Hepatitis E infection in humans is a relatively rare form of liver inflammation, caused by a virus. To date, it has been believed that hepatitis E infections in humans chiefly occurred during trips in Asia and Africa. However, recent studies have found that numerous domestic and wild pigs in Europe and Japan carry the hepatitis E virus (HEV). This suggests that the HEV infection is a zoonosis in, at least, some Areas.
The hepatitis E virus (HEV) is a small, non-enveloped, single-strand and positive-sense RNA virus with a genome length of about 7.2 kb and a diameter of ca. 30 – 32 nm and a member of the Hepeviridae family. The virus is highly unstable when exposed to high concentration levels of salt, rapid freezing or thawing processes and heat. We distinguish between four human hepatitis virus E genotypes, which are also referred to according to their main regions of spreading: Mexico, US American, Afro-Asian and Taiwanese genotypes. Genotype III and IV have also been found in swine.
The incidence of HEV genotype 3 (HEV 3) RNA in excrement, serum and organ samples, as well as the high accumulation of anti-HEV antibodies in pigs, has been described in several developed Asian, North American and even European countries. This points to the vast spreading of HEV 3 within the domestic pig and wild boar population.
Hosts, Risks to Humans
To date, there are no detailed scientific studies showing the degree of infection in pigs that could cause an infection of humans under inadequate hygiene conditions. Evidence of the virus in the excrement and organs of swine suggests that the zoonotic potential of hepatitis E in Austrian domestic pigs may be a relevant to public health and can be used to assess a potential risk to occupational risk groups, such as gamekeepers, butchers, veterinarians and even consumers. Furthermore, the virus was also detected in chickens, rabbits, rats, mongooses and deer. There are also indications that the hepatitis E virus may also be found in cattle and sheep.