Summary
Hepatitis E is an infectious viral disease with clinical and morphological features of acute hepatitis. The aetiological agent is the hepatitis E virus (HEV). The disease represents an important public health problem in developing countries where it is frequently epidemic and is primarily transmitted by the faecal-oral route. In recent years, a number of sporadic cases have also been described in industrialised countries, Italy included. Swine HEV was first identified in 1997 and is now considered a ubiquitous virus. Human and swine strains from the same region have been shown to have a high level of nucleotide homology and, in experimental infections, the possibility of cross-species transmission of swine strains to humans and of human strains to non-human primates has been demonstrated. Furthermore, some seroepidemiological studies have demonstrated that people working in contact with swine have a higher risk of infection than regular blood donors. Recently, cases of HEV hepatitis in Japan were directly associated with the ingestion of uncooked meat from pigs, wild boar or deer and today the disease is considered an emerging zoonosis. The authors summarise current virological and epidemiological knowledge on HEV infections so as to stimulate interest in a virus that has not received much attention in veterinary medicine, but that could become an important zoonotic agent.

Keywords
Animal diseases, Hepatitis E, Pigs, Public heath, Viruses, Zoonoses.