Dados do Trabalho

Título

SEROSURVEY OF RICKETTSIAE ANTIBODIES IN INDIGENOUS COMMUNITIES FROM BRAZIL

Introdução

Brazilian Spotted Fever (BSF) is a zoonotic disease transmitted by ticks of the genus Amblyomma, which have a wild habitat and high anthropophily. The etiological agent of classic BSF is Rickettsia rickettsii, being considered one of the most lethal agents in the world, reaching 85% lethality when untreated. In Brazil, the indigenous population residing in forested areas are particularly vulnerable to this disease, with the proximity to wild reservoirs and the vector as a risk factor, in addition with difficult access to medical care, which can determine a late diagnosis with an unfavorable prognosis.

Objetivo (s)

To investigate the presence of antibodies against rickettsiae in indigenous population living in communities in the south and southeast regions of Brazil.

Material e Métodos

Serum samples were collected from nine communities between 2020 and 2022, being five from the state of Paraná and four from São Paulo, in areas of remaining vegetation in Atlantic Forest and Cerrado biomes, respectively. The serum samples were tested by Immunofluorescence Assay (IFA) for four species of rickettsiae: R. rickettsii, Rickettsia parkeri, and Rickettsia amblyommatis, belonging to the Spotted Fever Group (SFG); and Rickettsia bellii, whose pathogenicity is still unknown.

Resultados e Conclusão

Overall, 55/444 (12,39%) of the indigenous were seroreactive to at least one of the four Rickettsia spp. antigens, with 22/55 (40%) from Paraná and 33/55 (60%) from São Paulo, with titers ranging from 64 to 256. Our results demonstrate the circulation of different species of rickettsiae in indigenous populations, determining risks for the occurrence of classic BSF, and emphasizing the need for promoting awareness and prevention of tick-borne diseases in these populations.

Palavras-chave

Indigenous; Brazilian Spotted Fever; Rickettsiae; Zoonoses; Ticks.

Agradecimentos

Brazilian National Council for Scientific and Technological Development - CNPq (404687/2021-0).