Evidence of Hepatitis E Virus (HEV) infection in human and pigs in Sardinia, Italy


Introduction. The aim of this study was to determine the seroprevalence of anti-HEV antibodies in humans sera and to study HEV prevalence in swine from different Sardinian farms, testing viral HEV-RNA in bile samples. Methods. In the first six months of 2008, 532 subjects of whom 402 blood donors and 130 workers at zoonotic risk, were enrolled. Anti-HEV were determined with an enzyme linked immunosorbent assay (ELISA). In positive subjects, RNA was extracted and tested by RT-Nested-PCR. From July 2006 to March 2007, 95 bile samples were collected from randomly selected pigs. RNA was extracted from 250 ?l of bile and tested by RT-Nested-PCR. Results. The overall prevalence of anti-HEV antibodies was 4.3%; 5.0% among blood donors and 2.3% among workers at zoonotic risk, with no statistically significant differences between sex, age classes and occupation. The search for HEV-RNA in the subjects positive for antibodies, gave negative results. HEV genome was detected in 6 of the 95 swine bile samples tested. Sequences were clustered within the genotype 3 and are edited on GenBank under accession number: from FJ850960 to FJ850962 and from FJ883000 to FJ883002. Discussion. The overall prevalence of anti-HEV shows that the virus circulates without giving origin to cases of acute hepatitis. The low prevalence value found in workers at zoonotic risk do not apparently support the hypothesis of professional risk. In this study, HEV-RNA was isolated from pigs in Sardinia for the first time confirming the role of swine as HEV reservoir and the possibility of virus transmission to humans.