Rickettsial diseases.

Rickettsiae are a rather diverse collection of organisms with several differences; this prohibits their description as a single homogenous group. Rickettsiae are maintained in nature through a cycle involving reservoir in mammals and arthropod vectors. The public health impact of these on lives or productivity lost is largely unmeasured, but suspected to be quite high worldwide. The diseases caused by Rickettsia and Orientia species are often collectively referred to as rickettsioses. Coxiella burnetii, the agent of Q fever is still frequently categorized as rickettsial disease. New or emerging rickettsial diseases; tickborne lymphadenopathy (TIBOLA) and Dermacentor-borne-necrosis-eschar- lymphadenopathy (DEBONEL) related to Rickettsia slovaca infection have been described. The rickettsial diseases were believed to have disappeared from India are reemerging and recently their presence has been documented in at least eleven states of our country. Many cases of rickettsial diseases go undiagnosed due to lack of diagnostic tools. Greater clinical awareness, a higher index of suspicion, better use of available diagnostic tools would increase the frequency with which rickettsial diseases are diagnosed.