[Rickettsiae detection in Amblyomma ticks (Acari: Ixodidae) collected in the urban area of Campinas City, SP]

Abstract

The city of Campinas is located in an endemic area for Brazilian spotted fever in São Paulo State, where several cases have recently occurred. Capybaras have been associated with the cycle of this disease, for they present positive serology and serve as host for ticks of the genus Amblyomma, the main vectors of Brazilian spotted fever. Ticks were collected both from Capybaras and from the vegetation in the city park Lago do Café, located in the urban area of Campinas City, SP, a site associated with suspected human cases of Brazilian spotted fever. The ticks collected were examinated for the presence of rickettsiae using polymerase chain reaction and the haemolymph test. Through analysis of the gene gltA nucleotide sequence, adults of Amblyomma cajennense and Amblyomma cooperi were found to be infected with the non pathogenic Rickettsia bellii. However, no rickettsiae of the Spotted Fever Group were detected. These results indicate that the role of capybaras as reservoirs of rickettsiae of the Spotted Fever Group is still uncertain and further studies are required.