typhus

any one of a group of infections caused by RICKETTSIA and characterized by severe headache, a widespread rash, prolonged high fever, and delirium. They all respond to treatment with chloramphenicol or tetracyclines. Epidemic typhus (also known as classical or louse-borne typhus) is caused by infection with Rickettsia prowazekii transmitted by lice. It was formerly very prevalent in overcrowded insanitary conditions (as during wars and famines), with a mortality rate approaching 100%. Endemic typhus (murine or flea-borne typhus) is a disease of rats due to Rickettsia mooseri; it can be transmitted to humans by rat fleas, causing a mild typhus fever. There are in addition several kinds of tick typhus (in which the rickettsiae are transmitted by ticks), including ROCKY MOUNTAIN SPOTTED FEVER , and typhus transmitted by mites.