Isolated anti-HBc-IgM antibody among blood donors in the semi-arid region of Nigeria.

Laboratory screening for the diagnosis of hepatitis B virus (HBV) infection in blood donors currently consists of testing for hepatitis B surface (HBsAg) antigen alone. The prevalence of isolated anti-HBc-IgM is not yet known in the semi arid region of Nigeria. The major objective of this study was to determine the sero-prevalence of antibody to hepatitis B core antigen (anti-HBc-IgM) and other infectious agent markers; HBsAg, HCV, HIV and Syphilis among blood donors in the North Eastern region of Nigeria. In a cross sectional study from October 2010 to January 2011, 266 blood donors were tested for the infectious disease markers using standard ELISA procedures as contained in the manufacturer's standard operating procedures. The prevalence of various infectious markers obtained were as follows: HBsAg (8.6%); anti-HCV (1.5%); HIV (2.6%) and anti-HBc-IgM(18.4%). There was a zero percent prevalence of Syphilis in this donor population. The proportion of isolated anti- HBc-IgM antibody obtained was 18.1%. Performance indices for HBsAg were as follows: Sensitivity (10.2%), specificity (91.7%), positive predictive value (PPV) (21.7%), Negative predictive value (81.9%), and efficiency (76.7%). The prevalence of anti-HBc- IgM antibody was higher among first time blood donors (21.4%), and in some ethnic groups. There is a high prevalence of isolated anti-HBc-IgM antibody among blood donors in Maiduguri. The sensitivity of HBsAg was found to be very low and as such many recent HBV infections may be missed during pre-transfusion screening. The use of anti-HBc-IgM screening as a mandatory pre-transfusion screening test is hereby advocated.