typhus, scrub

typhus, scrub A mite-borne infectious disease that is caused by the microorganism Orientia (formerly Rickettsia) tsutsugamushi. Characteristic symptoms include fever, headache, a raised (macular) rash, swollen glands (lymphadenopathy), and a dark crusted ulcer, called an eschar or tache noire, at the site of the chigger (mite larva) bite. Scrub typhus occurs in the area bounded…

typhus, murine

typhus, murine An acute infectious disease characterized by fever, headache, and rash that are similar to, but milder than, those in epidemic typhus. Murine typhus is caused by the microorganism Rickettsia typhi (mooseri) and transmitted to humans by rat fleas (Xenopsylla cheopis). The animal reservoir includes rats, mice, and other rodents. Murine typhus occurs sporadically…

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…

typhus, African tick

typhus, African tick One of the tick-borne rickettsial diseases of the eastern hemisphere, similar to Rocky Mountain spotted fever but less severe. Symptoms include fever, a small ulcer (tache noire) at the site of the tick bite, swollen glands near the site of the tick bite (satellite lymphadenopathy), and a red, raised (maculopapular) rash. Also…