Molecular detection and characterization of hepatitis E virus in naturally infected pigs from Brazilian herds

The aim of this study was to investigate the presence of swine hepatitis E virus (HEV) from pigs of different production categories and from different pig farms in South Brazil. A total of 170 porcine faecal samples from breeder sows, boars, suckling piglets, weaned and growing pigs were collected from 14 pig farms. The faecal samples were screened by nested RT-PCR using primers targeting the ORF2 region of HEV genome. The samples that were positive from this screening were used in a nested RT-PCR targeting the ORF1 region. The screening detected HEV RNA in 62.5% of the pig farms and in 15.3% of the faecal samples. In 15 faecal samples, it was possible to amplify the HEV RNA with both the ORF1 and ORF2 regions. The phylogenetic analyses obtained for both ORFs confirmed that all of the Brazilian swine HEV isolates clustered with genotype 3b, the same genotype described previously in humans in Brazil.