Animal infections: The hypothesis that HEV infection is a zoonosis was supported with accumulating evidence. Swine HEV and later an avian HEV have been identified and sequenced separately in 1997 and 2001. HEV infection induces production of anti-HEV antibodies and includes viremia and feces excretion of HEV. Consumption of uncooked deer meat infected with HEV has led to acute hepatitis E in humans in Japan. The current estimation is that over 90% of the pigs among pig farms in UK, Holland, the US ,etc is infected with HEV
HEV in blood donors: While HEV transmission usually occurs by eating and drinking contaminated food and water, blood transfusion is another route of infection.In a study conducted with 44,816 donor samples were collected in China between 2002 to 2008, the HEV seroprevalences in blood donors ranged from 29.9% to 41.7%. The rate of acute HEV infection was 0.43% to 1.51%. The viremia rates among the donors in 6 different regions of China ranged from 0.02% to 0.14%. These results also showed a high prevalence of viremia among anti-HEV IgM-positive samples. A total of 7.14% (30/420) of anti-HEV IgM-positive samples were RNA positive, but none of the IgM-negative samples were HEV RNA positive.
Wantai HEV diagnostics:
Our approach in developing of HEV immunoassays relies on optimizations in the detection techniques and improvements in the quality of the raw materials. We have developed a recombinant capsid antigen (E2), expressed from the highly conserved region of ORF2 of the HEV. This antigen expresses important conformation antigenic epitopes of the native virus and shows extremely high reactivity to HEV specific antibodies. With this antigen, we have significantly improved the sensitivity and specificity of our HEV assays.