Surveillance of Hepatitis E virus (HEV) in swine farms and farmers and first identification of genotype 4 in Italy.

Abstract Hepatitis E is an emerging zoonotic disease caused by a positive ssRNA virus, Hepatitis E virus (HEV). In Europe, pigs are the main reservoir. Genotype 3 of HEV (HEV3) has a worldwide distribution while genotype 4 (HEV4) mostly occurs in Asia. However, HEV4 has recently been isolated in pigs and humans in Europe. Abstract methods During 2011-2014, a monitoring plan was performed to evaluate the prevalence of HEV infection in different human populations and pigs in Italy. Assuming an expected herd-level seroprevalence of 50%, 175 pig farms were sampled. To detect at least one positive sample assuming a within-herd seroprevalence of 30%, 9 sera were collected and analyzed from each farm. Moreover, in 105 farms HEV presence was investigated collecting 10 fecal pools. In order to understand whether consumption of pork products or/and contact with pigs may represent a risk factor, sera were collected from farmers (no.127), general population(no.131) and vegetarian/vegan group (no.114). Abstract results Anti-HEV antibodies were detected in 65.7% (115/175,95% CI:58.2-72.7) of farms, while viral RNA was identified in 24.8% (26/105). Most of the identified strains belonged to HEV3. However, in one farm HEV4 was detected. HEV seroprevalence in humans was significantly different among the 3 groups (p<0.001): farmers showing the greatest prevalence (15.75%,95% CI:9.9-23.3) and general population the lowest (2.3%,95% CI:0.5-6.5). No significant differences were found between general population (omnivorous) and vegetarian/vegan group. Abstract conclusion The survey confirmed a wide spread of HEV in Italian pig herds. The finding of HEV4 can be an issue of concern, considering that it may cause a more severe clinical course in humans. Moreover, our findings reinforce the opinion that HEV infection in industrial countries could be associated with professional activity.