Hepatitis E indigenous to economically developed countries: to what extent a zoonosis?
OBJECTIVE
Hepatitis E, a disease transmitted by hepatitis E virus, is increasingly recognized as being indigenous to affluent, temperate-zone countries. Issues pertaining to disease acquisition and hepatitis E virus infection, particularly in Western countries, are reviewed and highlighted.


RESULTS
Clinical hepatitis E in the West, as in Japan, manifests more commonly in older people (>60 years) and in men, but fulminant hepatitis appears less frequent than in Japan. There, specific gastronomic and culinary risk factors associated with disease are being identified, but in the West, data implicating hepatitis E as being foodborne have yet to emerge. While hepatitis E virus subgenomic sequences in Western case patients are found to be closely related to swine hepatitis E virus, a porcine linkage to their infection remains to be established. Weak associations between occupational contact with pigs and risk of infection have been noted. Findings from earlier studies implicating animals that cohabitate with humans as reservoirs, and sewage as vehicles of infection await confirmation.


CONCLUSIONS
Hepatitis E indigenous to developed countries is a distinct clinico-epidemiological entity. Humans, animals, food and the environment contribute and interact to cause human disease, and to sustain hepatitis E virus endemicity and enzooticity.
Teo
Chong Gee
CG
Division of Viral Hepatitis, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. enz0@cdc.gov
D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D019049:Developed Countries; D016751:Hepatitis E / Q000175:diagnosis* / Q000453:epidemiology*; D016752:Hepatitis E virus / Q000235:genetics / Q000502:physiology*; D006801:Humans; D008875:Middle Aged; D012737:Sex Factors; D015047:Zoonoses / Q000453:epidemiology*