Phylogenetic analysis of Hepatitis E virus strains isolated from slaughter-age pigs in Colombia

Hepatitis E virus (HEV) is a zoonotic virus that causes acute hepatitis in humans, and can be transmitted via the fecal–oral route. Pigs are considered to be a reservoir for this infection—mainly where the disease is not endemic. In a previous study conducted in Antioquia, which is a region in Colombia where the production and consumption of pork meat is higher than in the rest of the country, the presence of anti-HEV IgG-type antibodies was reported in slaughter-age pigs. Aiming to identify the HEV genotype circulating in swine, animal liver, and feces samples from five swine cattle slaughterhouses located in six different sub-regions of Antioquia were collected. A nested RT-PCR (nRT-PCR) was used in order to amplify the HEV ORF-1 (170 bp) and ORF-2 (348, and 958 bp). The amplicons yielded in this study were sequenced, and a molecular phylogeny analysis based on the maximum likelihood method, including HEV sequences reported in several countries, was performed. Phylogeny analysis revealed that HEV amplification fragments from Antioquia's pigs were grouped in three clades within the sub-genotype 3a without a specific geographical structure, and were also genetically related to Japanese and American HEV sequences. This analysis provides the first approach on the genetic diversity and circulation dynamics of HEV in Colombian herds.