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Table 2 Antibody test results and seroprevalence estimates overall and by sex, age and race/ethnicity. Seroprevalence estimates reported in terms of posterior mode and 95% credible interval, calculated using Bayesian method that adjusts for test sensitivity and specificity. Estimates not reported for categories with 25 test results or fewer. Excludes 11 positive CP/WB Donors and 2 CP/WB donors that tested negative for all three tests. *Posterior mode calculated using a prior distribution having mode equal to the overall seroprevalence for IgM

From: Low Seroprevalence of SARS-CoV-2 in Rhode Island blood donors during may 2020 as determined using multiple serological assay formats

   Number Positive Seroprevalence Estimates (95% CI)
N IgG IgM Ortho IgG IgM Ortho
Overall 1996 13 68 14 0.6 (0.3 to 1.1) 2.7 (1.7 to 3.8) 0.6 (0.2 to 1.1)
Sex
 Men 1057 9 32 11 0.8 (0.4 to 1.6) 2.2 (1.1 to 3.8) 0.9 (0.3 to 1.8)
 Women 939 4 36 3 0.3 (0.1 to 1.1) 3.1 (1.8 to 5.0) 0.1 (0 to 0.9)
Age
 15–34 348 2 4 5 0.6 (0.1 to 2.1) 0.2 (0 to 2.4) 1.3 (0.4 to 3.4)
 35–64 1181 5 45 6 0.4 (0.1 to 1.0) 3.3 (1.9 to 4.8) 0.4 (0 to 1.0)
 65+ 467 6 19 3 1.2 (0.5 to 2.8) 3.4 (1.6 to 6.1) 0.5 (0.1 to 1.8)
Race/Ethnicity
 Asian 5 0 0 0    
 Black/African American 11 0 0 0    
 Hispanic/Latino 54 1 0 1 1.9 (0.4 to 10.2) 0.5 (0 to 7.7) * 1.8 (0.3 to 10.3)
 Native American 5 0 0 0    
 White 1688 10 57 11 0.5 (0.2 to 1.1) 2.7 (1.6 to 3.9) 0.5 (0.1 to 1.1)
 Other / Multiple 24 0 2 0    
 Unknown / Declined 209 2 8 2 0.9 (0.2 to 3.5) 3.0 (0.9 to 7.5) 0.8 (0.1 to 3.5)