Hepatitis E Virus

Abstract

Hepatitis E virus (HEV) is taxonomically classified within Hepeviridae family and Orthohepevirus genus. Genotypes HEV-1 and HEV-2 infect human, while genotypes HEV-3 and HEV-4 are zoonotic viruses that infect humans, domestic pigs and other animal species (e.g. wild boar, deer). The main route of trans-species transmission is the direct contact with infected animals, as well as via the consumption of HEV-contaminated food products or via the faecal–oral route through drinking of contaminated water. HEV-3 has been detected in pigs around the world (South and North America, Europe, Africa, Asia, and Oceania). HEV-4 has mainly reported in domestic pigs and humans in Asia. Domestic pigs, wild boar, and various species of deer reported to play important role in zoonotic transmission of HEV-3 and HEV-4 from animals to humans. The most important reservoirs of the HEV genotypes are domestic pigs and the most HEV infections in humans are foodborne due mainly to consumption of undercooked meat or meat products (e.g. sausages). The main route of natural HEV transmission in pigs is via the faecal–oral. However, the HEV infection in pig is usually asymptomatic, with low impact on health status. Future studies focus on preventive measures to eliminate the appearance and persistence of HEV in pig farms (including biosecurity and vaccination) are required. Moreover, more studies are needed to investigate deeply the role of wildlife in the epidemiology of HEV infection.