Molecular evidence of Anaplasma phagocytophilum and Theileria equi coinfection in horses from Rio de Janeiro, Brazil.

The present study aims to determine the frequencies of and antibodies among horses from the state of Rio de Janeiro, Brazil, and to detect the presence of DNA of these pathogens through molecular methods. A total of 98 serum samples of horses from the municipality of Seropedica were tested by indirect immunofluorescence antibody (IFA) to detect anti- and anti- IgG antibodies. In addition, quantitative real-time PCR (qPCR) was used to detect these pathogens in the DNA extracted from the whole blood and buffy coat of horses. Bivariate analysis and odds ratio were performed to verify the possible association between positivity and characteristics related to the horses. As evaluated by IFA and qPCR, the frequency of animals that tested positive for was 89.8% ( = 88/98) and 91.8% ( = 90/98), whereas was 17.4% ( = 17/98) and 1.0% ( = 1/98), respectively. Serological evidence of exposure to and was observed in 16.3% ( = 16/98) of the horses; however, exposure was confirmed by qPCR in only 1.0% ( = 1/98). No statistical association was found in the bivariate and odds ratio analysis. This is the first study reporting the molecular detection of DNA in horses from the state of Rio de Janeiro, and also the coinfection of and in a horse from Brazil confirmed by molecular methods. Equine granulocytic anaplasmosis is circulating in Brazilian horses, together with , and should be included in the differential diagnosis of tick-borne diseases.