Brazilian spotted fever in Caratinga, Minas Gerais.

Introduction: The order Rickettsiales comprises a group of obligatory intracellular parasites, responsible for causing diseases known as rickettsial diseases. In Brazil, the most common rickettsial disease is the Brazilian spotted fever (FMB). Objectives: to determine the level of FMB endemicity in the city of Caratinga, Minas Gerais, in different epidemiological moments. Methods: epidemiological and serological surveys in residents from the most affected neighborhoods by the 1992 FMB outbreak and serological survey in domestic animals; in addition to serological survey in domestic animals and polymerase chain reaction in arthropod vectors collected in a new visit to the site in 2002. Results: in the first epidemiological survey carried out in 1992, 62.3% of the surveyed families reported contact with pastures. In the serological survey in humans, 2.1% of tested samples showed reactivity to Rickettsia rickettsii in the indirect immunofluorescence reaction (RIFI). In the serological survey on animals, conducted in 1993, 53.4% of equines and 25.0% of dogs were reactive for R. Rickettsii in RIFI. In a new visit to the site, over the period of 2002-2003, 13.4% of pools of DNA from examined arthropods and 17.0% of equine sera demonstrated positive results for R. rickettsii. Conclusions: the municipality of Caratinga can be considered, at the time, as a low transmission area remaining the recommendation to keep the epidemiological and acarological surveillance system active on the site and region.