Types of Plague
There are three different types of plague: bubonic plague, septicemic plague, and pneumonic plague. The most common type is bubonic plague. Septicemic plague occurs when the Yersinia pestis bacteria (the organism responsible for the disease) multiply in the blood. Pneumonic plague is the most serious of the three types of plague. It occurs when plague bacteria infect the lungs, causing pneumonia.
Yersinia pestis (the bacteria that causes plague) can cause three different types of plague in people:
With bubonic plague, the most common form of the disease, bacteria infect the lymph system and become inflamed. (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.)
Usually, bubonic plague is contracted through the bites of an infected flea or rodent. In rare cases, Yersinia pestis bacteria may enter through an opening in the skin from a piece of contaminated clothing or other material used by an infected person. Bubonic plague is rarely spread from person to person.
Within two to six days of exposure to the plague bacteria, flu-like symptoms may develop, such as:
- Swollen, tender lymph glands (called buboes, hence the name bubonic).