typhus, epidemic

typhus, epidemic A severe, acute disease with prolonged high fever up to 40° C (104° F), intractable headache, and a pink-to-red raised rash. The cause is a microorganism called Rickettsia prowazekii, which is found worldwide and is transmitted by lice. The lice become infected on typhus patients and transmit illness to other people. The mortality increases with age, and more than half of untreated persons age 50 or older die. Also known as European, classic, or louse-borne typhus and as jail fever. See also rickettsial diseases.