Hepatitis E virus -- an update.

Hepatitis E virus (HEV) is the principal cause of enterically-transmitted, non-A, non-B hepatitis and has been associated with excess mortality in pregnant women infected during epidemics. Molecular cloning of the viral genome led to the development of diagnostic tests, including enzyme immunoassays for antibody and RT-PCR for viral RNA. Candidate vaccines have not yet reached clinical trials. The virus resembles caliciviruses, with a positive sense RNA genome encoding three open reading frames. The geographical distribution of the virus, which may infect domestic animals as well as humans, may be wider than thought originally.