Description
Hepatitis E virus (HEV) is a non-enveloped, single- stranded
RNA virus identified in 1990. Infection with HEV induces
acute or sub-clinical liver diseases similar to hepatitis A. HEV
infections, endemic and frequently epidemic in developing
countries, is seen also in developed countries in a sporadic
form with or without a history of traveling to endemic area.
The overall case-fatality is 0.5~3%, and much higher
(15~25%) among pregnant women. A hypothesis that HEV
infection is a zoonosis was presented in 1995. Then a swine
HEV and later an avian HEV were identified and sequenced
separately in 1997 and 2001. Since then, HEV infection
include anti-HEV, viremia and feces excretion of HEV was
seen in a wide variety of animals, i.e., swine, rodents, wild
monkeys, deer, cow, goats, dogs and chicken in both the
developing and developed countries. A direct testimony was
reported that the consumption of uncooked dear meat
infected with HEV led to acute hepatitis E in human. And HEV
genome sequences can be detected in pork livers available in
the supermarkets in Japan.
With the discovery of conformational epitopes in HEV, HEV
serology was further explored and understood. The
phenomenon of long-lasting and protective antibodies to HEV
was observed which greatly enhance the understanding to the
diagnosis, epidemiology, zoonosis-related studies and
vaccine development.
