e Hepatitis E virus (HEV) infection of zoonotic origin is an emerging concern in industrialized countries. In the past few years, several cases of zoonotic hepatitis E have been identified and the consumption of food products derived from pork liver have been associated with clusters of human cases. More specifically, raw or undercooked pork products have been incriminated. Few data on the effect of heating on HEV inactivation in food products are available. In the present study, the various times and temperatures that are used during industrial processing of pork products were applied to experimentally contaminated food preparations. After treatment, the presence of residual infectious virus particles was investigated using real-time reverse transcription-PCR and an in vivo experimental model in pigs. Results show that heating the food to an internal temperature of 71°C for 20 min is necessary to completely inactivate HEV. These results are very important for determining processing methods to ensure food safety in regard to food-borne hepatitis E. Hepatitis E virus (HEV) infections are responsible for large epidemics of acute viral hepatitis in several developing countries in tropical and subtropical regions. In addition, sporadic cases of hepatitis E have also been reported in the United States, Japan, and Europe. HEV is becoming the first cause of enterically transmitted hepatitis in humans.The disease caused by HEV is typically characterized as selflimiting acute hepatitis with low mortality. However, severe hepatitis has been reported in pregnant women, with up to 20% mortality (23). A significant proportion of healthy individuals in industrialized countries are seropositive for HEV, and a high prevalence of anti-HEV antibodies of more than 20% has been reported in some areas of the United States (18). Anti-HEV antibodies have also been detected in many animal species, and HEV RNA has been isolated from domestic pigs and wild animals (boars, deer, and mongoose). HEV is the only hepatitis virus that infects animals other than primates (22).The virus is a nonenveloped, single-stranded, positive-sense RNA virus, classified in the Hepevirus genus of the Hepeviridae family (11). HEV sequences isolated worldwide can be classified into four major genotypes. Genotypes 1 and 2 have been reported in humans from Asia and Africa and from Mexico. Genotypes 3 and 4 have been identified in both humans and swine in industrialized countries as well as in Asia (23).In regions of endemicity, the main transmission pathway of hepatitis E virus is through consumption of contaminated water or spoiled food. In contrast, in areas of nonendemicity, ingestion of raw or undercooked contaminated deer and boar meat has been associated with sporadic cases of acute hepatitis E in humans (19,26). Furthermore, in several countries, 2 to 11% of pork livers on the market or at slaughterhouses are contaminated by HEV, and some contain infectious virus particles (2,13,25,27). More recently, in France, several cases of hepatitis E were associate...

Hepatitis E virus (HEV) can cause enterically-transmitted hepatitis in humans. The zoonotic nature of Hepatitis E infections has been established in industrialized areas and domestic pigs are considered as the main reservoir. The dynamics of transmission in pig herds therefore needs to be understood to reduce the prevalence of viremic pigs at slaughter and prevent contaminated pig products from entering the food chain. An experimental trial was carried out to study the main characteristics of HEV transmission between orally inoculated pigs and naïve animals. A mathematical model was used to investigate three transmission routes, namely direct contact between pigs and two environmental components to represent within-and between-group oro-fecal transmission. A large inter-individual variability was observed in response to infection with an average latent period lasting 6.9 days (5.8; 7.9) in inoculated animals and an average infectious period of 9.7 days (8.2; 11.2). Our results show that direct transmission alone, with a partial reproduction number of 1.41 (0.21; 3.02), can be considered as a factor of persistence of infection within a population. However, the quantity of virus present in the environment was found to play an essential role in the transmission process strongly influencing the probability of infection with a within pen transmission rate estimated to 2 ⋅ 10− 6g ge− 1d− 1(1 ⋅ 10− 7; 7 ⋅ 10− 6). Between-pen environmental transmission occurred to a lesser extent (transmission rate: 7 ⋅ 10− 8g ge− 1d− 1(5 ⋅ 10− 9; 3 ⋅ 10− 7) but could further generate a within-group process. The combination of these transmission routes could explain the persistence and high prevalence of HEV in pig populations.

In developed countries, most of hepatitis E human cases are of zoonotic origin. Swine is a major hepatitis E virus (HEV) reservoir and foodborne transmissions after pork product consumption have been described. The risk for HEV-containing pig livers at slaughter time is related to the age at infection and to the virus shedding duration. Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) is a virus that impairs the immune response; it is highly prevalent in pig production areas and suspected to influence HEV infection dynamics. The impact of PRRSV on the features of HEV infections was studied through an experimental HEV/PRRSV co-infection of specific-pathogen-free (SPF) pigs. The follow-up of the co-infected animals showed that HEV shedding was delayed by a factor of 1.9 in co-infected pigs compared to HEV-only infected pigs and specific immune response was delayed by a factor of 1.6. HEV shedding was significantly increased with co-infection and dramatically extended (48.6 versus 9.7 days for HEV only). The long-term HEV shedding was significantly correlated with the delayed humoral response in co-infected pigs. Direct transmission rate was estimated to be 4.7 times higher in case of co-infection than in HEV only infected pigs (0.70 and 0.15 per day respectively). HEV infection susceptibility was increased by a factor of 3.3, showing the major impact of PRRSV infection on HEV dynamics. Finally, HEV/PRRSV co-infection – frequently observed in pig herds – may lead to chronic HEV infection which may dramatically increase the risk of pig livers containing HEV at slaughter time.Electronic supplementary materialThe online version of this article (doi:10.1186/s13567-015-0207-y) contains supplementary material, which is available to authorized users.