Plague

Alternative names:

bubonic plague; pneumonic plague; septicemic plague

Definition:

An infection caused by the organism Yersinia pestis which occurs in wild rodents and is transmitted to humans.

Causes, incidence, and risk factors:

Plague is transmitted among rodents and to humans by flea bite or ingestion of the feces of fleas. It can also be transmitted human to human when a plague victim develops pneumonia and spreads infected droplets by coughing. An epidemic may be started this way. Endemic areas in the U.S. are California, Utah, Arizona, Nevada, and New Mexico. Two types of plague, bubonic and pneumonic, can occur. The incubation period is 2 to 10 days but may be as short as a few hours for pneumonic plague.

Risk factors include a recent flea bite and occupational or environmental exposure to rodents. The incidence of the disease is rare.