Prevalence of occult HBV infection among blood donors in Huzhou City，Zhejiang Province

Objective To explore the prevalence and characteristics of occult hepatitis B virus infection （OBI） among blood donors in Huzhou region.

Methods A total of 31 348 blood donors collected from October 2018 to February 2020 were selected for detecting HBV infection markers by serological and nucleic acid detection techniques. According to the detection results， 27 cases of HBsAg double negative （two kinds of reagent detection）， nucleic acid amplification technology （NAT） positive samples were identified as the occult HBV infection group （OBI group）； 25 cases of HBsAg double positive （two kinds of reagent detection）， NAT positive samples were identified as dominant HBV infection group， respectively. HBV nucleic acid quantitative detection， serum hepatitis B three line markers， liver function markers detection， and the results of the two groups were compared and analyzed.

Results There were 31 034 HBsAg negative blood donors， 27 of whom were HBV-DNA positive， and the prevalence of OBI was 0.87 ‰. Six kinds of serology were found in 27 OBI patients， among which 25 cases （92.6%） were HBcAb， 17 cases （63.0%） were HBsAb， 17 cases （63.0%） were HBeAb， 15 cases （55.6%） were HBcAb and HBsAb， and 14 cases （51.9%） were HBcAb and HBeAb. There was no significant difference in gender， HBcAb positive rate， TBI， AST and ALT between the two groups （P>0.05）. There were significant differences in age and HBsAb level （χ²=1.201， P<0.001； t=28.336， P<0.001）， and the average viral load was （25.86±19.68） IU/mL， which was significantly lower than the average viral load of the control group （3 254.65±535.98）IU/mL（t=32.412， P<0.01）.

Conclusion There is a certain prevalence of OBI in blood donors in Huzhou area. The main kinds of serology are HBcAb and HBsAb. Serological detection combined with nucleic acid detection can ensure the safety of blood transfusion and reduce the risk of blood borne diseases.