Occult hepatitis B virus infection among Iranian blood donors: a preliminary study.

BACKGROUND: Although serological screening tests for blood-borne hepatitis viruses have effectively reduced the risk of HBV transmission through transfusion of infected blood, there is still a possibility that infected blood units from occult carriers being released into the blood supply. The aim of this study was to determine the prevalence of anti-HBc among Iranian blood donors and evaluate the presence of HBV DNA in HBsAg negative plasma samples. METHODS: In the present study, 5000 HBsAg negative samples were collected from donors in blood transfusion centers in Tehran. All HBsAg negative samples were tested for the presence of anti-HBc antibody and anti-HBs antibody (HBsAb) using ELISA method. Also, all HBsAg negative samples were tested for the presence of HBV DNA by real-time PCR. RESULTS: Four hundred ninety nine (9.98%) out of the 5000 HBsAg negative blood donors were anti-HBc positive. Out of 499 anti-HBc positive samples that were tested for anti-HBs, 394 (78.4 %) were anti-HBs positive, and 275 (62.7%) had an antibody titer greater than 100 IU/mL. HBV DNA was detected in two samples. CONCLUSION: In countries with intermediate rate of HBV infection like Iran, the prevalence of anti-HBc antibody in HBsAg negative blood donors is found to be high. As a result, routine anti-HBc screening of HBsAg-negative blood donors without complementary tests (anti-HBs / HBV-DNA) can limit the number of blood transfusions. Therefore, it might be better to include the detection of HBV DNA along with the routine tests.