemic, pneumonic, and plague meningitis (PMID: 9097371).
"Clinical presentations include subclinical plague (positive serology without disease); plague pharyngitis; pestis minor (abortive bubonic plague); bubonic plague; septicemic plague; pneumonic plague; and plague meningitis." — PMID: 9097371
Key identifiers.
| Resource | Identifier |
|---|---|
| MONDO | MONDO:0005956 (septicemic plague) |
| MeSH | D010931 (Plague) |
| ICD-10 | A20.7 (Septicaemic plague); A20 (Plague) |
| ICD-11 | 1B93.1 (Septicaemic plague) |
| NCBI Taxonomy (pathogen) | txid632 (Yersinia pestis) |
| OMIM | Not applicable (infectious, non-Mendelian) |
| Orphanet | Plague is not a classical rare-genetic Orphanet entity |
Synonyms / alternative names. Septicaemic plague; blood plague; Yersinia pestis septicemia; historically part of the "Black Death" (the acral gangrene of DIC gives the blackened appearance).
Data source type. Information for this report is derived from aggregated disease-level resources — systematic reviews, case series, surveillance datasets (CDC/WHO), and experimental animal-model studies — rather than individual EHR data.
Causal factor — infectious only. The sole cause is infection with Yersinia pestis. There is no Mendelian/genetic causation and no established human susceptibility gene; the disease is not heritable (inheritance not applicable) (PMID: 9097371).
Risk factors (environmental/exposure). Documented factors include residence in or travel to endemic foci; occupational and recreational animal contact (veterinarians and assistants, hunters/trappers, wildlife biologists); pet ownership and direct animal-reservoir contact (especially during hunting season); living in a household with an index case; flea bite; handling infected animal tissue (a route that can produce primary septicemic plague); and climatic conditions favoring reservoir/vector abundance (mild winters, cool moist springs, early summers) (PMID: 9097371). Cats are a notable source of respiratory (pneumonic) transmission to humans.
"Other factors that increase risk of infection in endemic areas are occupation-veterinarians and assistants, pet ownership, direct animal-reservoir contact especially during the hunting season, living in households with an index case, and, mild winters, cool moist springs, and early summers." — PMID: 9097371
Immunocompromise. HIV and other immunocompromising conditions can worsen severity/outcome; a 2024 Nigerian case report highlights the potential severity of co-infection in immunocompromised individuals (PMID: 41263683).
Genetic protective factors / gene–environment interactions. No validated human protective alleles or GxE interactions are established for plague susceptibility. (Historical hypotheses linking CCR5-Δ32 or other loci to plague survival remain unproven.)
Septicemic plague presents as fulminant gram-negative sepsis without a palpable bubo: high fever, chills, rigors, prostration, tachycardia, hypotension, and rapid progression to shock, DIC, and multi-organ failure. Acral necrosis/gangrene of digits and nose is a classic late sign (the basis of "Black Death") (PMID: 16943764, PMID: 9097371).
"Five (38%) patients had primary septicemic plague, and the remaining eight (62%) had bubonic plague." — PMID: 16943764
| Phenotype | Type | Onset / progression | Frequency | Suggested HPO |
|---|---|---|---|---|
| Fever, chills | Symptom/sign | Acute (1–7 d incubation), rapidly progressive | Near-universal | HP:0001945 (Fever) |
| Hypotension / septic shock | Clinical sign | Rapid | Common in severe/late disease | HP:0001635 hypotension; HP:0031273 septic shock |
| Disseminated intravascular coagulation | Lab/clinical | Rapid | Characteristic of severe disease | HP:0005521 (DIC) |
| Acral gangrene / necrosis (digits, nose) | Physical manifestation | Late | Classic but not universal | HP:0100758 (Gangrene) |
| Abdominal pain, nausea, vomiting, diarrhea | Symptom | Early/variable | Frequent in septicemic form | HP:0002027; HP:0002018; HP:0002014 |
| Prostration / altered mental status | Symptom/sign | Progressive | Common | HP:0012378 (Fatigue); HP:0001259 (Coma, severe) |
| Thrombocytopenia, leukocytosis | Lab abnormality | Early | Frequent | HP:0001873; HP:0001974 |
| Absence of bubo | Distinguishing feature | — | Defining for primary septicemic | — |
Severity/progression. Severe and progressive; without early antibiotics, the course is fulminant and lethal within days. Quality-of-life impact: acute and life-threatening rather than chronic; survivors of DIC-associated gangrene may require amputation with long-term disability, but there is no chronic/relapsing phase.
Not applicable in the human-host sense. Septicemic plague has no causal human genes, no pathogenic germline/somatic variants, no modifier genes, no disease-specific epigenetic signature, and no chromosomal abnormalities — it is a purely infectious disease.
The relevant "genetics" are those of the pathogen, whose plasmid-encoded virulence genes drive the septicemic phenotype:
| Genetic element | Location | Product / function |
|---|---|---|
| pla | pPCP1 (pKYP1, ~9.5 kb) | Plasminogen activator (Pla): coagulase + fibrinolysin; dissemination (PMID: 8360901) |
| T3SS + yop effectors (yopH, E, O/ypkA, M, J, T), lcrV | pCD1 (pYV, ~70 kb) | Type III secretion; injection of anti-immune effectors (PMID: 15847602, PMID: 24599533) |
| caf1M1A1 operon | pMT1 (~100 kb) | F1 (Caf1) capsular antigen; antiphagocytic (PMID: 35358289, PMID: 19103769) |
| lipid A biosynthesis genes | chromosome | Temperature-dependent lipid A acylation; TLR4 evasion (PMID: 23745121) |
Y. pestis is a recently emerged, genetically monomorphic clone of Y. pseudotuberculosis. Rare naturally occurring F1-negative (caf-negative) strains remain virulent but evade F1-based diagnostics (PMID: 35320275).
PHASE 1 — IMMUNE EVASION (pre-inflammatory) PHASE 2 — CYTOKINE STORM (pro-inflammatory)
[37°C lipid A shift -> TLR4 blind] [~48 h: neutrophil influx]
[T3SS/Yops -> block phagocytosis + cytokines] ==> [IL-6, TNF-a, IFN-g surge]
[F1 capsule -> antiphagocytic] [tissue destruction, DIC]
[Pla -> dissemination] [septic shock, MOF, gangrene]
silent bacterial growth spleen->liver->blood host collapse
"Pneumonic plague progression is biphasic, with an initial pre-inflammatory phase facilitating bacterial growth in the absence of host inflammation, followed by a pro-inflammatory phase marked by extensive neutrophil influx, an inflammatory cytokine storm, and severe tissue destruction." — PMID: 24098126
"Effector Yops function to counteract multiple signaling responses in the infected host cell ... Innate and adaptive immune responses are thwarted as a consequence of Yop activities." — PMID: 15847602
Upstream vs downstream. Upstream = LPS remodeling, T3SS/Yops, F1 capsule, Pla (immune evasion + dissemination). Downstream = cytokine storm, DIC, shock, organ failure. Blunting the downstream inflammation (intranasal fluticasone) reduced IL-6, neutrophil infiltration, bacterial burden, and improved antibiotic-treated survival — evidence the storm itself is pathogenic (PMID: 34780267).
Suggested ontology terms. GO:0006955 (immune response), GO:0006954 (inflammatory response), GO:0042742 (defense response to bacterium), GO:0030193 (regulation of blood coagulation), GO:0006909 (phagocytosis). Cell types: CL:0000235 (macrophage), CL:0000775 (neutrophil), CL:0000115 (endothelial cell). CHEBI:16412 (lipopolysaccharide).
"Late-stage pneumonic plague is difficult to treat, as antibiotics must be delivered within 24 h after onset of symptoms to be effective." — PMID: 34780267
Epidemiology. Between 2010 and 2019 the six countries reporting the most human plague cases were Madagascar, DR Congo, Uganda, Peru, Tanzania, and the USA, totaling 4,547 cases with 17% mortality (786 deaths) (PMID: 40022523). Y. pestis is a WHO priority pathogen with epidemic/pandemic potential, endemic in rodent reservoirs across Africa, Asia, North America, and South America; Madagascar records a large share of annual global cases (PMID: 33264458, PMID: 38935608). Septicemic plague constitutes ~5% of plague cases (PMID: 32435802).
"Between 2010 and 2019, the six countries with the most reported human cases of Yersinia pestis infection ... were Madagascar, the Congo, Uganda, Peru, Tanzania, and the USA, with a total of 4,547 cases with a mortality rate of 17% (786 cases)." — PMID: 40022523
Genetic etiology. Not applicable — no inheritance pattern, penetrance, expressivity, anticipation, mosaicism, founder effect, consanguinity role, or carrier frequency; the disease is infectious.
Population demographics. Risk tracks exposure, not ethnicity — rural residents, hunters, and animal handlers in endemic foci are over-represented. Geographic distribution follows enzootic rodent foci (western US, Madagascar, central Asia, Andean South America, sub-Saharan Africa). No strong intrinsic sex bias independent of occupational exposure; all ages are susceptible.
Confirmatory diagnosis rests on three pillars — culture, PCR, and serology — supplemented by rapid antigen tests. For the septicemic form specifically, blood culture and peripheral blood smear (bipolar "safety-pin" gram-negative coccobacilli on Wright/Giemsa/Wayson stain) are central because there is no bubo to aspirate.
| Method | Target/approach | Performance |
|---|---|---|
| Bacterial culture | Isolate Y. pestis from blood/aspirate/sputum (reference standard) | ~65% sensitivity |
| PCR / qPCR | caf1, pla, yopM | ~85% (single); triplex qPCR 100% sens / 82% spec (PMID: 40705833) |
| Serology | Anti-F1 IgG | positive in ~93% of confirmed cases |
| F1 rapid diagnostic test (F1RDT / LFI) | Capsular F1 antigen, point-of-care | On-site 94% sens / 74% spec (PMID: 41389991); Madagascar retrospective 100% sens / 67% spec (PMID: 32000692) |
| Dual-antigen (F1+LcrV) LFI/ELISA | Detects F1-negative strains too | LoD ~1–2 ng/mL (PMID: 35320275) |
| ddPCR (multi-target) | ypo2088, caf1, pla | Superior sensitivity for low-load samples (PMID: 38701065) |
"The sensitivity and specificity of on-site F1RDT were 94% (95% CI, 89.6-97.0) and 74% (95% CI, 68.2-79.3) against RS1" — PMID: 41389991
Genetic/omics testing: not applicable to human diagnosis; pathogen genotyping (MLVA, CRISPR, SNP/WGS) is used for outbreak epidemiology, not patient diagnosis (PMID: 38935608).
Differential diagnosis: other causes of gram-negative sepsis/DIC, meningococcemia, tularemia, anthrax, rickettsioses, and other hemorrhagic febrile illnesses; the epidemiologic exposure history and blood smear morphology are key discriminators. Blind spot: rare F1-negative strains evade F1-based antigen tests — hence dual-antigen assays and PCR backup.
Mortality. Treated septicemic plague CFR is ~38%; untreated it approaches ~100% (PMID: 32435802, PMID: 25643450). The single dominant prognostic factor is time to effective antimicrobial therapy: in 533 US patients, mortality was 9% with high-efficacy therapy vs 51% with limited-efficacy therapy (PMID: 32435801).
"Without antibacterial therapy, the disease is associated with a high case fatality rate, ranging from 40% (bubonic plague) to nearly 100% (septicemic and pneumonic plague)." — PMID: 25643450
"Mortality differed significantly among those receiving high-efficacy therapy (9%) and only limited-efficacy therapy (51%)." — PMID: 32435801
Complications. Septic shock, DIC with purpura and acral gangrene (fingers, toes, nose), ARDS, secondary pneumonic plague (with human-to-human transmission risk), plague meningitis, and multi-organ failure (PMID: 34780267).
Recovery. Binary — death or recovery, with no chronic phase. Survivors of DIC-associated gangrene may require amputation, producing long-term functional disability. Other prognostic factors: delay in diagnosis, older age, immunocompromise (e.g., HIV, PMID: 41263683), and severity of shock/DIC at presentation.
Pharmacotherapy is the mainstay and must be started empirically on clinical suspicion — before laboratory confirmation.
| Drug class | Agents | Notes / NCIT |
|---|---|---|
| Aminoglycosides (first-line) | Streptomycin, gentamicin | Aminoglycoside-treated CFR ~13% vs 20% overall; streptomycin outperformed gentamicin in US data (PMID: 32435801). NCIT:C540 (Gentamicin), NCIT:C839 (Streptomycin) |
| Fluoroquinolones | Ciprofloxacin, levofloxacin | FDA-approved for plague; used in >30% of recent patients. NCIT:C2249 (Ciprofloxacin) |
| Tetracyclines | Doxycycline | Associated with increased survival; oral option. NCIT:C516 (Doxycycline) |
| Others | Chloramphenicol, sulfonamides/TMP-SMX | Chloramphenicol preferred historically for plague meningitis (CNS penetration) |
"Gentamicin use was associated with higher mortality than streptomycin, and aminoglycoside use was linked to higher mortality than for tetracyclines." — PMID: 32435801
Intracellular caveat: during the early facultative-intracellular stage, streptomycin and ciprofloxacin retain efficacy against intracellular Y. pestis, whereas gentamicin and doxycycline are less effective intracellularly — relevant for agent selection (PMID: 21628541).
Supportive care: aggressive management of septic shock, fluid resuscitation, vasopressors, and DIC/coagulopathy management are essential given the fulminant sepsis physiology. Adjunctive anti-inflammatory strategies are experimental — fluticasone improved antibiotic-treated survival in a pneumonic model by dampening the cytokine storm (PMID: 34780267). Surgery: amputation/debridement of gangrenous tissue in survivors. No gene, cell, RNA, or targeted/immuno-therapies apply. No pharmacogenomic considerations are established.
"LcrV, a protein at the tip of type III secretion needles, and F1, the capsular pilus antigen, are both recognized as plague protective antigens. Antibodies against LcrV and F1 interfere with Y. pestis type III injection of host cells." — PMID: 19786842
"More than 20 candidate plague vaccines are in the preclinical phase, with few in early (phase 1) clinical trials." — PMID: 40022523
"Bacteria disseminated from the lungs to peripheral organs, with the largest increases in the spleen, followed by the liver and blood at 72h p.i." — PMID: 19073275
"rats were as sensitive to pneumonic plague as mice, having a similar LD(50) dose by the intranasal and aerosolized routes. Further, we showed direct transmission of plague bacteria from infected to uninfected rats." — PMID: 19073275
Septicemic plague is best understood as a two-act drama of immune subversion followed by immune catastrophe. In Act I, Y. pestis deploys a layered virulence toolkit — temperature-tuned low-TLR4 lipid A, T3SS-delivered Yop effectors, the F1 antiphagocytic capsule, and Pla-driven dissemination — that renders the early innate response blind and impotent, allowing silent exponential growth and hematogenous spread (spleen → liver → blood). In Act II, once bacterial burden is overwhelming, a delayed and futile neutrophil/cytokine storm erupts; it fails to clear the pathogen but ignites DIC, microvascular thrombosis, acral gangrene, septic shock, and multi-organ failure. This framework explains the two clinical hallmarks of the septicemic form — its fulminant tempo (silent growth means patients present already deep into dissemination) and its exceptional lethality (immune paralysis then immune-mediated tissue destruction) — and it explains why time-to-antibiotic is decisive: therapy given before the storm interrupts the cascade, while therapy given after it (>24 h in late disease) cannot reverse established DIC/shock. The finding that anti-inflammatory adjuncts improve antibiotic-treated survival further supports the storm as an independently pathogenic downstream node, and points to combined antimicrobial + immunomodulatory strategies as a rational future direction.
| PMID | Contribution |
|---|---|
| 32435802 | Septicemic plague = 5% of cases, 38% CFR (systematic review, 762 cases) |
| 25643450 | Near-100% untreated fatality; Y. pestis etiology |
| 40022523 | 2010–2019 global epidemiology; vaccine pipeline status |
| 33264458 | Rodent-reservoir endemicity; Madagascar hotspot |
| 8360901 | pla coagulase/fibrinolysin → dissemination/transmission |
| 23745121 | Temperature-dependent lipid A → TLR4 evasion |
| 15847602 | Yop effectors thwart innate + adaptive immunity |
| 24599533 | YopE (anti-phagocytosis), YopJ (cytotoxicity); LcrV antigen |
| 39423229 | Yop-mediated LTB4 suppression delays inflammation |
| 35358289 | F1/Caf1 antiphagocytic capsule |
| 19103769 | Anti-F1 antibodies protective; capsule operon in transmission |
| 16943764 | Primary septicemic plague clinical cluster (US, 2006) |
| 9097371 | Clinical forms; risk factors |
| 32435801 | Therapy efficacy: 9% vs 51% mortality; agent comparisons |
| 24098126 | Biphasic pre-/pro-inflammatory mechanism; macrophage→neutrophil switch |
| 17101642 | Delayed (~48 h) cytokine/chemokine surge; named mediators |
| 19073275 | Rat model; spleen→liver→blood dissemination; transmission |
| 34780267 | 24 h therapeutic window; fluticasone adjunct benefit |
| 41389991 / 32000692 / 40705833 / 35320275 | Diagnostics: F1RDT, triplex qPCR, dual-antigen LFI |
| 19786842 | LcrV + F1 subunit vaccine antigens |
| 21628541 | Intracellular antibiotic efficacy differences |
| 29183475 | Prophylaxis and isolation guidelines |
| 41263683 | Fulminant plague in HIV-positive patient |
Evidence source types: human clinical/surveillance (systematic reviews, case series, RDT field studies), model organism (mouse/rat CO92 studies), and in vitro/molecular (T3SS, F1, Pla, lipid A mechanism papers).
Report compiled from 14 confirmed findings across 42 reviewed papers, covering all 15 requested disease-characteristic sections. Ontology suggestions (MONDO, HPO, GO, CL, UBERON, CHEBI, NCIT, NCBI Taxonomy) are provided inline where applicable.
Checked with linkml-reference-validator 0.3.0rc1.
| Outcome | Count |
|---|---|
| References checked | 30 |
| Resolved | 30 |
| Unresolved (possible confabulation) | 0 |
| Unverifiable | 0 |
| References weighed for topical relevance | 30 |
| On topic | 21 |
| Off topic | 0 |
All extracted references resolved successfully.
Checked with linkml-term-validator 0.4.5, through the ols: adapter.
| Outcome | Count |
|---|---|
| Terms checked | 37 |
| Resolved | 37 |
| Unresolved (possible confabulation) | 0 |
| Obsolete | 0 |
| Unverifiable | 0 |
| Terms whose name was checked | 23 |
| Terms named correctly | 17 |
| Terms named as a different term | 4 |
| Terms whose name is worth a second look | 2 |
These identifiers resolve, so nothing about them looks wrong, and the ontology calls them something unrelated to what the report calls them. That usually means the identifier is not the one the sentence needs:
HP:0005521 (1 mention) - the report calls it "DIC"; HP calls it Disseminated intravascular coagulationUBERON:0002097 (1 mention) - the report calls it "skin/acral tissue"; UBERON calls it skin of bodyNCIT:C2249 (1 mention) - the report calls it "Ciprofloxacin"; NCIT calls it Yttrium Y 90 Monoclonal Antibody MN-14NCIT:C516 (1 mention) - the report calls it "Doxycycline"; NCIT calls it Ganglioside GM2The report's name for these is recognisably related to the term's own name without being one of them. A loose paraphrase reads the same way as a citation of the wrong sibling term - and so does a related synonym, which the ontology records precisely because it names something adjacent rather than the same thing - so these are listed rather than judged:
GO:0005576 (1 mention) - the report calls it "cell surface/extracellular region"; GO calls it extracellular regionGO:0009279 (1 mention) - the report calls it "outer membrane"; GO calls it cell outer membrane