Occult hepatitis B virus infection among Egyptian blood donors

AIM:To identify blood donors with occult hepatitis B virus(HBV) infection(OBI) to promote safe blood donation.METHODS:Descriptive cross sectional study was conducted on 3167 blood donors negative for hepatitis B surface antigen(HBsAg),hepatitis C antibody(HCV Ab) and human immunodeficiency virus Ab.They were subjected to the detection of alanine aminotransferase(ALT) and aspartate transaminase(AST) and screening for anti-HBV core antibodies(total) by two different techniques;[Monoliza antibodies to hepatitis B core(Anti-HBc) Plus-Bio-Rad] and(ARC-HBc total-ABBOT).Positive samples were subjected to quantitative detection of antibodies to hepatitis B surface(anti-HBs)(ETI-AB-AUK-3,Dia Sorin-Italy).Serum anti-HBs titers > 10 IU/L was considered positive.Quantitative HBV DNA by real time polymerase chain reaction(PCR)(QIAGEN-Germany) with 3.8 IU/mL detection limit was estimated for blood units with negative serum anti-HBs and also for 32 whose anti-HBs serum titers were > 1000 IU/L.Also,265 recipients were included,34 of whom were followed up for 3-6 mo.Recipients were investigated for ALT and AST,HBV serological markers:HBsAg(ETI-MAK-4,Dia Sorin-Italy),anti-HBc,quantitative detection of anti-HBs and HBV-DNA.RESULTS:525/3167(16.6%) of blood units were positive for total anti-HBc,64% of those were antiHBs positive.Confirmation by ARCHITECT anti-HBc assay were carried out for 498/525 anti-HBc positive samples,where 451(90.6%) confirmed positive.Reactivity for anti-HBc was considered confirmed only if two positive results were obtained for each sample,giving an overall prevalence of 451/3167(14.2%) for total anti-HBc.HBV DNA was quantified by real time PCR in 52/303(17.2%) of anti-HBc positive blood donors(viral load range:5 to 3.5 x 105 IU/mL) with a median of 200 IU/mL(mean:1.8 x 104 ± 5.1 x 104 IU/mL).AntiHBc was the only marker in 68.6% of donors.Univariate and multivariate logistic analysis for identifying risk factors associated with anti-HBc and HBV-DNA positivity among blood donors showed that age above thirty and marriage were the most significant risk factors for prediction of anti-HBc positivity with AOR 1.8(1.4-2.4) and 1.4(1.0-1.9) respectively.Other risk factors as gender,history of blood transfusion,diabetes mellitus,frequent injections,tattooing,previous surgery,hospitalization,Bilharziasis or positive family history of HBV or HCV infections were not found to be associated with positive anti-HBc antibodies.Among anti-HBc positive blood donor