Epidemiology of antibody to hepatitis B core antigen screening among blood donors in Eastern Saudi Arabia . Need to replace the test by HBV DNA testing

OBJECTIVE: Prevention of the residual risk of transfusion transmitted hepatitis B virus (HBV) infection is mostly relied on serological screening of blood donors for antibody to hepatitis B core antigen (HBc), to detect donors in window period of HBV infection. This study was carried out to determine the prevalence of anti-HBc antibody among blood donors and its impact on rejection of collected blood units.

METHODS: Blood bank records of all the blood donors who donated blood at blood bank of King Fahad Hospital, Al-Hofuf, Kingdom of Saudi Arabia, during the period of 2000 to 2003 were reviewed. All the collected blood units were screened for hepatitis B surface antigen (HBsAg), anti-HBc, hepatitis C virus (HCV), human immunodeficiency virus (HIV) 1 and 2, HIV p24, human T-cell lymphotropic virus (HTLV) I/II, venereal disease research laboratory (VDRL) and malaria. All the HBsAg negative with anti-HBc positive units were checked for anti-HBsAg antibodies.

RESULTS: Of 26606 blood donors screened, 514 (1.9%) were HBsAg positive, 853 (3.2%) were isolated anti-HBc positive and 2687 (10.1%) were both anti-HBc and anti-HBsAg positive. The blood units, which were anti-HBc and anti-HBsAg positive, were utilized and the isolated anti-HBc positive blood units were rejected. There was a significant (odds ratio of 1.653, 95% confidence interval 1.298-2.105, p<0.0001) decline in anti-HBc positivity during the study period.

CONCLUSION: Isolated anti-HBc positivity as a marker for window period of HBV infection leads to high rejection rate of collected blood units without completely covering the residual risk of HBV transmission by transfusion. Policy for checking the collected blood unit by 3 tests for anti-HBc, anti-HBsAg and HBsAg should be reconsidered in favor of HBV-DNA testing by polymerase chain reaction, to possibly achieve the zero risk goal of transfusion transmitted HBV infection.