MedlinePlus Medical Encyclopedia: Plague

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Plague

Contents of this page:
Illustrations Alternative names Definition Causes, incidence, and risk factors Symptoms Signs and tests	Treatment Expectations (prognosis) Complications Calling your health care provider Prevention

Illustrations

Flea

Flea bite - close-up

Antibodies

Alternative names Return to top

Bubonic plague; Pneumonic plague; Septicemic plague

Definition Return to top

Plague is an infection caused by the organism Yersinia pestis. It is carried by wild rodents and transmitted to humans.

Causes, incidence, and risk factors Return to top

Plague is transmitted among rodents and to humans by flea bite or ingestion of the feces of fleas. It can also be transmitted from human to human when a plague victim develops pneumonia and spreads infected droplets by coughing. An epidemic may be started this way.

Plague is rare in the United States, but areas where the disease is known to occur include parts of California, Utah, Arizona, Nevada, and New Mexico.

There are two types of plague, bubonic and pneumonic. The incubation period is 2 to 10 days but may be as short as a few hours for pneumonic plague.

Risk factors for plague 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).

Symptoms Return to top

BUBONIC PLAGUE

Sudden onset of high fever
Chills
General discomfort, uneasiness, or ill feeling (malaise)
Muscular pains
Severe headache
Smooth, oval, reddened, painful swellings of swollen lymph glands called buboes in the groin, armpits, neck, or elsewhere in the body. Pain may occur in the area before the swelling; the most common area is in the groin
Seizures

PNEUMONIC PLAGUE

Severe cough
Frothy, bloody sputum
Difficulty breathing

SEPTICEMIC PLAGUE

Fever
Extreme illness
Nausea, vomiting, diarrhea, and abdominal pain
Low blood pressure
Blood clotting problems
Failure of several or all organ systems

Signs and tests Return to top

These tests may indicate a plague infection:

Treatment Return to top

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) Return to top

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 Return to top

Some complications include septicemia (blood poisoning).

Calling your health care provider Return to top

Call your health care provider if symptoms develop after exposure to fleas or rodents, especially if you live in or have visited in an area where plague occurs.

Prevention Return to top

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.

Update Date: 8/11/2003

Updated by: Daniel Levy, M.D., Ph.D., Infectious Diseases, Greater Baltimore Medical Center, Baltimore, MD. Review provided by VeriMed Healthcare Network.

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