BUBONIC PLAGUE

The most common form of the plague named for the characteristic buboes which are enlarged lymph nodes ("swollen glands") in the groin that are tender and painful. Lymph nodes may be similarly affected in the armpits (axillae), neck and elsewhere. Other features of the bubonic plague include headache, fever, chills, and weakness. Bubonic plague is caused by a bacterium (Yersinia pestis) which is transmitted to humans from infected rats by the oriental rat flea. Bubonic plague can lead to "black death" characterized by gangrene of the fingers, toes, and nose.