【Objective】 To investigate HIV-1 subtype distribution and trend among Dalian blood donors between 2011 and 2020, in order to provide information to improve blood safety and HIV prevention. 【Methods】 HIV RNA was purified from plasma samples of Dalian blood donors with confirmed HIV infection, which were collected between 2011 and 2020. The HIV pol gene was amplified and sequenced. HIV-1 subtypes were determined by phylogenetic analysis. 【Results】 HIV RNA was successfully genotyped in 174 samples from HIV-infected donors. The main subtypes among Dalian blood donors were CRF01_AE(69.5%), CRF07_BC(17.2%), B(5.2%), CRF02_AG(2.9%), C(1.1%), CRF55_01B(1.1%), CRF08_BC(0.6%), CRF59_01B(0.6%) and CRF79_0107(0.6%). There were still 2 cases (1.1%) unclassified. Significant difference was observed when comparing with the published national data. The prevalence of CRF01_AE strains decreased over the years, while CRF07_BC increased significantly. CRF02_AG carriers differed from donors infected with other HIV subtypes by being mostly females (40.0% vs. 2.4%), aged (median: 35y vs. 26y) and lower educational background(junior school degree or below). And 96.7% of local CRF01_AE cases were related to HIV strains, which were reported to circulate in Northeast China and in the MSM population. 【Conclusion】 HIV-1 among Dalian blood donors had unique molecular epidemiology and the trends of 07_BC increasing and 01_AE decreasing lagged behind the overall national data. Donor education on blood safety and consultation services to high risk group before donation still need improvement.

【Objective】 To investigate the serological and molecular characteristics of HBsAg+ /HBV DNA non-reactive (NR) infections. 【Methods】 Samples tested as HBsAg+ and HBV DNA NR were confirmed by individual NAT repeat testing, viral particle concentration by PEG precipitation combined with in-house nested PCR and real-time quantitative PCR, anti-HBc testing, and HBsAg quantification. HBV sequences were compared with those from donors with chronic and occult infection as controls. 【Results】 A total of 792 195 samples were screened between January 2011 and December 2020, of which 53 (1: 14 947) were confirmed HBsAg+ /HBV DNA NR. HBV DNA was detected further in five (9.4%) samples; three S sequences and four Pre Core/Core sequences were obtained. Unique amino acid substitutions (P130T, P135Q/S, R151Q, G153S and S155F) were found in the Core protein that may affect virus packaging and replication. 【Conclusion】 Extremely low HBV DNA level was detected in plasmas of HBsAg+ /HBV DNA NR donors. Barely detectable HBV DNA might be associated with unusual mutations in the Pre Core/Core protein affecting viral replication. More sensitive HBV DNA and/or HBsAg assays may be considered to further reduce the potential HBV transfusion-transmission residual risk.