Serological evidence of Rickettsia in horses from a semi-arid Brazilian region.

Ila Ferreira Farias,Mauricio Claudio Horta,Maria Carolina De Azevedo Serpa,Flávio Silva Palha,Glauber Meneses Barboza De Oliveira,Eline Almeida Rodrigues De Souza,Marcelo Bahia Labruna

doi:10.1590/s1984-29612021011

Abstract

Brazilian spotted fever (BSF) is a common tick-borne disease caused by Rickettsia rickettsii. Horses are the primary hosts of the main vector, Amblyomma sculptum, and are considered efficient sentinels for circulation of Rickettsia. Therefore, the aim of this study was to detect antibodies reactive to R. rickettsii antigens in horses from a non-endemic area in the north-central region of Bahia state, Brazil. Blood samples and ticks were collected from 70 horses from the municipalities of Senhor do Bonfim, Antônio Gonçalves, Pindobaçu, and Campo Formoso. The sera obtained were tested by an indirect immunofluorescence assay to detect anti-Rickettsia antibodies. Overall, 5.7% (4/70) of the horses reacted to R. rickettsii antigens. Ticks were collected from 18.6% (13/70) of the horses and were identified as A. sculptum and Dermacentor nitens. Despite being a non-endemic area, seropositive animals were identified in our study, suggesting circulation of rickettsial agents in the region. This is the first serological survey of this agent in horses from the north-central region of Bahia, and further studies are needed to understand the epidemiology of BSF in these locations.

Highlights

A Febre Maculosa Brasileira (FMB) é uma importante zoonose causada por Rickettsia rickettsii, sendo seu vetor o Amblyomma sculptum
Brazilian spotted fever (BSF) is a common tick-borne disease caused by the bacterium Rickettsia rickettsii and is considered the most important rickettsial disease in Brazil due to > 50% fatality rates (Luz et al, 2019)
In addition to BSF, cases of a mild spotted fever caused by the bacterium Rickettsia parkeri have been reported in humans in different areas of the Atlantic Forest biome

Summary

Introduction

A Febre Maculosa Brasileira (FMB) é uma importante zoonose causada por Rickettsia rickettsii, sendo seu vetor o Amblyomma sculptum. Brazilian spotted fever (BSF) is a common tick-borne disease caused by the bacterium Rickettsia rickettsii and is considered the most important rickettsial disease in Brazil due to > 50% fatality rates (Luz et al, 2019). In addition to BSF, cases of a mild spotted fever caused by the bacterium Rickettsia parkeri have been reported in humans in different areas of the Atlantic Forest biome.

Objectives

Results

Conclusion