Plague
Educational information. Individual clinical review of this presentation by Dr. Ehsan is not yet documented. It does not replace personal medical evaluation.
Source: MedlinePlus, National Library of Medicine. Read the original source
MedlinePlus data edition September 26, 2026. Imported September 27, 2026. These dates do not indicate a new clinical review of the article.
Plague is an infection caused by the bacterium Yersinia pestis. The bacteria are found mainly in rats and in the fleas that feed on them. People and other animals can get plague from rat or flea bites. In the past, plague destroyed entire civilizations. Today plague is uncommon, due to better living conditions and antibiotics.
There are three forms of plague:
- Bubonic plague causes the tonsils, adenoids, spleen, and thymus to become inflamed. Symptoms include fever, aches, chills, and tender lymph glands.
- In septicemic plague, bacteria multiply in the blood. It causes fever, chills, shock, and bleeding under the skin or other organs.
- Pneumonic plague is the most serious form. Bacteria enter the lungs and cause pneumonia. People with the infection can spread this form to others. This type could be a bioterror agent.
Lab tests can diagnose plague. Treatment is a strong antibiotic. There is no vaccine.
Symptoms, tests and care options
Further reading selected by MedlinePlus. Links open the original organizations’ websites.
- Diagnosing Plague · Centers for Disease Control and Prevention
- Signs and Symptoms of Plague · Centers for Disease Control and Prevention
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