Hepatitis E virus (HEV) is an important public health problem and responsible for both acute and chronic viral hepatitis. The HEV transmission usually occurs through the fecal-oral route, and public health implications of its water-borne and food-borne transmissions along with environmental contamination raise high concerns towards its zoonosis. Apart from affecting developing countries, this virus is causing a rising number of cases in the developed countries. The spread of HEV particles to the environment can pollute surface waters, which could be an HEV infection source for humans and animals. HEV has also been identified in urban sewage samples in various countries. HEV virus quite frequently infects the European community and some animal species and identification of virus in polluted animal products suggest the circulation of HEV from water to food chain. Several studies indicating high seroprevalence and circulation of HEV in pigs as well as in environmental samples warrants to investigate the role of trade in carrier pigs, elucidate HEV virulence maintenance in the environment and meat supply chain to throw light on the possible sources of infection in humans and the degree of occupational risk, and zoonosis. The purpose of this review is to discuss the HEV infections and associated risk factors with an emphasis on pigs, presence in environment, food-borne, water-borne, and zoonotic transmissions.
