Molecular detection and phylogenetic analysis of hepatitis E virus strains circulating in wild boars in south-central Italy.

Hepatitis E virus (HEV) is a zoonotic pathogen with a worldwide distribution, and infects several mammalian species, including pigs and wild boars, which are recognized as its natural reservoirs. The virus causes a usually self-limiting liver disease with a mortality rate generally below 1%, although mortality rates of 15%-25% have been recorded in pregnant woman. Chronic infections can also occur. The prevalence of HEV has been extensively studied in wild boars and pigs in northern Italy, where intensive pig herds are predominantly located. In contrast, few data have been collected in south-central Italy, where small pig herds are surrounded by large regional parks populated with heterogeneous wild fauna. In this study, 291 liver samples from wild boars caught in south-central Italy were analysed with the molecular detection of viral RNA. Our results confirm the circulation of HEV in these animals, with a mean prevalence of 13.7% (40 of 291). A nucleotide sequence analysis showed that the HEV strains were highly conserved within the same geographic areas. The wild boar HEV strains belonged to the HEV-3c subtype, which is frequently described in wild boars, and to an uncommon undefined subtype (HEV-3j-like).The viral prevalence detected is concerning because it could represent a potential risk to hunters, meat workers and consumers of wild boar liver and derivative products. The hypothesized inter-species transmission of HEV to pigs and the possibility that the virus maintains its virulence in the environment and the meat chain also present potential risks to human health, and warrant further investigations in the near future.

Retrospective Study Evaluating Seroprevalence of Hepatitis E Virus in Blood Donors and in Swine Veterinarians in Italy (2004).

Hepatitis E is an emerging viral disease in developed countries, with sporadic cases occasionally linked to the consumption of raw or undercooked pork, wild boar or deer meat. Cases due to transfusion or transplantation have also been reported. In developed countries, hepatitis E is considered a zoonosis and pig is the main reservoir. In the last few years, several studies conducted in Europe reported variable seroprevalence rates among the general population, ranging between 0.26% and 52.5%. A higher seroprevalence was described among workers who come in contact with pigs. The aim of this retrospective study was to evaluate the seroprevalence of anti-HEV IgG and IgM antibodies in blood donors (170) and in pig veterinarians (83). Archival sera were collected in Italy in 2004. The observed seroprevalence was 9.64% and 8.82% in veterinarians and blood donors, respectively. Overall, only three sera from blood donors were positive for IgM, but no HEV-RNA was detected.

Serological survey of hepatitis E virus infection in farmed and pet rabbits in Italy.

The recent identification in rabbits of hepatitis E viruses (HEV) related to viruses infecting humans raises the question of the role of this species as possible HEV reservoir. A serological survey on rabbit HEV infection was conducted in Italy during 2013-2014, including both farmed and pet rabbits. We found an anti-HEV antibody seroprevalence of 3.40 % in 206 farmed rabbits (collected on 7 farms) and 6.56 % in 122 pets. RNA was extracted from IgG-positive sera and analyzed by HEV-specific real-time RT-PCR. None of the samples were positive, confirming that no viremia was present in the presence of IgG. Only one serum sample from a farmed rabbit was positive for IgM, but no HEV RNA was detected in it. Pet rabbit feces were also tested for HEV RNA, with negative results. This finding suggests that HEV is circulating in rabbits in Italy.