Sorveglianza dell'infezione da virus dell'epatite E (HEV) in Italia: from farm to table

Hepatitis E is an acute disease of humans, caused by a positive ss RNA virus, Hepatitis E virus (HEV). Several evidences, including genetic similarity between human and swine HEV strains from the same area, suggest zoonotic transmission. From 2011 to 2013, we conducted a survey for HEV in 19 swine farms and 2 slaughterhouses in different Italian regions, collecting 343 feces and 70 bile samples. Moreover, a retrospective study was conducted on 78 animals housed in 3 farms locate in Northern Italy and collected in 2000. Overall HEV was detected in 24.5% and 19.2% of fecal samples collected in 2011-2013 and in 2000, respectively. On the contrary, none of bile samples was positive. Furthermore, the genome of one SwHEV strain was completely sequenced to evaluate possible correlation with swine and human HEV strains. We investigated presence of HEV in a swine food chain from farm to finish products, enrolling a big Italian factory which trades pig meat across the country. Thirty-four feces, liver and muscle samples were collected in a slaughterhouse from 34 clinically healthy pigs, aged 6-7 month old. At slaughterhouse 14 fecal samples and 2 liver, resulted positive for HEV. Moreover, none of the sausages (129) collected at processing and point of sale were positive. We have also evaluated the presence of HEV and fecal cross-contamination in pork liver sausages bought at a grocery in Italy. The genome of HEV was detected in both raw (22.2%) and dry (4.3%) liver sausages, but the viability of the virus was not demonstrated. Finally, several cell lines were inoculated with HEV-positive fecal and pork liver samples to attempt HEV replication but virus growth was not established.