Serological Patterns and Molecular Characterization of Occult Hepatitis B Virus Infection among Blood Donors

Background: hepatitis b infections, characterized by the presence of a viral genome without detectable hepatitis b surface antigen (hbsag; occult hepatitis b infection [obi]), have been reported recently. objectives: we performed serological and molecular characterization of obi among blood donors at jiangsu province blood center during years 2013 and 2014. methods: all donor samples were routinely screened by double enzyme-linked immunosorbent assay (elisa) for hepatitis c virus (hcv), hepatitis b virus (hbv), human immunodeficiency virus (hiv), treponema pallidum (tp), and alanine aminotransferase (alt). single-reactive, nonreactive, and alt-elevated samples were pooled or resolved by nucleic acid testing (nat). seromarkers were examined in hbsag-/dna+ samples. after 1 to 12 months of follow up, seromarkers were screened again to verify obi samples. results: we studied 157119 samples from blood donors. a total of 154397 elisa nonreactive donor samples were identified, and hbv dna was detected in 81 samples; no samples were positive for hiv or hcv rna. hepatitis b virus viral loads in most donors were less than 20 - 200 iu/ml. there was only one hbsag-positive sample. eighty hbsag-/dna+ samples were evaluated further. of these samples, 85% (68/80) were reactive for anti-hbc and 36.2% (29/800) were reactive for anti-hbc and anti-hbs; 11.3% (9/80) did not have any detectable serological markers. twenty-nine donors were followed up. one was hbsag elisa positive, and of six seronegative donors, all had anti-hbc and anti-hbs, but were negative for dna. samples were hbv genotypes b, c and d. mutations in the s region of hbv dna included s114t, g119r, p120s, t125m, c139y, t140i, c147w, t148a, a159v/g, e164d, v168a, and r169c. conclusions: overall, we found that obi was rare, but that the prevalence of obi was slightly higher in jiangsu than in other areas of china.