[Hepatitis E virus: current status]

In areas with tropical or subtropical climate and poor sanitary conditions, hepatitis E is the major cause of enterically transmitted non-A, non-B hepatitis, and is responsible for both water-borne outbreaks and sporadic cases of acute hepatitis. The causative agent is the hepatitis E virus (HEV), a non-enveloped, single-stranded, positive-sense RNA molecule of an approximately 7.2 kb length. Recently, HEV strains have been isolated in swine in industrialized countries. In addition, cases of acute hepatitis due to novel HEV variants have been reported in humans without recognized risk factors for hepatitis E in Europe, Japan and the US. Some of the novel strains were found to be closely related to swine HEV isolates from the same area, suggesting that hepatitis E is a zoonotic disease. Thus hepatitis E is becoming a concern in countries where HEV is not, traditionally, believed to be endemic. This review summarizes the current knowledge of the biology, structure and transmission of the virus as well as the diagnosis of the infection. We also analyze the present status in areas with a low incidence of acute hepatitis E and the role of animals as potencial vectors of the virus.