Prevalence and Molecular Characterization of the Hepatitis E Virus in Retail Pork Products Marketed in Canada

Abstract

Infection with the hepatitis E virus (HEV) is very common worldwide. HEV causes acute viral hepatitis with approximately 20 million cases per year. While HEV genotypes 1 and 2 cause large waterborne and foodborne outbreaks with a significant mortality in developing countries, genotypes 3 and 4 are more prevalent in developed countries with transmission being mostly zoonotic. In North America and Europe, HEV has been increasingly detected in swine, and exposure to pigs and pork products is considered to be the primary source of infection. Therefore we set out to investigate the prevalence of HEV in retail pork products available in Canada, by screening meal-size portions of pork pâtés, raw pork sausages, and raw pork livers. The presence of the HEV genomes was determined by RT-PCR and viral RNA was quantified by digital droplet PCR. Overall, HEV was detected in 47% of the sampled pork pâtés and 10.5% of the sampled raw pork livers, but not in the sampled pork sausages, and sequencing confirmed that all HEV strains belonged to genotype 3. Further phylogenetic analysis revealed that except for one isolate that clusters with subtype 3d, all isolates belong to subtype 3a. Amino acid variations between the isolates were also observed in the sequenced capsid region. In conclusion, the prevalence of HEV in pâtés and raw pork livers observed in this study is in agreement with the current HEV distribution in pork products reported in other developed countries.Electronic supplementary materialThe online version of this article (doi:10.1007/s12560-017-9281-9) contains supplementary material, which is available to authorized users.

Hepatitis E virus infection in Thai blood donors

“…Seroprevalence studies in Thailand further confirmed a link between dietary or occupational exposure to swine and the presence of HEV immunity . The frequency of HEV detection in pork and variety meats sold in Thai markets was similar to or lower than the prevalence found in industrialized countries …”

“…13,14 The frequency of HEV detection in pork and variety meats sold in Thai markets was similar to or lower than the prevalence found in industrialized countries. [15][16][17] In several countries, inadvertent HEV transmission to blood recipients was associated with blood donation from healthy donors who may have acquired zoonotic foodborne HEV infection. 18 Reports of such blood-borne HEV transmission has increased the awareness of potential risks from HEV in donated blood and blood components.…”

Patterns of mutation within an emerging endemic lineage of HEV‐3a

“…Globally, HEV-3a appears to be a well-travelled lineage, with sequences found in farmed pigs in Canada, China, Columbia, France, Indonesia, Japan, South Korea, and Philippines. [28][29][30][31][32][33][34][35] It was also recently identified in German wild boars 36 and was the causative agent of an autochthonous human infection in Europe. 37 It should be noted that nonporcine transmission modes are possible and cannot be ruled out completely.…”

“…All of the National University Hospital (NUH, Singapore) sequences in this study fall within subtype 3a on the phylogenetic tree. Globally, HEV‐3a appears to be a well‐travelled lineage, with sequences found in farmed pigs in Canada, China, Columbia, France, Indonesia, Japan, South Korea, and Philippines . It was also recently identified in German wild boars and was the causative agent of an autochthonous human infection in Europe .…”

Evaluation of High-Pressure Processing in Inactivation of the Hepatitis E Virus

“…The reported prevalence of contaminated pork products varies from less than 1% to more than 50%, depending on the region and the tested commodity (reviewed in (21)). In a previous study conducted by, our laboratory it was observed that 10.5% of sampled raw pork livers, and 47% of the sampled commercial pâté, marketed in Canada, were positive for HEV RNA (25). Because of this high prevalence, efficient strategies to inactivate HEV in ready-to-eat pork products should be considered in order to prevent foodborne HEV infection.…”