Serological and molecular biological characteristics of hepatitis B vaccinated donors with asymptomatic chronical infection in Shenzhen

Objective To investigate asymptomatic infection of hepatitis B virus(HBV) among hepatitis B vaccinated donors in Shenzhen, and analyze its serological and molecular characteristics. Methods The HBsAg ELISA positive blood samples of blood donors born after 1992 were collected. HBsAg, anti-HBs, HBeAg, anti-HBe and anti-HBc were further detected by Roche electrochemiluminescence immunoassay (ECL). BCP/PC and S regions were amplified by Nested-PCRs, HBV DNA quantification were adopted by qPCR simultaneously, and the sequences were also analyzed. Results A total of 46 632 blood samples of donors(31 612 males and 15 020 females) from December 2020 to January 2022 collected, and 99 samples with HBsAg ELISA positive were screened out. After tested by ECL, Nested-PCRs, and real-time fluorescence PCR, 61 were confirmed HBsAg positive, with the positive rate at 0.13% (61/46 632), including 49 males (0.16%, 49/31 612) and 12 females (0.08%, 12/15 020). The HBsAg positive rate of males was higher than that of females (P