Hepatitis E Virus in Pork and Variety Meats Sold in Fresh Markets

Abstract

Swine is an economically important livestock, yet pork consumption and close contact with pigs are associated with the risk of hepatitis E virus (HEV) infection. Limited data on the prevalence of HEV in Southeast Asia have mainly examined farm animals. To investigate the potential zoonotic transmission of HEV from dietary consumption of pork and variety meats (i.e., offal or organ meats), we obtained 1090 liver, 559 pork meat, and 556 intestine samples from fresh markets in the Bangkok metropolitan area between November 2014 and February 2015. The presence of HEV was assessed using reverse-transcription polymerase chain reaction. Concurrently, 720 bile and 553 fecal samples from a slaughterhouse were also examined. Overall, HEV RNA was found in 0.23 % of the market samples and 3.93 % of the slaughterhouse samples. Fecal and bile samples were more likely to test positive compared to liver, pork, and intestine samples (p < 0.001). Phylogenetic analysis showed that all HEV sequences obtained in this study formed a cluster closely related to genotype 3f. Pork and variety meats derived from pigs are commonly sold in fresh markets throughout Southeast Asia. Here, a relatively low HEV prevalence from pork and variety meats sold in Bangkok was found. Additional studies will be required to further assess potential dietary transmission of HEV elsewhere in the region.

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

“…Subtypes are no longer limited to their regions of origin, such as the discovery of both major HEV-3 groups in UK even though only G3efg has been found in indigenous pigs, 26 as well as the discovery of HEV-3f viruses in Bangkok retail pork in supermarkets. 27 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.…”

“…Increasing efforts in HEV surveillance has revealed a complex picture of the global circulation of HEV‐3 subtypes, with no clear regional demarcations. Subtypes are no longer limited to their regions of origin, such as the discovery of both major HEV‐3 groups in UK even though only G3efg has been found in indigenous pigs, as well as the discovery of HEV‐3f viruses in Bangkok retail pork in supermarkets …”

High circulation of Hepatitis E virus in pigs and professionals exposed to pigs in Laos

“…In contrast to others (Colson et al, ; Renou, Afonso, & Pavio, ), we did not find a significant association between consumption of raw meat and HEV exposure. Also in Thailand, the low prevalence of HEV RNA in pig products suggested that foodborne infections play a minor role for HEV epidemiology (Intharasongkroh et al, ).…”