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

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.

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.

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.

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.