ABSTRACT
The incidence of post-transfusion hepatitis has been reduced greatly by screening blood donors for hepatitis B surface antigen (HBsAg). However, hepatitis B virus infection still accounts for a certain number of cases of post-transfusion hepatitis. The purpose of this study was to detect HBV DNA in the HBsAg negative blood samples by using nested PCR with two primer pairs specific to core region. Two hundreds blood samples from HBsAg negative donors, and 14 samples from HBsAg positive donors were provided by the blood bank of Ramathibodi Hospital. The results showed that HBV DNA was detected in all 14 HBsAg positive blood samples and in 7 (3.5%) of 200 HBsAg negative blood samples. This study showed that the absence of HBsAg in otherwise apparently healthy individuals may not be enough to ensure lack of circulating HBV. The more sensitive ELISA technique is still in need. Otherwise, the safety of blood transfusion can be enhanced by careful selection of blood donors and careful consideration of risks and benefit of the patients who need blood transfusions.