Scanning electron micrograph showing Yersinia pestis, which causes bubonic plague


Plague, caused by the bacterium Yersinia pestis, is a disease that affects humans and other mammals. People typically get infected after being bitten by a rodent flea that is carrying the bacterium or by handling a plague-infected animal. Although the disease killed millions in Europe during the Middle Ages, antibiotics effectively treat plague today. Without prompt treatment, plague can cause serious illness or death. Human plague infections continue to occur in the western United States, but significantly more cases occur in parts of Africa and Asia.

Why Is the Study of Plague a Priority for NIAID?

Plague is a category A pathogen which are those organisms/biological agents that pose the highest risk to national security and public health because they can be easily disseminated or transmitted from person to person, result in high mortality rates and have the potential for major public health impact, might cause public panic and social disruption, and require special action for public health preparedness.

How Is NIAID Addressing This Critical Topic?

NIAID conducts and supports research on the diagnosis, prevention, and treatment of infections caused by microbes, including those that have the potential for use as biological weapons. The research program to address biodefense includes both short- and long-term studies targeted at designing, developing, evaluating, and approving specific tools (diagnostics, drugs, and vaccines) needed to defend against possible bioterrorist-caused disease outbreaks.

To learn about risk factors for plague and current prevention and treatment strategies visit the MedlinePlus plague site.

Biology & Genetics

NIAID-supported investigators sequenced the genome of the strain of Yersinia pestis that was associated with the second pandemic of plague, including the Black Death. This will provide a valuable research resource to scientists for identifying new targets for vaccines, drugs, and diagnostics for this deadly pathogen.

Read more about the biology and genetics of Yersinia pestis


NIAID is working with the U.S. Department of Defense, the Centers for Disease Control and Prevention, and the U.S. Department of Energy to develop a vaccine that protects against inhalationally acquired pneumonic plague


NIAID-funded scientists have developed a rapid diagnostic test for pneumonic plague that can be used in most hospitals. This will allow healthcare providers to quickly identify and isolate the pneumonic plague patient from other patients and enable healthcare providers to use appropriate precautions to protect themselves.

Treatment & Prevention

NIAID is working with the U.S. Department of Defense, the Centers for Disease Control and Prevention, and the U.S. Department of Energy to develop promising antibiotics and intervention strategies to treat and prevent plague infection.

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