Soroepidemiologia e pesquisa de riquétsias no sangue de cães e equinos como indicador da circulação de riquétsias na região do Médio Paraibuna, Minas Gerais, Brasil

Abstract

Spotted Fever is a zoonotic disease caused by bacteria of the genus Rickettsia. The natural relationship between vectors and their vertebrate hosts during the enzootic cycle, may vary in time and space, showing an epidemiological complexity that must be investigated and monitored as a key indicator for the actions of public policy in the prevention and control of human cases. This way, dogs and horses are sentinels, indicating the movement of Rickettsia sp. in a region and serving as dispersers of vectors, allowing the amplification of a focus or establishing new foci. To better understanding of the movement of Rickettsia sp. in the urban area of Juiz de Fora, Minas Gerais, Brazil , endemic area for spotted fever, blood of dogs and horses from different regions were tested by indirect immunofluorescence assay (IFA ) and Polymerase Chain Reaction ( PCR ). Samples resulted 12.75% (31/ 243) of dogs and 23.68 % ( 9/38 ) equine with titers ≥ 1:64. PCR primers were used to amplify fragments of the gltA and ompA genes, no positive results. The highest number of positive dogs occurred in the east region, an area with human cases reported between 2007 and 2008. However, the highest prevalence and concentration of high titers in dogs was reported in the northern region, an area with confirmed recent cases ( 2012 ). Similar results were obtained from equine, confirming a higher activity in the foci of the region. Areas with no human case presented animals with high titers, suggesting a potential risk for the population. The results confirm the role of dogs and horses in the enzootic cycle of Rickettsia in the region studied and its potential as epidemiological indicators for the investigation of cases and monitoring of spotted fever in the environment.