Last Reviewed: October 2011

What is plague?

Plague is a severe disease caused by an infection with a type of bacteria that is found in rodents and their fleas. Plague can exist in different forms in people and can require strict isolation and disinfection procedures. The disease is relatively rare in the United States and exposure is primarily limited to the western and southwestern parts of the country.

Who gets plague?

People working in or visiting areas with infected rodents are at greater risk of contracting this disease. There have been no reports of plague in New York State. However, exposures in the western U.S. or overseas have occasionally resulted in cases or need for investigations in the eastern U.S.

How is plague spread?

The most common means of transmission is by exposure to infected fleas. Other important sources include the handling of infected animals (especially cats, rabbits and rodents), airborne droplets from humans or household pets with plague pneumonia or by laboratory exposure.

What are the symptoms of plague?

The initial symptom is usually a swollen, inflamed and tender lymph gland in the body near where the infected flea bit the person (a bubo). Fever is usually present. With or without a bubo, the disease may progress to a generalized blood infection, with non-specific flu-like symptoms. Pneumonia may also develop. People or animals with pneumonic plague may transmit the disease to other people by coughing.

How soon do symptoms occur?

Symptoms usually begin within one to six days after exposure to the plague bacteria.

Does past infection with plague make a person immune?

Immunity after plague recovery is variable and may not provide complete protection.

What is the treatment for plague?

Certain antibiotics such as streptomycin, tetracyclines and chloramphenicol are effective in treating the disease.

What can be done to prevent the spread of plague?

  • The patient, his/her clothing and baggage should be treated to kill all fleas that may be attached.
  • Patients or animals with pneumonic plague should be quarantined until three full days of antibiotic treatment have been administered.
  • When human or animal cases have been identified, efforts to control the rodent and flea populations by the use of rodenticides and insecticides should be used.
  • Wild rodents such as prairie dogs imported from the western U.S. should not be used as pets.