Plague is a potentially life-threatening disease caused by a bacterium (Yersinia pestis) that originates from rodents. Fleas on rodents can also spread the disease.

There are three types of plague:

Pneumonic plague affects the lungs. An infected person can spread the disease by sneezing, coughing, or otherwise releasing saliva droplets that are inhaled by another person. If a person does not get antibiotics within 24 hours of the first symptoms, pneumonic plague can cause respiratory failure, shock, and rapid death. Symptoms usually include fever, weakness, and shortness of breath.

Bubonic plague spreads through the bite of a flea infected with the plague bacterium. Symptoms of bubonic plague include fever, fatigue, and swollen, tender lymph glands in the neck, armpits, or groin.

Septicemic plague infects people when the plague bacterium comes in contact with the tissues lining the nose or throat (mucous membranes). This is caused by eating contaminated food, by touching a contaminated object and then touching the nose or mouth without first washing the hands, or by breathing in droplets of contaminated saliva. Symptoms of septicemic plague include fever, abdominal pain, purplish skin, and shock.

Prevention of the plague requires adequate sanitation. After diagnosis of the plague, the infected person is isolated from others to prevent the spread of the disease. Treatment includes antibiotics, rest, fluids, and pain medications.