Plague is an acute febrile disease caused by infection with Yersinia pestis. Human cases are infrequent and are curable with antibiotics. Plague is, however, one of the most virulent and potentially lethal bacterial diseases known, and fatality rates remain high among patients who are not treated in the early stages of infection. Plague occurs in widely scattered foci in Asia, Africa, and the Americas (Fig. 152-1), where its usual hosts are various wild rodents and human-associated rats. Infection is transmitted to humans typically by flea bite and infrequently by direct contact with infected animal tissues or by airborne droplet
