Plague

Plague is an infection caused by Yersinia pestis, a Gram-negative bacterium within the genus Yersinia ^[1][3]. The disease is described in the sources as zoonotic and associated with stable environmental foci, reflecting ongoing circulation among mammals, fleas, and contaminated soils ^[1]. Source-backed detail on taxonomic subtypes or formal clinical classification beyond this etiologic description is not yet available ^[1][3].

The sources associate plague with painful, enlarged lymph nodes or buboes, and with septicemic dissemination following initial infection ^[1][2]. One review describes afflicted persons as developing high fevers and suppurative buboes, and notes that some historical cases died quickly ^[2]. Primary pneumonic plague is reported after droplet inhalation following close contact with infected mammals ^[1]. The sources also note pharyngeal and gastrointestinal plague after consumption of contaminated raw meat, but further source-backed detail on course, complications, or relative frequency is not yet available ^[1].

Plague is reported to have a long human history, with acknowledgement of infection in human populations for at least 5,000 years in Eurasia ^[1]. The sources describe stable foci in the Americas, Africa, and Eurasia, and note endemicity in Madagascar, Congo, and Peru ^[1][2]. Historical accounts in the provided material also link plague to major epidemics such as the fourteenth-century Black Death in Europe ^[2]. Environmental persistence is described as depending on contaminated soils, susceptible burrowing and nonburrowing mammals, and their associated fleas ^[1].

Transmission is said to occur mainly through infected flea bites, with fleas acting as the principal route between hosts ^[1]. The sources also describe droplet inhalation after close contact with infected mammals as the mechanism for primary pneumonic plague ^[1]. A history review additionally mentions rats carrying fleas, and notes proposed alternative routes including human body lice and infected grain, but these are presented as theories rather than established mechanisms in the provided material ^[2].

The source material does not provide a formal risk-group list. It does indicate heightened ecological exposure for people in or near established plague foci and for those encountering infected fleas, susceptible mammals, or close contact with infected mammals ^[1]. It also notes that plague persists through interactions among contaminated soils, burrowing and nonburrowing mammals, and associated fleas, implying greater exposure risk in those ecological settings ^[1].

The sources indicate that mandatory primary prevention relies on active surveillance of established plague foci and ectoparasite control ^[1]. Outbreak control is also described as depending on point-of-care diagnosis, early antibiotic treatment, and confinement measures, though the preventive emphasis in the provided sources is strongest for surveillance and vector control ^[1]. Source-backed detail on vaccination, routine chemoprophylaxis, or other specific community prevention measures is not yet available ^[1][2].

For surveillance purposes, plague should be read as a zoonosis with persistent ecological foci rather than a disease eliminated between outbreaks ^[1][2]. The provided literature emphasizes monitoring of known foci, flea and host ecology, and recognition of transmissible clinical syndromes such as bubonic and pneumonic plague ^[1]. Because the disease can present through flea-borne, respiratory, or alimentary exposure pathways, surveillance should integrate human case detection with ecological and vector monitoring where available ^[1][2].

1. 1 Barbieri R et al. Yersinia pestis: the Natural History of Plague. Clin Microbiol Rev. 2020 Dec 16. PMID: 33298527. doi: 10.1128/CMR.00044-19. PubMed: https://pubmed.ncbi.nlm.nih.gov/33298527/
2. 2 Glatter KA et al. History of the Plague: An Ancient Pandemic for the Age of COVID-19. Am J Med. 2021 Feb. PMID: 32979306. doi: 10.1016/j.amjmed.2020.08.019. PubMed: https://pubmed.ncbi.nlm.nih.gov/32979306/
3. 3 Seabaugh JA et al. Pathogenicity and virulence of Yersinia. Virulence. 2024 Dec. PMID: 38389313. doi: 10.1080/21505594.2024.2316439. PubMed: https://pubmed.ncbi.nlm.nih.gov/38389313/
4. 4 Plague: Yersinia Pestis Infection. Bacterial Diseases. 2020. doi: 10.2174/9789811473760120010017. DOI: https://doi.org/10.2174/9789811473760120010017
5. 5 Finally, plague is plague. Clinical Microbiology and Infection. 2012. doi: 10.1111/j.1469-0691.2011.03745.x. DOI: https://doi.org/10.1111/j.1469-0691.2011.03745.x
6. 6 Plague upon plague. Nature. 1990. doi: 10.1038/343193b0. DOI: https://doi.org/10.1038/343193b0

ICD-10

A20

ICD-11

1B90

Total cases

174

Total deaths

14

Peak month

2007-02

Coverage

6 reporting countries · 2007-01-01 → 2026-06-20