Hepatitis E Virus: The Latest Public Health Scenario

Although hepatitis E virus (HEV) was previously considered a disease restricted to humans, it is now demonstrated to have several animal reservoirs with increasingly complex ecology and molecular diversity. Currently, four HEV genotypes (G1-G4) are being broadly reported. Whilst infection with genotype 1 (G1) and 2 (G2) was only observed in humans, genotypes 3 and 4 were isolated from both humans and animal species. Zoonotic source hypothesis is supported by phylogenetic analysis which demonstrated similarities between gene sequences from patients with autochthonous HEV and animal sources, amongst which swine, wild boar, deer, shell fish and our understanding of the animal host species is still progressing. Animals are responsible for cross-species infections and for environmental maintenance. Human cases have been associated with handling of pigs, with consumption of raw or insufficiently cooked meat and with animal faecal contamination of water and environment. Increasing public health recognition of HEV infection and changes to our understanding of the pathobiology have prompted the current review which aims to summarize research findings in regards to HEV circulation, animal reservoirs, transmission routes and disease burden. These will be integrated into an appreciation of HEV public health significance to highlight control solutions. A special emphasis will be made on the wild animal population in the UK and Europe.