ABSTRACT
<p><b>OBJECTIVE</b>To understand the prevalence of sub-clinical infection of hepatitis E virus (HEV) among blood donors.</p><p><b>METHODS</b>A cluster sampling strategy was used to sample all blood donors from July to August in 2002 in Beijing. Their blood was tested for IgM and IgG antibody against HEV.</p><p><b>RESULTS</b>The prevalence of anti-HEV IgM among blood donors in Beijing was 1.74%. The rate of abnormal alanine aminotransferase (ALT) in anti-HEV IgM positive donors is significantly higher than anti-HEV IgM negative donors. Among all ALT abnormal donors, 2.68% can be associated with HEV sub-clinical infection. The percentage is similar with HBV but higher than HCV.</p><p><b>CONCLUSION</b>There are sub-clinical infection of HEV among blood donors, which is one of the cause of abnormal ALT in the donors.</p>