Distribution and Propagation of Hepatitis E Virus in Experimentally Infected Swine

HEV infections in human and pigs have been reported in many countries; however, the precise distribution and multiplication of this virus in the host remains poorly understood. In this study, we examined the distribution and multiplication of HEV genotype 3 in two piglets at the early phase of intravenous infection, and also examined the virus distribution in a naturally infected pig. We developed real-time RT-PCR to determine copy numbers of the HEV genome in the sera, feces and organs. HEV-RNA was detected in serum from a pig transiently for 7 days post-inoculation (dpi). The HEV copy numbers in the feces appearing 7 dpi were increased to 3.4x106 copies/g at 14 dpi. In contrast, the higher copy numbers of HEV were widely distributed in the tissue organs from naturally HEV-infected pig. The study showed that intravenously inoculated HEV was distributed in several restricted tissues, such as in the liver and intestine.