Status and serological features of occult hepatitis B virus infection among blood donors in Xuzhou

[Objective] To explore the current status, influencing factors, and serological characteristics of occult hepatitis B virus infection (OBI) among blood donors in Xuzhou, so as to provide data support for improving blood safety screening strategies. [Methods] Blood samples from blood donors from January 2019 to December 2023 in Xuzhou were tested using enzyme-linked immunosorbent assay (ELISA) for serological markers and transaminase levels. Qualified samples were then subjected to nucleic acid testing (NAT). Statistical analysis was performed on the gender, age, education level, and occupation of HBV-infected donors. Logistic regression analysis was used to identify risk factors and epidemiological trends in OBI donors. Chemiluminescence immunoassay was used to quantify the levels of anti-HBs, HBeAg, anti-HBe, and anti-HBc in OBI donors and eligible donors (control group). [Results] Among the 545 292 blood donors, there were 388 OBI donors were identified, with a positive rate of 0.07%. Multivariate logistic regression analysis revealed that male gender, age >45 years, education below college level, and occupation as a farmer were associated risk factors for OBI infection. Among the 388 OBI donors, the predominant serological patterns were anti-HBs and anti-HBc positive (48.71%), anti-HBs, anti-HBe, and anti-HBc positive (16.75%), and anti-HBc alone positive (16.49%). In contrast, the most common patterns among eligible donors were anti-HBs alone positive (46.96%) and serologically negative (26.52%). Anti-HBs levels in OBI donors were significantly lower than those in eligible donors across all patterns (P<0.05). For donors positive for anti-HBc, the distribution of anti-HBs levels in OBI donors was predominantly <100 IU/L, significantly lower than that in eligible donors (P<0.05), while and the proportion of eligible donors with anti-HBs levels >1 000 IU/L was higher than that in OBI donors (P<0.05). [Conclusion] There is a certain proportion of OBI infections among blood donors in Xuzhou, with an overall declining trend. NAT contributes to improved detection rates of HBV infections. The epidemiological distribution of OBI donors in terms of gender, age, education, and occupation differs from that of eligible donors, and there are also differences in serological characteristics between the two groups.