Our results suggest including anti-HBc as an additional screening test for blood donors in Syria to reduce the risk of HBV transmission. As the most cost-effective measure, anti-HBc-positive donors should be tested quantitatively for anti-HBs and only donors with no or low (<100 IU L(-1) ) anti-HBs should be deferred.

Introduction: We aimed to evaluate the prevalence of "anti-HBc alone" among Syrian blood donors, highlighting the possibility of representing occult HBV infection. Methodology: Sera of 3,896 healthy blood donors were tested for both HBsAg and anti-HBc. HBsAg-negative, anti-HBc-positive samples were further tested for the antibodies to HBsAg (anti-HBs), and "anti-HBc alone" sera were tested for HBV DNA. Results: Of 3,830 HBsAg-negative donors, 63 were "anti-HBc alone" donors, five of whom were HBV DNA positive. Conclusions: Greater consideration should be given to the "anti-HBc alone" serological profile in blood screening, premarital testing, organ transplantation tests, and other HBV transmission-related procedures in Syria.