Hepatitis E: a curious zoonosis.

Hepatitis E virus (HEV) is responsible for large waterborne epidemics of acute hepatitis in endemic regions and for sporadic autochthonous cases in non endemic regions. Although the water vector has been thoroughly documented in endemic regions, very little is known about the modes of contamination occurring in non endemic regions. Unlike the other hepatitis viruses, HEV has an animal reservoir. Several lines of evidence, such as the results of phylogenic analysis and studies on direct contamination via infected food products, have suggested that some cases of animal to human transmission occur. However, all the possible sources of human contamination in non endemic areas have not yet been defined, and this point needs to be investigated. The high genetic variability of HEV, which might be an important factor, involved in zoonotic contamination processes, also needs a surveillance plan.