[Hepatitis E--a new zoonotic disease in Germany?].

Hepatitis E virus (HEV) is the most frequent pathogen of a fecal-oral transmitted hepatitis in humans in many developing countries. It is endemic in the Middle East, in India, in Southeast Asia, central Asia as well as in Central and South America. It can be predominantly found in young adults. The mortality rate comes up to 2% whereas in pregnant women death rate can reach about 25%. Until a few years ago, acute hepatitis E was thought to be rare in industrialized countries: most cases were found in persons with a corresponding travel history. However, after improvement of the diagnostic possibilities, an increasing number of autochthonous cases with acute hepatitis E have become evident. Besides, a relatively high seroprevalence of 1 to 5% in the population in industrialized countries is noticeable which is converse to the only sporadic occurrence of acute hepatitis E. As a reason for this an animal reservoir for HEV is being discussed. The first HEV recovering from an animal succeeded in 1997 from a pig in the USA. Genetic typing showed close relationship between the porcine HEVand human HEV types. This confirmed the suspicion on a zoonotic potential of HEV. Transmission experiments revealed that non-human primates were sensitive to the porcine HEV and pigs could be infected with human HEV. Besides, occupational groups with close contact to pigs evidently have an increased risk for HEV infections. In addition, reports of acute hepatitis E after the consumption of undercooked wild boar meat supported the zoonotic potential of HEV. In the domestic pig and wild boar population in several European countries the virus is ubiquitous. In Germany a high percentage of the wild boars was proven to be infected with HEV. In contrast, studies of HEV circulation in domestic pigs are still pending.