Infection of Pigs with Avian Hepatitis E Virus (HEV)
Iowa State University Animal Industry Report 2005. It is now known that HEV can cross-species barriers. In the present study, we used a pig model to determine if HEV from chickens (avian HEV) or rats (rat HEV) was infectious to pigs. Thirty six, SPF pigs were randomly separated into 4 groups of 9 pigs each. Group 1 served as the sham-inoculated group. Group 2 was inoculated with rat HEV. Group 3 was inoculated with avian HEV. In the rat and avian HEV groups, 6 pigs were inoculated with the corresponding virus and 3 pigs remained uninoculated and served as contact controls. Group 4 was inoculated with the prototype swine HEV. Necropsy of 3 pigs from each group was performed on 7, 21, and 35 days postinoculation (dpi). In the rat and avian HEV groups, 2 inoculated and 1 contact control pigs were necropsied at each time point. Liver and bile from sham-inoculated pigs were negative for HEV throughout the study. Pigs in the sham and rat HEV group remained noninfected. Pigs inoculated with avian HEV and those inoculated with the swine HEV became viremic and shed HEV in feces. Both the avian and swine HEV infected pigs had mild-tomoderate lymphoplasmacytic hepatitis. The findings indicate that avian HEV is transmissible to pigs. This may open new areas of study in the epidemiology of HEV. Pigs may be an excellent model for comparative molecular and pathogenetic studies of different HEV strains.