Hepatitis E virus genotype 4 in a pig farm, Italy, 2013.

Zoonotic strains of hepatitis E virus (HEV) in Europe have been reported to belong to genotypes 3 and 4. In 2012 and 2013, 57 pig farms in Northern Italy that had previously resulted seropositive for HEV were surveyed for the presence of the virus, with positive samples subsequently genotyped. Hepatitis E RNA was identified in 17/57 (29·8%) seropositive farms. Phylogenetic analysis demonstrated that distinct subtypes of genotype 3 were circulating in the north-east of Italy; as well, for the first time in the Italian swine population, genotype 4 was identified and attributed to subtype d.