Inactivation of infectious hepatitis E virus present in commercial pig livers sold in local grocery stores in the United States

Int J Food Microbiol. 2008 Mar 31;123(1-2):32-7. doi: 10.1016/j.ijfoodmicro.2007.11.068. Epub 2007 Dec 4.


Hepatitis E virus (HEV) is a zoonotic pathogen and pigs are a known reservoir. Recently we showed that approximately 11% of commercial pig livers sold in local U.S. grocery stores for food consumptions are contaminated by infectious HEV. In this study, a swine bioassay was used to determine if the infectious HEV in contaminated commercial pig livers could be inactivated by traditional cooking methods. Group 1 pigs (n=5) were each inoculated intravenously (i.v.) with a HEV-negative liver homogenate as negative controls, group 2 pigs (n=5) were each inoculated i.v. with a pool of two HEV-positive pig liver homogenates as positive controls, groups 3, 4 and 5 pigs (n=5, each group) were each inoculated i.v. with a pool of homogenates of two HEV-positive livers incubated at 56 degrees C for 1 h, stir-fried at 191 degrees C (internal temperature of 71 degrees C) for 5 min or boiled in water for 5 min, respectively. As expected, the group 2 positive control pigs all became infected whereas the group 1 negative control pigs remained negative. Four of the five pigs inoculated with HEV-positive liver homogenates incubated at 56 degrees C for 1 h also became infected. However, pigs in groups 4 and 5 did not become infected. The results indicated that HEV in contaminated commercial pig livers can be effectively inactivated if cooked properly, although incubation at 56 degrees C for 1 h cannot inactivate the virus. Thus, to reduce the risk of food-borne HEV transmission, pig livers must be thoroughly cooked.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biological Assay
  • Consumer Product Safety
  • Disease Reservoirs / veterinary
  • Disease Reservoirs / virology
  • Food Contamination / analysis*
  • Food Handling / methods*
  • Hepatitis E / transmission*
  • Hepatitis E / veterinary
  • Hepatitis E virus / genetics
  • Hepatitis E virus / isolation & purification*
  • Hepatitis E virus / pathogenicity
  • Humans
  • Liver / virology*
  • RNA, Viral / chemistry
  • RNA, Viral / genetics
  • Random Allocation
  • Reverse Transcriptase Polymerase Chain Reaction
  • Swine
  • United States


  • RNA, Viral