Rickettsia(e) Health Dictionary

The general term given to a group of microorganisms which are intermediate between BACTERIA and viruses (see VIRUS). They are the causal agents of TYPHUS FEVER and a number of typhus-like diseases, such as ROCKY MOUNTAIN SPOTTED FEVER, Japanese River fever, and scrub typhus. These micro-organisms are usually conveyed to man by lice, ?eas, ticks, and mites.

Visceral rickettsia is a disease transmitted by mites from an infected house mouse, which occurs in the USA, South Africa, Korea and the former Soviet Union. The causal organism is Rickettsia akari. The incubation period is 7–14 days and the characteristic features are fever, headache, and a non-irritating rash on the face, trunk and extremities. The disease is non-fatal and responds rapidly to TETRACYCLINES.... rickettsia

pl. n. (sing. rickettsia) a group of very small nonmotile spherical or rodlike parasitic bacteria that cannot reproduce outside the bodies of their hosts. Rickettsiae infect arthropods (ticks, mites, etc.), through which they can be transmitted to mammals (including humans), in which they can cause severe illness. The species Rickettsia akari causes *rickettsial pox, R. conorii, R. prowazekii, R. tsutsugamushi, and R. typhi cause different forms of *typhus, R. rickettsii causes *Rocky Mountain spotted fever, and Coxiella burnetii causes *Q fever. —rickettsial adj.... rickettsiae

a disease of mice caused by the bacterium Rickettsia akari and transmitted to humans by mites: it produces chills, fever, muscular pain, and a rash similar to that of *chickenpox. The disease is mild and runs its course in 2–3 weeks. See also typhus.... rickettsial pox