High load of hepatitis E viral RNA in pork livers but absence in pork muscle at French slaughterhouses

Pork ham muscle can be contaminated with HEV via blood vessels during viremia and represents a possible source of human contamination via the consumption of dried ham. This study evaluated the prevalence of HEV RNA in pork ham muscles and pork livers at slaughterhouses. Serology was determined on the corresponding serum samples. The apparent individual seroprevalence rate in the 49 pig farms studied was 59% [55.5%-61.4%]. None of the 1134 ham muscles tested was positive for the presence of HEV. HEV prevalence in paired liver samples was 2.8% with a level of contamination of up to 1.46 108 copies/g. Sequences of viral strains isolated from positive livers belonged to genotype 3 and subtypes 3c, 3e, 3f and 3j. Our results confirmed that raw pork liver food products are a source of risk for humans but they also showed that there is a limited risk of human infection by HEV through the consumption of ham muscle.