Screening and Analysis of SARS-CoV-2 Antibody Among Unvaccinated Blood Donors in Chongqing, China

Objective: To investigate the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody among unvaccinated voluntary blood donors in Chongqing, and to provide evidence for epidemic surveillance.Methods: A total of 10,208 voluntary blood donors from January 5 to January 20, 2021, in the Chongqing area were collected, and the SARS-CoV-2 immunoglobulin (Ig) G and IgM antibodies were detected by chemiluminescence, and the differences of antibody-positive rate in different gender, age, ABO blood group, and different risk areas were analyzed.Results: Among 10208 blood donors, 10 were found to be positive for SARS-COV-2 IgG antibody, giving a positivity rate of SARS-COV-2 IgG at 0.10%, and 29 were positive for SARS-CoV-2 IgM antibody, with a positivity rate of SARS-CoV-2 IgM at 0.28%. There was no statistical difference in the positive rate of antibody among different genders, ages, and ABO blood types, but it was related to the number of confirmed coronavirus disease 2019 (COVID-19) cases in each city.Conclusions: The SARS-CoV-2 seroprevalence rate in Chongqing was low and correlated with the number of confirmed COVID-19 cases.