Plague Home > Bacteria That Causes the Bubonic Plague
The bacteria that causes the bubonic plague is usually spread through the bite of an infected rodent or flea. This bacteria is called Yersinia pestis and infects 1,000 to 3,000 people each year. Within two to six days of exposure to the bacteria that causes the bubonic plague, symptoms may develop, including headache, chills, fever, and swollen lymph glands.
Bubonic plague is the most common form of plague. The bacteria that causes the bubonic plague is called Yersinia pestis. This bacteria also causes the other two forms of plague: septicemic plague and pneumonic plague (see Types of Plague).
Yersinia pestis are Gram-negative bacteria found in certain parts of the world. This bacteria causes about 1,000 to 3,000 plague cases each year, mostly in Africa, Asia, and South America. Between 10 to 20 cases occur annually in southwest areas of the United States.
Yersinia pestis is found most commonly in rats, but is occasionally found in other animals. Some of these animals include:
- Prairie dogs
- Wood rats
Usually, the bacteria that causes the bubonic plague is contracted when someone is bitten by an infected flea or rodent. In rare cases, it is possible for a piece of contaminated clothing or other material used by an infected person to transmit bacteria through a cut or other opening in your skin and infect you. Bubonic plague is rarely spread from person to person.
Yersinia pestis bacteria begin to multiply once they reach the lymph nodes. (The lymph or lymphatic system is a major component of your body's immune system. The organs within the lymphatic system are the tonsils, adenoids, spleen, and thymus.)
Within two to six days of exposure to the bacteria that causes the bubonic plague, symptoms may develop, such as:
- Swollen, tender lymph glands (called buboes, hence the name bubonic).