- Plague is an acute and potentially fatal bacterial infection
that affects humans and most mammals. It is caused by Yersinia
pestis, a Gram-negative, bipolar-staining, pleomorphic
- A bioterrorism-related release of Y. pestis could
result in the infection of not only humans but also domestic
and peri-domestic animals via:
- inhalation of the primary aerosol,
- ingestion of food or water exposed to the primary aerosol,
- ingestion of another infected animal, or
- flea bite from an infective flea (that had previously
fed on a bacteremic animal).
- Natural transmission cycles involving wild rodents and their
fleas can be found in many regions of the western United States.
- Occasionally, naturally occurring plague causes widespread
outbreaks or epizootics among rodent populations.
- While it appears that virtually any mammal can be infected
with plague bacteria, some species do not develop clinical signs
of illness following infection and are unlikely to pose great
risks to humans.