Molecular prevalence of equine parvovirus hepatitis in healthy horses from the Northern region of the state of Rio Grande do Sul, Brazil.

The equine parvovirus hepatitis (EqPV-H) was initially linked to fatal cases of equine serum hepatitis but, more recently, it has also been detected in sick or asymptomatic horses around the world, including in a limited number of horses in southeastern Brazil. In this study we aimed to assess the prevalence of EqPV-H DNA in the serum of healthy horses in the northern region of Rio Grande do Sul state, Brazil. For this purpose, we used 1000 serum samples collected from horses from 40 municipalities and organized them into 200 pools of five samples each, based on origin and age. Using a nested polymerase chain reaction (nPCR), we detected the EqPV-H DNA in 69 of the pools representing 34.5% of the total, with positive samples found in 26 (65%) of the municipalities. The prevalence did not differ significantly by age group (p = 0.52). The nucleotide and phylogenetic analysis conducted with the partial NS1 sequence obtained from five serum pools revealed a high degree of genetic conservation with previous worldwide isolates, indicating specific nucleotide variability present in strains from Brazil and Argentina but absent in strains from other countries. Our study provides the first evidence that EqPV-H is widespread in horses in the region and it should be considered in suggestive clinical cases of hepatitis.