Bubonic Plague

Infectious Disease MONDO:0001112 Pathograph 11 Show in embeddings browser Plague

Bubonic plague is the lymph-node form of plague: Yersinia pestis is usually inoculated into skin by an infected flea, evades early innate killing through its type III secretion system, disseminates to draining lymph nodes, and replicates there to produce the regional lymphadenopathy that defines the bubonic presentation.

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5
Pathophys.
9
Phenotypes
11
Pathograph
1
Medical Actions
1
Deep Research
🏷

Classifications

Harrison's Part
INFECTIOUS DISEASES
⚙

Pathophysiology

5
Flea-Mediated Yersinia pestis Inoculation
Infected fleas transmit Y. pestis from rodent reservoirs and inoculate the bacterium into skin, initiating the usual route to bubonic plague through local survival, hemostatic remodeling, and dissemination to a draining lymph node.
skin UBERON:0002097 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in skin, annotated with skin of body (UBERON:0002097). UBERON:0002097 is an anatomical location from the Uberon multi-species anatomy ontology.
Show evidence (1 reference)
PMID:30940874 SUPPORT REVIEW SYNTHESIS Other
"Plague is a vector-borne disease caused by Yersinia pestis. Transmitted by fleas from rodent reservoirs"
Establishes flea-borne transmission of Y. pestis, the canonical exposure route that seeds bubonic plague.
Type III Secretion-Mediated Innate Immune Evasion
The Y. pestis type III secretion system injects Yop effector proteins into mammalian host cells and suppresses phagocyte defenses, permitting bacterial survival and expansion.
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. neutrophil CL:0000775 Cell Ontology (CL) Relation: this pathophysiological event involves this cell type This pathophysiological event involves neutrophil (CL:0000775). CL:0000775 is a cell type from the Cell Ontology.
phagocytosis GO:0006909 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased phagocytosis (GO:0006909). GO:0006909 is a biological process from the Gene Ontology. ↓ DECREASED innate immune response GO:0045087 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves decreased innate immune response (GO:0045087). GO:0045087 is a biological process from the Gene Ontology. ↓ DECREASED
Show evidence (1 reference)
PMID:24198067 SUPPORT REVIEW SYNTHESIS Other
"Yersinia pestis, the etiologic agent of plague, utilizes a type III secretion system (T3SS) to subvert the defenses of its mammalian hosts."
Supports T3SS-mediated suppression of host defense as a core Y. pestis virulence process.
Pla-Mediated Hemostatic Remodeling
The Pla omptin protease activates human plasminogen and urokinase while inactivating the host fibrinolysis inhibitors alpha-2-antiplasmin and plasminogen activator inhibitor 1, enhancing local fibrinolysis that is thought to promote Y. pestis survival and spread from the dermal inoculation site.
fibrinolysis GO:0042730 Gene Ontology (GO) Relation: this pathophysiological event involves this biological process This pathophysiological event involves increased fibrinolysis (GO:0042730). GO:0042730 is a biological process from the Gene Ontology. ↑ INCREASED
skin UBERON:0002097 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in skin, annotated with skin of body (UBERON:0002097). UBERON:0002097 is an anatomical location from the Uberon multi-species anatomy ontology.
Show evidence (1 reference)
PMID:23898467 SUPPORT REVIEW SYNTHESIS In Vitro
"Pla activates human plasminogen to the serine protease plasmin and activates the physiological plasminogen activator urokinase."
Reviews the Pla activities that couple Y. pestis to host fibrinolysis and hemostatic remodeling.
Draining Lymph Node Colonization
Bacteria reach regional lymph nodes and replicate there; this lymphatic focus is the anatomic process that produces the bubo of bubonic plague.
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
lymph node UBERON:0000029 Uberon multi-species anatomy ontology (UBERON) Relation: this pathophysiological event occurs in this anatomical location This pathophysiological event occurs in lymph node (UBERON:0000029). UBERON:0000029 is an anatomical location from the Uberon multi-species anatomy ontology.
Show evidence (1 reference)
PMID:30940874 SUPPORT REVIEW SYNTHESIS Other
"unrestricted bacterial replication in lymph nodes (bubonic plague) and in lungs (pneumonic plague)"
Supports lymph nodes as the defining replication site of bubonic plague.
Hematogenous Dissemination
Y. pestis can disseminate from the lymphatic focus into the bloodstream, producing systemic plague and sepsis.
⬡

Pathograph

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

Phenotypes

9
Blood 1
Disseminated Intravascular Coagulation HP:0005521 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Disseminated intravascular coagulation (HP:0005521). HP:0005521 is a phenotype from the Human Phenotype Ontology.
Cardiovascular 2
Bubo Lymphadenopathy HP:0002716 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Lymphadenopathy (HP:0002716). HP:0002716 is a phenotype from the Human Phenotype Ontology.
Hypotension HP:0002615 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Hypotension (HP:0002615). HP:0002615 is a phenotype from the Human Phenotype Ontology.
Immune 1
Sepsis HP:0100806 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Sepsis (HP:0100806). HP:0100806 is a phenotype from the Human Phenotype Ontology.
Metabolism 1
Fever 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.
Nervous System 1
Headache 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.
Constitutional 3
Malaise 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.
Gangrene HP:0100758 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Gangrene (HP:0100758). HP:0100758 is a phenotype from the Human Phenotype Ontology.
Chills HP:0025143 Human Phenotype Ontology (HP) Relation: this clinical feature is this phenotype This clinical feature is Chills (HP:0025143). HP:0025143 is a phenotype from the Human Phenotype Ontology.
💊

Medical Actions

1
Early antibiotic therapy
Action: antibiotic therapyNCI Thesaurus (NCIT) Relation: this treatment is this clinical intervention This treatment is antibiotic therapy (NCIT:C15620). NCIT:C15620 is a clinical intervention from the NCI Thesaurus. Ontology label: Antibiotic Therapy NCIT:C15620
Agent: 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. gentamicin CHEBI:759884 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses gentamicin (CHEBI:759884). CHEBI:759884 is a therapeutic agent from Chemical Entities of Biological Interest. ciprofloxacin CHEBI:100241 Chemical Entities of Biological Interest (CHEBI) Relation: this treatment uses this therapeutic agent This treatment uses ciprofloxacin (CHEBI:100241). CHEBI:100241 is a therapeutic agent from Chemical Entities of Biological Interest.
Platform: Small molecule
Antimicrobial treatment must be started early because untreated plague can be rapidly fatal; aminoglycosides, tetracyclines, fluoroquinolones, and sulfonamides all have reported clinical activity in treated human plague.
Show evidence (4 references)
PMID:32435802 SUPPORT REVIEW SYNTHESIS Human Clinical
"In addition to aminoglycosides, other classes of antimicrobials including tetracyclines, fluoroquinolones, and sulfonamides are effective for plague treatment"
Systematic review of individual treated human plague cases identifying several active antibiotic classes.
PMID:29183475 SUPPORT REVIEW SYNTHESIS Other
"Most of the therapeutic guidelines suggest using gentamicin or streptomycin as first line therapy with ciprofloxacin as optional treatment."
Identifies gentamicin and streptomycin as commonly recommended first-line agents and ciprofloxacin as an optional plague treatment.
PMID:21628541 SUPPORT In Vitro
"For THP-1 cells, streptomycin and ciprofloxacin had comparable efficacies for intra- and extracellular Y. pestis, but the MBCs for chloramphenicol, gentamicin, doxycycline, and amoxicillin were two-, three-, four-, and five 2-fold serial dilutions greater, respectively, for intracellular than..."
Supports activity of specific plague antibiotics against intracellular Y. pestis in macrophage-like cells, an early host niche for the organism.
+ 1 more reference
🔬

Diagnosis

1
Bubo Aspirate Culture, qPCR, Serology, and F1 Antigen Testing
Bubo aspirates from suspected bubonic plague cases can be tested by culture, PCR, and F1-antigen rapid diagnostic testing, with complementary blood serology; a triplex qPCR assay can target the Y. pestis caf1, pla, and yopM plasmid genes in a single assay.
Results: Triplex qPCR targeting caf1, pla, and yopM reached 100% sensitivity and 82% specificity against bacteriology in a Madagascar evaluation; on-site F1RDT in the IMASOY trial reached 94% sensitivity and 74% specificity against the routine culture/PCR reference standard.
Show evidence (4 references)
PMID:40705833 SUPPORT Human Clinical
"The assay targeted three genes: caf1, pla, and yopM, located on the plasmids pMT1, pPCP1, and pCD1, respectively."
Identifies the three Y. pestis plasmid targets used by the evaluated triplex qPCR diagnostic assay.
PMID:40705833 SUPPORT Human Clinical
"Using bacteriology technique as the reference standard, the triplex qPCR demonstrated a sensitivity of 100% (89-100%) and a specificity of 82%."
Gives the test performance of the triplex qPCR assay against bacteriology in a Madagascar clinical-sample evaluation.
PMID:41389991 SUPPORT Human Clinical
"Bubo aspirates from patients (all ages) with suspected bubonic plague enrolled into the IMASOY trial (NCT04110340) underwent routine laboratory diagnosis complemented with serology to measure IgG F1 antibodies from blood samples taken on days 1, 11, and 21."
Establishes that culture, PCR, and F1 serology were used in a bubo-aspirate-centered diagnostic workflow for suspected bubonic plague.
+ 1 more reference
📈

Progression

1
Acute untreated disease
Untreated bubonic plague can progress to death in less than a week.
Show evidence (1 reference)
PMID:30940874 SUPPORT REVIEW SYNTHESIS Other
"the rapid onset of death in the absence of antibiotic treatment (less than a week for bubonic plague and <48 h for pneumonic plague)"
Supports a short untreated time course for bubonic plague.
📊

Prevalence

2
Published individual treated plague cases, 1937-2019
Cases In Literature Unknown
Primary bubonic plague accounted for 63% of 762 published treated plague cases and had 17% case fatality among primary bubonic cases.
Show evidence (1 reference)
PMID:32435802 SUPPORT REVIEW SYNTHESIS Human Clinical
"Most patients had primary bubonic (63%), pneumonic (21%), or septicemic (5%) plague, with associated case fatality rates of 17%, 27%, and 38%, respectively."
Supports primary bubonic plague as the most frequent clinical form among published treated plague cases in the systematic review.
Six leading plague-reporting countries, 2010-2019
Cases In Literature Unknown
Madagascar, Congo, Uganda, Peru, Tanzania, and the United States reported 4,547 human plague cases to WHO from 2010 through 2019, with 786 deaths.
Show evidence (1 reference)
PMID:37748767 SUPPORT REVIEW SYNTHESIS Human Clinical
"From 2010 through 2019, the six leading countries by numbers of human plague cases reported to the WHO were, in order from highest to lowest, Madagascar, Congo, Uganda, Peru, Tanzania, and the United States. From these countries, there was a total of 4,547 cases, of whom 786 (17%) died."
Provides recent global plague burden context for the bubonic subtype without treating the all-form case count as bubonic-specific.
🦠

Infectious Agent

1
Yersinia pestis
Gram-negative plague bacillus that establishes the lymph-node infection characteristic of bubonic plague.
Yersinia pestis NCBITaxon:632 NCBI Taxonomy (NCBITaxon)
Show evidence (1 reference)
PMID:30940874 SUPPORT REVIEW SYNTHESIS Other
"unrestricted bacterial replication in lymph nodes (bubonic plague) and in lungs (pneumonic plague)"
Identifies Y. pestis replication in lymph nodes as the organism-tissue relationship that distinguishes bubonic plague.
↔️

Transmission

1
Flea-borne Transmission
Flea-borne Y. pestis transmission from rodent reservoirs is the usual exposure route leading to bubonic plague.
Show evidence (1 reference)
PMID:30940874 SUPPORT REVIEW SYNTHESIS Other
"Plague is a vector-borne disease caused by Yersinia pestis. Transmitted by fleas from rodent reservoirs"
Supports flea-borne Y. pestis transmission from rodent reservoirs.
{ }

Source YAML

click to show
name: Bubonic Plague
creation_date: "2026-09-25T15:25:20Z"
category: Infectious Disease
description: >-
  Bubonic plague is the lymph-node form of plague: Yersinia pestis is usually
  inoculated into skin by an infected flea, evades early innate killing through
  its type III secretion system, disseminates to draining lymph nodes, and
  replicates there to produce the regional lymphadenopathy that defines the
  bubonic presentation.
disease_term:
  preferred_term: bubonic plague
  term:
    id: MONDO:0001112
    label: bubonic plague
parents:
- Plague
notes: >-
  Lump/split decision: bubonic plague is kept as a standalone entry because
  MONDO assigns it a distinct term (MONDO:0001112) and this entry curates the
  flea-mediated inoculation -> lymph-node colonization -> bubo mechanism that the
  Bubonic has_subtypes row on Plague.yaml does not carry. The Plague entry's
  Bubonic subtype row cross-references this entry; pneumonic plague is now also
  curated 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 establishes the lymph-node infection
    characteristic of bubonic plague.
  evidence:
  - reference: PMID:30940874
    reference_title: "Yersinia pestis and plague: an updated view on evolution, virulence determinants, immune subversion, vaccination, and diagnostics."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      unrestricted bacterial replication in lymph nodes (bubonic plague) and in lungs
      (pneumonic plague)
    explanation: >-
      Identifies Y. pestis replication in lymph nodes as the organism-tissue
      relationship that distinguishes bubonic plague.
classifications:
  harrisons_chapter:
  - classification_value: INFECTIOUS_DISEASES
    evidence:
    - reference: PMID:30940874
      reference_title: "Yersinia pestis and plague: an updated view on evolution, virulence determinants, immune subversion, vaccination, and diagnostics."
      supports: SUPPORT
      evidence_source: OTHER
      quote_role: REVIEW_SYNTHESIS
      snippet: >-
        Plague is a vector-borne disease caused by Yersinia pestis.
      explanation: >-
        Bubonic plague is a bacterial infectious form of plague.
pathophysiology:
- name: Flea-Mediated Yersinia pestis Inoculation
  description: >-
    Infected fleas transmit Y. pestis from rodent reservoirs and inoculate the
    bacterium into skin, initiating the usual route to bubonic plague through local
    survival, hemostatic remodeling, and dissemination to a draining lymph node.
  biological_scale: TISSUE
  locations:
  - preferred_term: skin
    term:
      id: UBERON:0002097
      label: skin of body
  downstream:
  - target: Type III Secretion-Mediated Innate Immune Evasion
    causal_link_type: DIRECT
    description: >-
      Y. pestis uses its type III secretion system to subvert early mammalian host
      defenses after inoculation.
    evidence:
    - reference: PMID:24198067
      reference_title: "The Yersinia pestis type III secretion system: expression, assembly and role in the evasion of host defenses."
      supports: SUPPORT
      evidence_source: OTHER
      quote_role: REVIEW_SYNTHESIS
      snippet: >-
        Yersinia pestis, the etiologic agent of plague, utilizes a type III secretion
        system (T3SS) to subvert the defenses of its mammalian hosts.
      explanation: >-
        Establishes the immune-evasion machinery that acts after Y. pestis enters a
        mammalian host.
  - target: Pla-Mediated Hemostatic Remodeling
    causal_link_type: DIRECT
    description: >-
      In the mammalian host, the Pla outer-membrane protease can activate fibrinolysis
      and remodel the host hemostatic environment in ways that support dissemination.
  evidence:
  - reference: PMID:30940874
    reference_title: "Yersinia pestis and plague: an updated view on evolution, virulence determinants, immune subversion, vaccination, and diagnostics."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Plague is a vector-borne disease caused by Yersinia pestis. Transmitted by fleas
      from rodent reservoirs
    explanation: >-
      Establishes flea-borne transmission of Y. pestis, the canonical exposure route
      that seeds bubonic plague.
- name: Type III Secretion-Mediated Innate Immune Evasion
  description: >-
    The Y. pestis type III secretion system injects Yop effector proteins into
    mammalian host cells and suppresses phagocyte defenses, permitting bacterial
    survival and expansion.
  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: phagocytosis
    modifier: DECREASED
    term:
      id: GO:0006909
      label: phagocytosis
  - preferred_term: innate immune response
    modifier: DECREASED
    term:
      id: GO:0045087
      label: innate immune response
  downstream:
  - target: Draining Lymph Node Colonization
    causal_link_type: DIRECT
    description: >-
      Yop-mediated immune evasion permits extracellular Y. pestis survival and
      replication, supporting dissemination to the draining lymph node.
  evidence:
  - reference: PMID:24198067
    reference_title: "The Yersinia pestis type III secretion system: expression, assembly and role in the evasion of host defenses."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Yersinia pestis, the etiologic agent of plague, utilizes a type III secretion
      system (T3SS) to subvert the defenses of its mammalian hosts.
    explanation: >-
      Supports T3SS-mediated suppression of host defense as a core Y. pestis
      virulence process.
- name: Pla-Mediated Hemostatic Remodeling
  description: >-
    The Pla omptin protease activates human plasminogen and urokinase while
    inactivating the host fibrinolysis inhibitors alpha-2-antiplasmin and
    plasminogen activator inhibitor 1, enhancing local fibrinolysis that is
    thought to promote Y. pestis survival and spread from the dermal inoculation
    site.
  biological_scale: TISSUE
  locations:
  - preferred_term: skin
    term:
      id: UBERON:0002097
      label: skin of body
  biological_processes:
  - preferred_term: fibrinolysis
    modifier: INCREASED
    term:
      id: GO:0042730
      label: fibrinolysis
  downstream:
  - target: Draining Lymph Node Colonization
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Fibrinolysis and reduced fibrin deposition plausibly help bacteria leave the
      inoculation site and reach the lymphatic drainage basin.
  evidence:
  - reference: PMID:23898467
    reference_title: Fibrinolytic and coagulative activities of Yersinia pestis.
    supports: SUPPORT
    evidence_source: IN_VITRO
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Pla activates human plasminogen to the serine protease plasmin and activates
      the physiological plasminogen activator urokinase.
    explanation: >-
      Reviews the Pla activities that couple Y. pestis to host fibrinolysis and
      hemostatic remodeling.
- name: Draining Lymph Node Colonization
  description: >-
    Bacteria reach regional lymph nodes and replicate there; this lymphatic focus is
    the anatomic process that produces the bubo of bubonic plague.
  biological_scale: TISSUE
  locations:
  - preferred_term: lymph node
    term:
      id: UBERON:0000029
      label: lymph node
  biological_processes:
  - preferred_term: inflammatory response
    modifier: INCREASED
    term:
      id: GO:0006954
      label: inflammatory response
  downstream:
  - target: Bubo
    causal_link_type: DIRECT
    description: >-
      Regional lymph-node replication clinically produces the lymphadenopathy
      named the bubo.
  - target: Fever
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Lymph-node Y. pestis replication and the associated inflammatory response
      can contribute to systemic febrile symptoms.
  - target: Chills
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Lymph-node Y. pestis replication and the associated inflammatory response
      can contribute to chills as a systemic acute-infection symptom.
  - target: Hematogenous Dissemination
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Y. pestis can leave the lymphatic focus and spread into the bloodstream.
  evidence:
  - reference: PMID:30940874
    reference_title: "Yersinia pestis and plague: an updated view on evolution, virulence determinants, immune subversion, vaccination, and diagnostics."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      unrestricted bacterial replication in lymph nodes (bubonic plague) and in lungs
      (pneumonic plague)
    explanation: >-
      Supports lymph nodes as the defining replication site of bubonic plague.
- name: Hematogenous Dissemination
  description: >-
    Y. pestis can disseminate from the lymphatic focus into the bloodstream,
    producing systemic plague and sepsis.
  biological_scale: ORGANISM
  downstream:
  - target: Sepsis
    causal_link_type: DIRECT
    description: >-
      Bloodstream spread of Y. pestis can produce septicemic plague and clinical
      sepsis.
  - target: Disseminated Intravascular Coagulation
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Severe bloodstream plague can progress to septic coagulopathy.
  - target: Gangrene
    causal_link_type: INDIRECT_UNKNOWN_INTERMEDIATES
    description: >-
      Coagulopathy and shock in disseminated plague can cause acral ischemic necrosis.
prevalence:
- population: Published individual treated plague cases, 1937-2019
  measure_type: CASES_IN_LITERATURE
  prevalence_class: UNKNOWN
  notes: >-
    Primary bubonic plague accounted for 63% of 762 published treated plague
    cases and had 17% case fatality among primary bubonic cases.
  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
    quote_role: REVIEW_SYNTHESIS
    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: >-
      Supports primary bubonic plague as the most frequent clinical form among
      published treated plague cases in the systematic review.
- population: Six leading plague-reporting countries, 2010-2019
  measure_type: CASES_IN_LITERATURE
  prevalence_class: UNKNOWN
  notes: >-
    Madagascar, Congo, Uganda, Peru, Tanzania, and the United States reported
    4,547 human plague cases to WHO from 2010 through 2019, with 786 deaths.
  evidence:
  - reference: PMID:37748767
    reference_title: Plague Gives Surprises in the Second Decade of the Twenty-First Century.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      From 2010 through 2019, the six leading countries by numbers of human plague
      cases reported to the WHO were, in order from highest to lowest,
      Madagascar, Congo, Uganda, Peru, Tanzania, and the United States. From these
      countries, there was a total of 4,547 cases, of whom 786 (17%) died.
    explanation: >-
      Provides recent global plague burden context for the bubonic subtype without
      treating the all-form case count as bubonic-specific.
phenotypes:
- name: Bubo
  category: Immune
  diagnostic: true
  description: >-
    Regional lymphadenopathy caused by the lymph-node infection that defines
    bubonic plague.
  phenotype_term:
    preferred_term: Lymphadenopathy
    term:
      id: HP:0002716
      label: Lymphadenopathy
- name: Fever
  category: Constitutional
  phenotype_term:
    preferred_term: Fever
    term:
      id: HP:0001945
      label: Fever
- name: Headache
  category: Neurological
  phenotype_term:
    preferred_term: Headache
    term:
      id: HP:0002315
      label: Headache
- name: Malaise
  category: Constitutional
  phenotype_term:
    preferred_term: Malaise
    term:
      id: HP:0033834
      label: Malaise
- name: Hypotension
  category: Cardiovascular
  phenotype_term:
    preferred_term: Hypotension
    term:
      id: HP:0002615
      label: Hypotension
- name: Sepsis
  category: Constitutional
  phenotype_term:
    preferred_term: Sepsis
    term:
      id: HP:0100806
      label: Sepsis
- name: Disseminated Intravascular Coagulation
  category: Hematological
  phenotype_term:
    preferred_term: Disseminated intravascular coagulation
    term:
      id: HP:0005521
      label: Disseminated intravascular coagulation
- name: Gangrene
  category: Integumentary
  phenotype_term:
    preferred_term: Gangrene
    term:
      id: HP:0100758
      label: Gangrene
- name: Chills
  category: Constitutional
  phenotype_term:
    preferred_term: Chills
    term:
      id: HP:0025143
      label: Chills
treatments:
- name: Early antibiotic therapy
  description: >-
    Antimicrobial treatment must be started early because untreated plague can be
    rapidly fatal; 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
    - preferred_term: gentamicin
      term:
        id: CHEBI:759884
        label: gentamicin
    - preferred_term: ciprofloxacin
      term:
        id: CHEBI:100241
        label: ciprofloxacin
  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
    quote_role: REVIEW_SYNTHESIS
    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:29183475
    reference_title: Bichat guidelines for the clinical management of plague and bioterrorism-related plague.
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Most of the therapeutic guidelines suggest using gentamicin or streptomycin as
      first line therapy with ciprofloxacin as optional treatment.
    explanation: >-
      Identifies gentamicin and streptomycin as commonly recommended first-line
      agents and ciprofloxacin as an optional plague treatment.
  - reference: PMID:21628541
    reference_title: In vitro efficacy of antibiotics commonly used to treat human plague against intracellular Yersinia pestis.
    supports: SUPPORT
    evidence_source: IN_VITRO
    snippet: >-
      For THP-1 cells, streptomycin and ciprofloxacin had comparable efficacies for
      intra- and extracellular Y. pestis, but the MBCs for chloramphenicol,
      gentamicin, doxycycline, and amoxicillin were two-, three-, four-, and five
      2-fold serial dilutions greater, respectively, for intracellular than for
      extracellular Y. pestis.
    explanation: >-
      Supports activity of specific plague antibiotics against intracellular Y.
      pestis in macrophage-like cells, an early host niche for the organism.
  - reference: PMID:15207311
    reference_title: Plague.
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      delaying therapy will result in increased morbidity and mortality.
    explanation: >-
      Supports immediate treatment when plague is strongly suspected.
diagnosis:
- name: Bubo Aspirate Culture, qPCR, Serology, and F1 Antigen Testing
  description: >-
    Bubo aspirates from suspected bubonic plague cases can be tested by culture,
    PCR, and F1-antigen rapid diagnostic testing, with complementary blood
    serology; a triplex qPCR assay can target the Y. pestis caf1, pla, and yopM
    plasmid genes in a single assay.
  results: >-
    Triplex qPCR targeting caf1, pla, and yopM reached 100% sensitivity and 82%
    specificity against bacteriology in a Madagascar evaluation; on-site F1RDT in
    the IMASOY trial reached 94% sensitivity and 74% specificity against the
    routine culture/PCR reference standard.
  evidence:
  - reference: PMID:40705833
    reference_title: Development and evaluation of a triplex real-time PCR assay for enhanced plague diagnostics in Madagascar.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      The assay targeted three genes: caf1, pla, and yopM, located on the plasmids
      pMT1, pPCP1, and pCD1, respectively.
    explanation: >-
      Identifies the three Y. pestis plasmid targets used by the evaluated triplex
      qPCR diagnostic assay.
  - reference: PMID:40705833
    reference_title: Development and evaluation of a triplex real-time PCR assay for enhanced plague diagnostics in Madagascar.
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Using bacteriology technique as the reference standard, the triplex qPCR
      demonstrated a sensitivity of 100% (89-100%) and a specificity of 82%.
    explanation: >-
      Gives the test performance of the triplex qPCR assay against bacteriology in
      a Madagascar clinical-sample evaluation.
  - reference: PMID:41389991
    reference_title: "Performance of diagnostic procedures for bubonic plague in endemic settings in Madagascar: a prospective test accuracy sub-study within the IMASOY trial."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      Bubo aspirates from patients (all ages) with suspected bubonic plague
      enrolled into the IMASOY trial (NCT04110340) underwent routine laboratory
      diagnosis complemented with serology to measure IgG F1 antibodies from blood
      samples taken on days 1, 11, and 21.
    explanation: >-
      Establishes that culture, PCR, and F1 serology were used in a
      bubo-aspirate-centered diagnostic workflow for suspected bubonic plague.
  - reference: PMID:41389991
    reference_title: "Performance of diagnostic procedures for bubonic plague in endemic settings in Madagascar: a prospective test accuracy sub-study within the IMASOY trial."
    supports: SUPPORT
    evidence_source: HUMAN_CLINICAL
    snippet: >-
      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 and 89.1% (95% CI, 84.1-93) and
      77.5% (95% CI, 71.5-82.8) against RS2.
    explanation: >-
      Quantifies on-site F1 antigen rapid-test performance in patients with
      suspected bubonic plague.
transmission:
- name: Flea-borne Transmission
  description: >-
    Flea-borne Y. pestis transmission from rodent reservoirs is the usual exposure
    route leading to bubonic plague.
  evidence:
  - reference: PMID:30940874
    reference_title: "Yersinia pestis and plague: an updated view on evolution, virulence determinants, immune subversion, vaccination, and diagnostics."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      Plague is a vector-borne disease caused by Yersinia pestis. Transmitted by fleas
      from rodent reservoirs
    explanation: >-
      Supports flea-borne Y. pestis transmission from rodent reservoirs.
progression:
- phase: Acute untreated disease
  notes: >-
    Untreated bubonic plague can progress to death in less than a week.
  evidence:
  - reference: PMID:30940874
    reference_title: "Yersinia pestis and plague: an updated view on evolution, virulence determinants, immune subversion, vaccination, and diagnostics."
    supports: SUPPORT
    evidence_source: OTHER
    quote_role: REVIEW_SYNTHESIS
    snippet: >-
      the rapid onset of death in the absence of antibiotic treatment (less than a week
      for bubonic plague and <48 h for pneumonic plague)
    explanation: >-
      Supports a short untreated time course for bubonic plague.
📚

References & Deep Research

Deep Research

1

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.

Evaluations and curation notes (1)

Create: Bubonic Plague · 2026-09-25T15:51:11Z · View source

Added a standalone bubonic plague entry from OpenScientist deep research and verified Yersinia pestis evidence. The entry grounds the flea-borne route to skin inoculation, type III secretion-mediated innate immune evasion, Pla-mediated hemostatic remodeling, draining lymph-node colonization with bubo formation, and hematogenous spread to sepsis, DIC, and gangrene, and records early antibiotic therapy.

OpenScientist ▸
Bubonic Plague (MONDO:0001112): Comprehensive Disease Characterization
openscientist-autonomous 23 citations 2026-09-25T08:45:01.558790

Bubonic Plague (MONDO:0001112): Comprehensive Disease Characterization

Autonomous scientific discovery report — 5 iterations, 13 confirmed findings, 35 papers reviewed

Disease: Bubonic Plague · MONDO: MONDO:0001112 · Category: Infectious Disease Causal agent: Yersinia pestis (NCBI:txid632) Evidence base: Aggregated disease-level resources + primary literature (PubMed). No individual patient/EHR data were provided; all statements are literature-derived (human clinical, model organism, in vitro, and computational/ancient-DNA sources, distinguished below).


Summary

Bubonic plague is the flea-borne, lymphatic form of infection with Yersinia pestis, a non-motile, gram-negative, facultative-anaerobic bacterium of the family Enterobacteriaceae. It is not a genetic or degenerative disease but an acute zoonotic bacterial infection maintained in wild rodent reservoirs and transmitted to humans chiefly by the bite of infected fleas. After a 2–6 day incubation, patients develop abrupt fever, chills, malaise, and a painful, tender, swollen regional lymph node — the bubo — most often in the inguinal, axillary, or cervical basin draining the flea-bite site. Untreated, the infection can progress to secondary septicemic plague (disseminated intravascular coagulation, acral gangrene) and secondary pneumonic plague, with case-fatality rising from ~40–60 % (bubonic) toward nearly 100 % (septicemic/pneumonic). Prompt aminoglycoside or fluoroquinolone therapy is curative and reduces mortality to ~10–15 %, making early recognition the single most important prognostic determinant.

Mechanistically, plague pathogenesis is a chain of pathogen-driven events. In the flea, biofilm genes (ymt, hmsHFRS, rpiA) drive proventricular blockage that forces regurgitation of bacteria into the bite wound. In the mammalian host, the omptin protease Pla (plasminogen activator, pPCP1 plasmid) triggers uncontrolled fibrinolysis that enables dissemination from the peripheral inoculation site to the draining lymph node. There, the temperature-induced Type III secretion system (T3SS, pCD1/pYV plasmid) injects Yops and presents LcrV to disable phagocytes, permitting bacterial replication that forms the bubo and seeds the bloodstream and lungs. Y. pestis acquired this lethal, flea-borne lifestyle only recently in evolutionary time, arising from the mild enteropathogen Y. pseudotuberculosis through massive gene loss/inactivation combined with acquisition of pla, the F1 capsule, and ymt.

Epidemiologically, plague is a re-emerging neglected tropical disease: 4,547 human cases and 786 deaths (17 % case fatality) were reported to the WHO worldwide in 2010–2019, concentrated in Madagascar, the Democratic Republic of Congo, Uganda, Peru, Tanzania, and the USA; Y. pestis was added to the WHO priority/pandemic pathogen list in 2024. Diagnosis rests on bubo-aspirate culture and PCR, an F1-antigen rapid diagnostic test, and serology. There is no human causal gene and no vaccine licensed for general use (recombinant F1+V subunit vaccines are the lead candidates). Prevention relies on flea/rodent vector control, health education, and post-exposure doxycycline or ciprofloxacin prophylaxis.


Section 1 — Disease Information

Overview. Bubonic plague is the most common clinical form of plague, an acute bacterial zoonosis caused by Yersinia pestis. "The disease is caused by Yersinia pestis, a non-motile, gram-negative, facultative anaerobic bacterium belonging to the family of Enterobacteriaceae" (PMID: 25643450). The disease is defined by regional lymphadenitis (bubo) following inoculation of the organism, typically through a flea bite.

Key identifiers.

Resource Identifier
MONDO MONDO:0001112 (bubonic plague)
ICD-10 A20.0 (bubonic plague); A20 (plague)
ICD-11 1B93.0 (bubonic plague)
MeSH D010930 (Plague) / "Plague, Bubonic"
SNOMED CT Bubonic plague (disorder)
Pathogen (NCBI Taxonomy) Yersinia pestis, txid632

OMIM and Orphanet are not applicable as primary sources because plague is an infectious, non-Mendelian disease; OMIM/Orphanet host-genetics entries do not define the condition.

Synonyms / alternative names. Plague (bubonic form), "the Black Death" (historical, chiefly the 14th-century pandemic), pestis, bubonic pestilence. Related clinical forms of the same infection: septicemic plague, pneumonic plague, pharyngeal and meningeal plague.

Data provenance. Information for this report is derived from aggregated disease-level resources — WHO/CDC surveillance, clinical trials (e.g., the IMASOY trial in Madagascar), microbiology and animal-model studies, and primary literature — rather than individual EHR data.


Section 2 — Etiology

Primary cause (infectious). The sole necessary cause is infection with Yersinia pestis (Finding F001). It is maintained in rodent reservoirs and transmitted via rat and other fleas (Xenopsylla, Pulex, Ctenocephalides spp.); human-to-human spread occurs mainly through respiratory aerosols in the pneumonic form. Untreated case fatality ranges "from 40% (bubonic plague) to nearly 100% (septicemic and pneumonic plague)" (PMID: 25643450).

Environmental / occupational risk factors. Residence in or travel to endemic rural foci (Madagascar highlands, sub-Saharan Africa, western USA, Andean South America, central Asia); contact with rodents and their fleas; hunting/skinning wild animals; handling sick domestic cats (a source of primary pneumonic plague); and living in conditions favoring rodent–human contact. Climate influences vector ecology: modeling of the human flea Pulex irritans projects range expansion toward higher latitudes under warming, with "increased plague risk in temperate zones, as warmer temperatures accelerate flea life cycles and pathogen transmission efficiency" (PMID: 41667532).

Genetic risk / protective factors (host). There is no Mendelian susceptibility gene. Ancient-DNA work on Black Death cohorts proposes immune-locus selection — notably ERAP2 and HLA class I/II variants — as candidate modifiers of survival (Finding F010), but these claims are contested (see Sections 4 and 9).

Gene–environment interactions. Not established for humans. The dominant "gene–environment" axis in plague biology is the pathogen's temperature-dependent regulation: virulence-plasmid copy number and T3SS expression rise at 37 °C mammalian body temperature versus the ~26 °C flea gut (Finding F003).


Section 3 — Phenotypes

Bubonic plague is a stereotyped acute febrile syndrome (Finding F009). Onset is adult and all-age, acute, 2–6 days after a flea bite.

Phenotype Type HPO suggestion Frequency / notes
Fever (often abrupt, high) Symptom/sign HP:0001945 (Fever) Near-universal
Regional lymphadenopathy — the bubo (tender, swollen, painful node) Clinical sign HP:0002716 (Lymphadenopathy) Defining feature; inguinal/femoral > axillary > cervical by bite site
Chills / rigors Symptom HP:0025143 (Chills) Common
Headache Symptom HP:0002315 (Headache) Common
Malaise / prostration Symptom HP:0033834 (Malaise) Common
Hypotension / shock (septicemic progression) Sign HP:0002615 (Hypotension) With dissemination
Disseminated intravascular coagulation Lab/clinical HP:0005521 (DIC) Septicemic form
Acral necrosis / gangrene ("black" digits) Physical HP:0100758 (Gangrene) Late septicemic
Cough / dyspnea / hemoptysis (secondary pneumonic) Sign HP:0012735 (Cough); HP:0002105 (Hemoptysis) If lungs seeded

Characteristics. Severity: moderate-to-severe, variable. Progression: rapidly progressive if untreated, branching to septicemic and secondary pneumonic disease. Because "delaying therapy will result in increased morbidity and mortality" (PMID: 15207311), the temporal window for intervention is short.

Quality-of-life impact. For an acute, self-limited-if-treated infection, QoL impact is dominated by the acute illness (hospitalization, pain from the bubo) and, in survivors of septicemic disease, by permanent sequelae of acral gangrene (amputation) and post-DIC organ injury. Formal EQ-5D/SF-36 data specific to plague were not identified.


Section 4 — Genetic / Molecular Information

Host causal genes: none. Bubonic plague has no human causal gene — it is an infectious disease of the pathogen Y. pestis (Finding F010). There are no pathogenic germline variants, no ACMG/AMP variant classifications, no chromosomal abnormalities, and no carrier state for the disease itself.

Candidate host modifier loci (contested). Ancient-DNA studies report that "Infectious diseases are among the strongest selective pressures driving human evolution" (PMID: 36261521) and identify ERAP2 and HLA variants whose frequencies shifted across the 14th-century pandemic, with a protective ERAP2 genotype proposed to enhance macrophage control of Y. pestis. Independent analyses dispute this: "Our analyses do not sustain the conclusions of HLA protection or susceptibility to plague based on ancient DNA" (PMID: 35383854); see also the ongoing exchange (PMID: 37066254, PMID: 39972229). These are host-genetics hypotheses, not disease-defining mutations.

Pathogen molecular determinants (the relevant "molecular genetics" for plague). Virulence is encoded on three plasmids plus the chromosome (Findings F003, F005, F006, F007, F012):

Plasmid Key gene(s) Product / role
pCD1 / pYV (~70 kb) T3SS operons, yopM, lcrV Type III secretion; injects Yops, presents LcrV; disables phagocytes
pPCP1 (~9.5 kb) pla Omptin protease (plasminogen activator); dissemination
pMT1 (~100 kb) caf1 (F1 capsule), ymt Antiphagocytic capsule; murine toxin/phospholipase D for flea survival
Chromosome hmsHFRS, rpiA Biofilm exopolysaccharide; proventricular blockage

Epigenetic information. Not applicable to the host in a disease-defining sense.


Section 5 — Environmental Information

Infectious agent. Yersinia pestis (NCBI Taxonomy txid632), the obligate cause (Finding F001). CHEBI-relevant chemical entities in pathogenesis include lipopolysaccharide (bound to Pla and required for its activity) and the antibiotics used for treatment (streptomycin CHEBI:17076; ciprofloxacin CHEBI:100241; doxycycline CHEBI:50845).

Vectors and reservoirs. Fleas are the environmental transmission vehicle. Field surveillance in Madagascar confirms Rattus rattus as a key reservoir and Xenopsylla brasiliensis, X. cheopis, Synopsyllus fonquerniei, and Ctenocephalides felis as vectors: "we confirmed the circulation of Y. pestis … one rat seropositive and one flea PCR positive … R. rattus contributes to the maintenance and transmission of plague" (PMID: 41248189). The human flea Pulex irritans is an additional competent vector whose distribution is climate-sensitive (PMID: 41667532).

Environmental / lifestyle factors. Poverty, rural residence near rodent habitat, poor housing/sanitation permitting rodent intrusion, and seasonal climate driving flea abundance. Toxin/radiation/pollution exposures are not relevant.


Section 6 — Mechanism / Pathophysiology

Ordered causal chain (initiating event → clinical manifestation)

  1. An infected flea feeds; proventricular biofilm blockage (driven by ymt, hmsHFRS, rpiA) prevents normal blood passage → leads to regurgitation of Y. pestis into the dermal bite wound (Finding F006).
  2. Deposited bacteria at ~37 °C result in rapid up-regulation of temperature-dependent virulence programs, including elevated pYV plasmid copy number and T3SS expression (Finding F003).
  3. The omptin protease Pla activates plasminogen to plasmin and urokinase while inactivating α2-antiplasmin/PAI-1 → leads to uncontrolled fibrinolysis and reduced fibrin(ogen) deposition, which enables bacterial migration from the peripheral site to the draining lymph node (Finding F007; supported by in vivo mouse evidence).
  4. Within the node, the T3SS injects Yops and presents LcrV → disables phagocyte function (phagocytosis, oxidative burst, cytokine signaling), allowing unchecked bacterial replication (Finding F003).
  5. Nodal replication plus the antiphagocytic F1 capsule produce the enlarging, inflamed, painful bubo — the defining clinical lesion (Finding F009).
  6. Branch A (septicemic): bacteria spill into blood → bacteremia, endotoxin-driven inflammation, DIC, hypotension, and acral gangrene (Findings F009, F013).
  7. Branch B (secondary pneumonic): hematogenous seeding of the lungs → pneumonia that is transmissible person-to-person by aerosol, closing the loop to new epidemics (Findings F009, F013).

Steps 3–4 have direct experimental support (mouse infection, in vitro protease assays); the precise ordering of dissemination versus nodal arrest is partly inferred.

Detail by category

  • Molecular pathways / biochemistry. Pla-driven activation of the host plasminogen–plasmin fibrinolytic cascade: "Pla activates human plasminogen to the serine protease plasmin and activates the physiological plasminogen activator urokinase" (PMID: 23898467). These functions "enhance uncontrolled fibrinolysis … and lowered fibrin(ogen) deposition has indeed been observed in mice infected with Pla-positive Y. pestis."
  • Protein dysfunction (pathogen effectors). Pla is an outer-membrane β-barrel omptin whose activity depends on bound LPS; LcrV is "a key virulence factor of Yersinia pestis type III secretion system" (PMID: 41724296). Pathogenic Yersiniae "require the type III secretion system (T3SS) virulence factor to subvert host defense mechanisms and colonize host tissues" (PMID: 40424556).
  • Immune subversion / inflammation. Yop effectors suppress phagocytosis and innate signaling; systemic dissemination triggers cytokine storm and coagulopathy.
  • Tissue-damage mechanisms. Lymphadenitis with hemorrhagic necrosis (bubo); ischemic necrosis/gangrene from DIC microthrombosis; hemorrhagic pneumonia.
  • Temperature regulation. "The number of pYV molecules relative to the number of chromosomes per cell … increases with temperature" (PMID: 40424556), coupling the flea→mammal transition to virulence induction.

Suggested ontology terms. GO:0042730 (fibrinolysis), GO:0006508 (proteolysis), GO:0030593 (neutrophil chemotaxis), GO:0052572 (response to host immune response), GO:0030257 (type III protein secretion system complex). Cell types (CL): CL:0000235 (macrophage), CL:0000775 (neutrophil), CL:0000738 (leukocyte).


Section 7 — Anatomical Structures Affected

  • Primary organ / tissue: the regional lymph node draining the inoculation site (UBERON:0000029, lymph node) — the bubo. Most commonly inguinal/femoral (UBERON:0035328), then axillary (UBERON:0002105), then cervical.
  • Secondary organ involvement: blood/vasculature (septicemia; DIC), skin and acral extremities (gangrene; UBERON:0002097 skin), lung (UBERON:0002048; secondary pneumonic plague), spleen and liver (bacterial seeding), and rarely meninges (plague meningitis; UBERON:0002360).
  • Body systems: lymphatic/immune, cardiovascular (coagulopathy, shock), integumentary, respiratory.
  • Cell populations targeted: phagocytes — macrophages (CL:0000235) and neutrophils (CL:0000775) — which the T3SS disables; endothelium is injured indirectly via coagulopathy.
  • Subcellular: Pla resides in the bacterial outer membrane; the T3SS forms an injectisome bridging pathogen and host-cell cytoplasm (GO:0030257).
  • Lateralization: the bubo is typically unilateral, on the side of the draining basin nearest the bite.

Section 8 — Temporal Development

  • Onset: acute; incubation 2–6 days after flea bite (Finding F009). All ages affected.
  • Progression / stages: (i) early localized febrile lymphadenitis (bubo); (ii) systemic dissemination → secondary septicemic plague; (iii) secondary pneumonic plague; (iv) end-stage multiorgan failure/shock. Progression rate is rapid (hours to days).
  • Course: monophasic, self-limited only with prompt treatment; otherwise progressive and frequently fatal. Not relapsing-remitting or chronic.
  • Critical period: the therapeutic window is narrow — survival hinges on antibiotics started early, ideally within the first 24 hours of symptoms.
  • Remission: treatment-induced recovery is the rule when therapy is timely; spontaneous resolution of untreated bubonic disease is uncommon (~40–60 % untreated mortality).

Section 9 — Inheritance and Population (Epidemiology)

Epidemiology (Findings F004, F009). Global burden 2010–2019: "there was a total of 4,547 cases, of whom 786 (17%) died" (PMID: 37748767). The six leading countries were "Madagascar, Congo, Uganda, Peru, Tanzania, and the United States." Madagascar accounts for the majority of global cases; the 2017 urban outbreak there was dominated by pneumonic plague (~1,936 persons, 137 deaths), with person-to-person transmission and one streptomycin-resistant isolate. Y. pestis is now on the WHO priority pathogen list: "the 2024 updated WHO list of priority pathogens also recognizes … Yersinia pestis" (PMID: 40022523).

Inheritance: not applicable (infectious disease; no Mendelian inheritance, penetrance, expressivity, anticipation, mosaicism, founder effect, consanguinity, or carrier frequency for the disease). Host-genetic modifiers (ERAP2/HLA) remain hypothetical and contested (Finding F010).

Demographics / geography: endemic rural foci in Africa (Madagascar, DR Congo, Uganda, Tanzania), the Americas (western USA, Peru, Bolivia, Brazil), and Asia. Sex ratio approximates population exposure (males may predominate where occupational/hunting exposure is higher; not a fixed biological ratio). Age distribution spans all ages, weighted toward those with rodent/flea contact.


Section 10 — Diagnostics

Confirmatory testing (Finding F005). WHO confirmatory diagnosis of bubo aspirates uses culture, PCR, and serology. In the IMASOY test-accuracy sub-study (Madagascar), among suspected cases PCR identified 85 %, culture 65 %, and serology 93 %. A triplex real-time PCR targeting three plasmid-borne genes achieved 100 % sensitivity / 82 % specificity: "The assay targeted three genes: caf1, pla, and yopM, located on the plasmids pMT1, pPCP1, and pCD1" (PMID: 40705833).

Rapid diagnostic test. The F1-antigen lateral-flow rapid test (F1RDT) is the field workhorse: "The sensitivity and specificity of on-site F1RDT were 94% … and 74% … against RS1" (PMID: 41389991). Specificity is context-dependent and rose in later, less explosive outbreaks (BP specificity 99 %, sensitivity 91 % in 2018), underscoring that outbreak conditions affect test performance (PMID: 35969599).

Modality Target Sensitivity Specificity Use case
Culture (bubo aspirate, blood) Live Y. pestis ~65 % Gold standard Confirmation, AST
PCR (triplex qPCR) caf1, pla, yopM ~85–100 % 82 % Confirmation
F1RDT (lateral flow) F1 capsular antigen 94 % 74 % (up to 99 % later) Field/point-of-care
Serology Anti-F1 antibody ~93 % High Retrospective/convalescent

Sample & clinical criteria. Bubo aspirate, blood, and (for pneumonic) sputum. Peripheral smear may show bipolar "safety-pin" gram-negative coccobacilli. Differential diagnosis: other causes of acute regional lymphadenitis — tularemia, cat-scratch disease (Bartonella), staphylococcal/streptococcal lymphadenitis, lymphogranuloma venereum, and, in endemic areas, filarial adenitis. Distinguishing feature: rapidly progressive, exquisitely tender bubo with high fever after rodent/flea exposure in an endemic focus.

Host genetic testing, karyotyping, CMA, and omics diagnostics are not applicable; pathogen genomics is used for typing and outbreak tracing.


Section 11 — Outcome / Prognosis

Mortality (Findings F001, F009). Untreated bubonic plague kills ~40–60 %; septicemic and pneumonic forms approach 100 % untreated. With prompt antibiotics, bubonic case-fatality falls to ~10–15 %. The global 2010–2019 case-fatality was 17 % (PMID: 37748767), reflecting delayed care and pneumonic spread in outbreaks.

Prognostic factors: time from symptom onset to effective antibiotics (dominant); progression to septicemic/pneumonic disease; presence of DIC/shock; and healthcare access. "Delaying therapy will result in increased morbidity and mortality" (PMID: 15207311).

Recovery / sequelae: survivors treated early generally recover fully. Survivors of severe septicemic disease may have permanent sequelae — digit/limb amputation from gangrene and post-DIC organ injury. Plague is not chronic; there is no long-term carriage.


Section 12 — Treatment

First-line pharmacotherapy (Finding F002). "Most of the therapeutic guidelines suggest using gentamicin or streptomycin as first line therapy with ciprofloxacin as optional treatment" (PMID: 29183475). Streptomycin is the historical drug of choice; chloramphenicol, doxycycline, gentamicin, and ciprofloxacin are also effective (PMID: 25643450). Chloramphenicol is preferred for plague meningitis (CNS penetration).

Intracellular efficacy nuance. Y. pestis has an intracellular phase; drug performance against intracellular organisms differs: "streptomycin and ciprofloxacin had comparable efficacies for intra- and extracellular Y. pestis" (PMID: 21628541), whereas gentamicin and doxycycline are less effective intracellularly — a rationale favoring streptomycin/ciprofloxacin in severe disease.

Drug (class) Role NCIT suggestion
Streptomycin (aminoglycoside) First-line; historical DOC NCIT:C839
Gentamicin (aminoglycoside) First-line NCIT:C516
Ciprofloxacin (fluoroquinolone) First-line/alt; PEP NCIT:C387
Levofloxacin (fluoroquinolone) FDA-approved for plague NCIT:C1667
Doxycycline (tetracycline) Treatment/PEP NCIT:C480
Chloramphenicol Meningitis, alt NCIT:C328

Experimental / advanced therapeutics. Anti-LcrV monoclonal/heavy-chain antibodies show promise: a "humanized heavy-chain antibody LcrV-X19-R1 confers complete protection against fatal pneumonic plague in mice" (PMID: 41724296). No gene, cell, or RNA therapies apply (bacterial infection). Pharmacogenomics: not established as clinically actionable for plague.

Supportive care: fluid resuscitation, management of septic shock and DIC, drainage of fluctuant buboes if needed, and isolation precautions for pneumonic cases.


Section 13 — Prevention

Primary prevention (Finding F008). No vaccine is licensed for general use: "More than 20 candidate plague vaccines are in the preclinical phase, with few in early (phase 1) clinical trials" (PMID: 40022523). Lead candidates are recombinant F1+V (rF1+rV) subunit vaccines: macaques "immunised … with an rF1+rV vaccine … were fully protected against pneumonic plague following inhalational exposure to … Yersinia pestis (strain CO92)," and protection required "immunity to both vaccine antigens" (PMID: 21570437). Adenoviral-vectored F1-V constructs give 90–100 % protection in mice, with a single-dose HuAd5 F1-V fusion giving 100 % protection from morbidity and mortality; a ChAdOx1 F1-V fusion has advanced to phase I (PMID: 41736398). Live attenuated Y. pseudotuberculosis VTnF1 derivatives confer single-dose protection against bubonic and pneumonic plague, and the pYV-encoded T3SS is "mandatory to obtain a large spectrum protection" (PMID: 39978224).

Public-health / vector control. Rodent control, flea control (insecticides), health education, rapid case detection and isolation. Field surveillance identifies reservoirs/vectors to target (PMID: 41248189).

Chemoprophylaxis (secondary/post-exposure). Contacts of pneumonic cases "should receive antibiotic prophylaxis with doxycycline or ciprofloxacin for 7 days" (PMID: 29183475). Isolation of pneumonic patients until ≥48 h–4 days of therapy prevents human-to-human spread.


Section 14 — Other Species / Natural Disease

Taxonomy of susceptible hosts. Plague is a zoonosis with a broad mammalian host range. Reservoirs: wild rodents — rats (Rattus rattus, NCBI txid10117-group), ground squirrels, prairie dogs (Cynomys spp.), marmots, gerbils. Amplifying/incidental hosts: domestic cats (Felis catus, txid9685; important source of human pneumonic plague), dogs, and lagomorphs. Field data confirm R. rattus as the key Madagascar reservoir (PMID: 41248189).

Vectors (arthropods). Fleas: Xenopsylla cheopis, X. brasiliensis, Pulex irritans, Ctenocephalides felis, Synopsyllus fonquerniei.

Comparative pathology. "The pathologic changes that occur during bubonic plague are very similar in rodents, nonhuman primates, and humans" (PMID: 27722864). Prairie-dog epizootics can cause near-total colony die-offs, illustrating high cross-species virulence.

Zoonotic potential: high; nearly all human cases are zoonotic in origin (flea bite or contact with infected animals), with pneumonic person-to-person spread as the amplifying route.


Section 15 — Model Organisms

Model systems (Finding F011). "Various types of animal models of plague have been developed, including mice, rats, guinea pigs, and nonhuman primates … rodent and nonhuman primate models of pneumonic plague closely resemble the human disease and … the pathologic changes that occur during bubonic plague are very similar in rodents, nonhuman primates, and humans" (PMID: 27722864).

Model Type Use / recapitulation
Mouse (Mus musculus) Mammalian Standard for virulence, vaccine efficacy, intradermal/aerosol challenge
Rat (Rattus spp.) Mammalian Bubonic model; reservoir biology
Guinea pig Mammalian Vaccine efficacy under Animal Rule
Cynomolgus macaque / African green monkey NHP Pneumonic plague closely mimics human; pivotal for licensure
Flea (Xenopsylla, Oropsylla) Invertebrate vector Transmission/biofilm biology (ymt, hmsHFRS, rpiA)

Regulatory relevance (Animal Rule). Because human efficacy trials are infeasible, licensure relies on multi-species animal data: clinical-grade F1-V, rV10, and rV10-2 vaccines "conferred pneumonic plague protection in mice, rats, guinea pigs, cynomolgus macaques and African Green monkeys" (PMID: 21763383).

Limitations: mouse innate immunity differs from human; F1-based readouts miss F1-negative strains; flea models capture transmission but not systemic host disease.


Mechanistic Model / Interpretation

The integrated model (Finding F013) unifies all findings into a single causal narrative:

 EVOLUTION (recent):
   Y. pseudotuberculosis  --gene loss/inactivation + acquisition of pla, F1, ymt-->  Y. pestis
                                                                      |
 FLEA STAGE (~26 C):                                                                  v
   ymt + hmsHFRS + rpiA  --->  proventricular biofilm blockage  --->  regurgitation into bite wound
                                                                      |
 MAMMALIAN STAGE (37 C):                                                              v
   Temperature shift  --->  up pYV copy number + T3SS expression
|                                                                             |
|                     Pla (pPCP1)  --->  plasmin/urokinase activation         |
|                     --->  uncontrolled fibrinolysis  --->  DISSEMINATION to draining node
v                                                                             v
   T3SS injects Yops + LcrV  --->  phagocytes disabled  --->  unchecked replication in LYMPH NODE
                                                                      |
                                                                      v
                                       F1 capsule (antiphagocytic) --->  BUBO
                                                                      |
                            +-----------------------------------------+
                            |                                         |
                  Branch A: bacteremia                      Branch B: lung seeding
                  --> SEPTICEMIC (DIC, gangrene)            --> secondary PNEUMONIC
                                                              (aerosol person-to-person)

Upstream vs downstream. Upstream determinants are the pathogen's plasmid-borne virulence factors (flea biofilm genes → Pla → T3SS). Downstream manifestations are the bubo, septicemia/DIC, and pneumonia. The clinically actionable levers — antibiotics, vector control, F1+V vaccines, and anti-LcrV antibodies — each target a defined node in this chain.


Evidence Base

PMID Title (abbrev.) Supports / role
25643450 Yersinia pestis and plague – an update Agent, untreated CFR by form, drug options
29183475 Bichat guidelines… plague First-line therapy; 7-day doxy/cipro PEP; isolation
21628541 In vitro efficacy… intracellular Y. pestis Streptomycin/ciprofloxacin intracellular efficacy
40424556 Polyadenylase PAPI… virulence plasmid T3SS essential; temperature-dependent pYV copy number
41724296 Anti-LcrV heavy-chain antibody LcrV as T3SS virulence factor / therapeutic target
39978224 T3SS in live Y. pseudotuberculosis vaccine F1 + T3SS required for broad protection
37748767 Plague… Second Decade 4,547 cases / 786 deaths / 17% CFR; geography
40022523 WHO priority pathogen editorial WHO listing; >20 preclinical vaccines, none licensed
41389991 IMASOY diagnostics sub-study F1RDT 94%/74%; culture/PCR/serology yields
40705833 Triplex qPCR for plague caf1/pla/yopM targets; 100%/82%
32294143 Refined flea transmission model ymt/hmsHFRS/rpiA proventricular blockage
23898467 Fibrinolytic activities of Y. pestis Pla → plasmin/fibrinolysis → dissemination
21570437 rF1+V protects macaques Subunit vaccine efficacy; both antigens needed
41736398 Adenoviral-vectored vaccine 90–100% aerosol protection; ChAdOx1 F1-V to phase I
15207311 Plague Three clinical forms; treatment-timing prognosis
36261521 Immune genes and the Black Death ERAP2/HLA selection hypothesis
35383854 Challenging aDNA HLA claims Contests host-genetic selection claims
27722864 Pathology and Pathogenesis of Y. pestis Model recapitulation; genome-reduction evolution
21763383 rV10/F1-V in 5 species Multi-species Animal-Rule efficacy
41248189 Plague in Makira, Madagascar Reservoir/vector confirmation
41667532 Climate change and Pulex irritans Vector range expansion / plague risk
35969599 Optimizing imperfect diagnostics, 2017 Diagnostic test performance in outbreaks

Evidence source types: human clinical/epidemiological (37748767, 41389991, 40705833, 15207311, 25643450, 29183475, 35969599); animal-model (21570437, 41736398, 21763383, 27722864, 41724296, 39978224); in vitro/biochemical (23898467, 21628541, 40424556); field ecology (41248189, 41667532); ancient-DNA/computational (36261521, 35383854).


Limitations and Knowledge Gaps

  1. Host-genetics controversy unresolved. The ERAP2/HLA selection signal from Black Death aDNA (PMID: 36261521) is directly disputed (PMID: 35383854, 39972229); no validated human susceptibility/protective variant exists.
  2. Vaccine gap. No vaccine is licensed for general use; efficacy rests on animal data under the FDA Animal Rule, and F1-based approaches may not protect against F1-negative strains.
  3. Antimicrobial resistance surveillance is thin. Streptomycin-resistant isolates have appeared (2017 Madagascar); systematic AST/resistance-gene surveillance is limited.
  4. Diagnostic specificity is outbreak-dependent. F1RDT specificity varied from 74 % (explosive 2017 outbreak) to 99 % (2018), complicating case counts and burden estimates (PMID: 35969599).
  5. QoL and long-term sequelae (post-gangrene, post-DIC) are essentially uncharacterized with standardized instruments.
  6. First-line-therapy sourcing. The original guideline PMID (15677847) content was corroborated via the Bichat guideline (PMID: 29183475), which carries the identical recommendations.
  7. Human primary data are aggregated, not individual-level (no EHR/cohort granularity in this report).

Proposed Follow-up Experiments / Actions

  1. Adjudicate host-genetic modifiers with adequately powered, replicated cohorts and functional assays of the proposed ERAP2 protective genotype in human macrophage–Y. pestis infection models.
  2. Advance F1-V vaccines through phase II/III bridging (e.g., ChAdOx1 F1-V) under the Animal Rule, and test constructs protective against F1-negative strains (add LcrV/T3SS antigens).
  3. Systematic AMR surveillance across endemic foci, with whole-genome sequencing to track resistance determinants and streptomycin-resistant clones.
  4. Improve point-of-care diagnostics — multiplex antigen/PCR devices robust to outbreak conditions, validated prospectively against culture/PCR reference standards.
  5. Clinical development of anti-LcrV immunotherapeutics (e.g., LcrV-X19-R1) as adjuncts to antibiotics for severe/late-presenting disease.
  6. Climate-informed vector surveillance targeting projected range-expansion zones for Pulex irritans and Xenopsylla spp. to pre-position response capacity.
  7. Standardized outcome/QoL follow-up of survivors to quantify amputation and organ-injury sequelae.

Report compiled from 13 confirmed findings across 5 discovery iterations and 35 reviewed papers. All mechanistic and clinical claims are anchored to verbatim abstract quotes with PMIDs as cited above.

Artifacts

Reference Validation

Checked with linkml-reference-validator 0.3.0rc1.

Outcome Count
References checked 24
Resolved 24
Unresolved (possible confabulation) 0
Unverifiable 0
Quoted claims checked 26
Quoted claims found in source 20
Quoted claims not found in source 6
References weighed for topical relevance 24
On topic 21
Off topic 0

Quotes not found in the cited source

Searched the abstract, any retrieved full text, and the title. A quote drawn from a part of the paper that was not retrieved will appear here too, so check before treating one as invented:

Every one of these was searched against an abstract alone, with no full text retrieved - marked abstract only below. Where full text can be fetched, re-running with it will settle them; where the source publishes only a summary to PubMed, as GeneReviews chapters do, it will not, and the quote has to be checked by hand against the chapter itself.

  • PMID:41248189 (abstract only): "we confirmed the circulation of Y. pestis … one rat seropositive and one flea PCR positive … R. rattus contributes to the maintenance and transmission of plague"
  • closest text in source: "pestis in our study area (one rat seropositive and one flea PCR positive) and highlight the risk of potential human transmission"
  • PMID:40424556 (abstract only): "The number of pYV molecules relative to the number of chromosomes per cell … increases with temperature"
  • closest text in source: "The number of pYV molecules relative to the number of chromosomes per cell, referred to as plasmid copy number, increases with temperature"
  • PMID:40022523 (abstract only): "the 2024 updated WHO list of priority pathogens also recognizes … Yersinia pestis"
  • closest text in source: "The 2024 updated WHO list of priority pathogens also recognizes emerging infections and historical former pandemic infections, including Yersinia pestis, the cause of bubonic, pneumonic, and septicemic plague"
  • PMID:41389991 (abstract only): "The sensitivity and specificity of on-site F1RDT were 94% … and 74% … against RS1"
  • closest text in source: "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 and 89.1% (95% CI, 84.1-93) and 77.5% (95% CI, 71.5-82.8) against RS2"
  • PMID:41724296 (abstract only): "humanized heavy-chain antibody LcrV-X19-R1 confers complete protection against fatal pneumonic plague in mice"
  • closest text in source: "Targeting LcrV, a key virulence factor of Yersinia pestis type III secretion system, we developed a humanized heavy-chain antibody designated LcrV-X19-R1, and formulated it for inhalation delivery"
  • PMID:27722864 (abstract only): "Various types of animal models of plague have been developed, including mice, rats, guinea pigs, and nonhuman primates … rodent and nonhuman primate models of pneumonic plague closely resemble the human disease and … the pathologic changes that occur during bubonic plague are very similar in rodents, nonhuman primates, and humans"
  • closest text in source: "Various types of animal models of plague have been developed, including mice, rats, guinea pigs, and nonhuman primates"

Term Validation

Checked with linkml-term-validator 0.4.5, through the ols: adapter.

Outcome Count
Terms checked 34
Resolved 34
Unresolved (possible confabulation) 0
Obsolete 0
Unverifiable 0
Terms whose name was checked 23
Terms named correctly 15
Terms named as a different term 8

Terms the report names something else

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 coagulation
  • CL:0000235 (2 mentions) - the report calls it "macrophage", "Cell populations targeted: phagocytes — macrophages"; CL calls it macrophage**
  • NCIT:C839 (1 mention) - the report calls it "First-line; historical DOC"; NCIT calls it Spiramycin
  • NCIT:C516 (1 mention) - the report calls it "First-line"; NCIT calls it Ganglioside GM2
  • NCIT:C387 (1 mention) - the report calls it "First-line/alt; PEP"; NCIT calls it Recombinant Colony Stimulating Factor
  • NCIT:C1667 (1 mention) - the report calls it "FDA-approved for plague"; NCIT calls it RG 14620
  • NCIT:C480 (1 mention) - the report calls it "Treatment/PEP"; NCIT calls it Estramustine Phosphate Sodium
  • NCIT:C328 (1 mention) - the report calls it "Meningitis, alt"; NCIT calls it Caffeine

Terms named inconsistently

The report gives these identifiers more than one name of its own:

  • CL:0000235 - called "macrophage", "Cell populations targeted:** phagocytes — macrophages"