Hepatitis E infection

Abstract

Hepatitis E — formerly called ‘enterically transmitted non-A non-B hepatitis’ — is transmitted by the faecal-oral route. The Hepatitis E Virus (HEV) is a positive-sense single-stranded RNA virus and has great similarities to the caliciviruses. Virus replication appears to be limited to the hepatocyte. The disease is especially endemic and/or epidemic on the Indian sub-continent. Epidemics are mostly waterborne infections. Also in other ‘developing regions’ outbreaks of HEV infection are observed. In industrialised countries this disease only plays a minor role in hepatitis infections. HEV causes epidemics, endemics and sporadic cases of acute hepatitis. The incubation period for hepatitis E varies from 2–9 weeks. The course of disease is usually mild and self-limiting and resolves within a 2 weeks period. Fulminant cases of infection are rare. HEV infection does not induce chronic courses of hepatitis or liver disease. In clinically apparent cases of infection jaundice, pruritus, clay-coloured faeces and generalised lymphadenopathia may be observed. Fatal infections of fulminant hepatitis E are rare. Pregnant women appear to be exceptionally susceptible to severe disease forms, with an excessive mortality of infected mothers of about 20% in this group. HEV infections appearingly induce mostly life-long immunity to re-infection. To date there is no therapy against HEV infection available. The attempts in generating a vaccine against HEV infections are promising. Improving the socioeconomic situation — including hygienic conditions — is the most effective measure of disease prevention.