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

Alternative Names

Bubonic plague; Pneumonic plague; Septicemic plague

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 (especially rabbits, squirrels, or prairie dogs; or scratches or bites from infected domestic cats). The incidence of the disease is rare.

Signs and tests

These tests may indicate a plague infection:

Culture of bubo

Culture of sputum

Blood culture

Lymph node culture

Treatment

Immediate treatment with antibiotics such as streptomycin, chloramphenicol, or tetracycline is indicated. Oxygen,

intravenous fluids, and respiratory support are additional treatments. Patients with pneumonic plague are strictly isolated from other patients. People who have had contact with anyone infected by pneumonic plague are observed closely and are given antibiotics as a preventive measure. Note: Oral tetracycline is usually not prescribed for children until after all the permanent teeth have erupted. It can permanently discolor teeth that are still forming.

Expectations (prognosis)

Half of bubonic plague victims die if not treated, and almost all victims of pneumonic plague die if not treated. Treatment reduces the death rate to 5%.

Complications

Some complications include septicemia (blood poisoning).

Calling your health care provider

Call your health care provider if symptoms develop after exposure to fleas or rodents, especially if you live or have visited in an area where plague occurs frequently ( endemic areas). Endemic areas in the U.S. are California, Arizona, Utah, Nevada, and New Mexico.

Prevention

Rat control and surveillance of the disease in the wild rodent population are the main measures used to control the risk of epidemics. A vaccination is available for high-risk workers, but its effectiveness is not clearly established.