Prevalence of Hepatitis E Virus in Wild Boar (Sus Scrofa) in Latium Region

Objectives Hepatitis E is a leading cause of acute viral hepatitis in tropical and subtropical countries due to a small RNA virus, the Hepatitis E virus (HEV). In recent years, an increasing number of autochthonous human infections have been reported in industrialized countries that involve HEV genotypes 3 and 4. Genotype 3 is the main HEV type circulating in swine, and is also reported in sporadic cases of hepatitis E in humans worldwide. To date only one serotype has been described Although, swine HEV strains have been detected in pig herds in many European countries, only few information is presently available about the circulation and the prevalence of HEV in wild boars in Italy. The wild boar (Sus scrofa) is widely diffuse in Appennino mountains in central and southern Italy. This wild animal can leave its natural habitat to come into contact with domestic animals. For this reason, it is a potential source of infectious diseases not only for animals (wild and domestic) but also for humans. Methods In this study, we investigated the presence of HEV in a wild boar population in Italy. The prevalence of HEV infection was determined in 228 wild boar (Sus scrofa) harvested during the 2010–2011 hunting season in Latium region, central Italy. A serum-survey to detect anti-HEV antibodies was performed using a commercial ELISA assay previously validated for use in wild boar. Mean seroprevalence in the studied animal group was 64%. Bile, liver and faeces were also collected, and HEV RNA was detected by nested reverse transcription-polymerase chain reaction, amplifying a fragment of the ORF27. Positive DNA PCR products, were excised from agarose gels and purified using the QIAquick Gel Extraction Kit following manufacturer's instructions. Results Mean seroprevalence in the studied animal group was 64%. Fifteen out of 35 tested wild boar samples (42.8 %) were positive for HEV RNA in at least one sample. Genetic characterization of wild boar strains identified was performed by sequencing and database alignment. Unfortunately, it was not possible to sequence all samples due to the low amount of DNA. Phylogenetic analysis on the nucleotide sequences from 6 positive PCR products indicated that all strains belonged to genotype 3. Conclusion Wild boars can be carriers of pathogens such as hepatitis E. The handling and preparation of domestic raw wild boar meat before to cooking treatment, can lead to cross contamination of other foods of breeding domestic pigs outdoors, in areas in close contact with wild boar, may increase the risk of transmission of these pathogens between the two groups.