Abstract: Objective This study is to investigate the residual risk of HIV transmission among blood donors in Changsha city from 2014 to 2022. Methods The blood screening results of unpaid blood donors from January 1, 2014 to December 31, 2022 in Changsha Blood Center and the confirmed results fed back by the Center for Disease Control and Prevention (CDC) were retrospectively analyzed through the blood station information management system, and the residual risk of HIV screening of unpaid blood donors was assessed using the incidence rate window mathematical model. Results During the study period, the HIV positive rate in the Changsha area was 0.199 5 ‰ (273/1 368 333), among first-time blood donors was 757 455 accounting for 55.36%, the HIV positive rate was 0.249 5 ‰ (189/757 455) and the repeat blood donors was 610878 accounting for 44.64%, the HIV positive rate was 0.1375 ‰ (84/610 878). There was a statistical difference in the positive rates between the first and repeat blood donors (χ²=21.270, P<0.001). The residual risk of HIV among first-time blood donors was 1/204 081.63, which is higher than that of repeat blood donors by 1/370 370.37. The residual risk of HIV is 1/85 470 in the two-time enzyme-linked immunosorbent assay (ELISA). After HIV Nucleic acid test (NAT) blood screening, the residual risk was reduced to 1/250 000. NAT screening can reduce the residual risk by 65.81%. Conclusion The assessment of residual risks may help to evaluate the impact of different testing strategies on blood safety and ensure blood quality

Key words: HIV, Residual risk of blood transfusion, Incidence rate-window model, Blood donors