The Change in Seroprevalence in the US plus Puerto Rico between May and September of SARS-CoV-2 Antibody in the Asymptomatic Population

ObjectiveDetermine the seroprevalence and 3 month temporal change of SARS-COV-2 in the US and Puerto Rico in an asymptomatic well population. ResultsThe prevalence of SARS-CoV-2 in the asymptomatic population has doubled during the May to September time period, going from 3.0% to 6.6%. Positive serology to SARS-COV-2 was similar in males and females but varies by age. The greatest increase was in the youngest population. Based on the September prevalence it is estimated that there are 11.1 million (bootstrap 95% CI: 10.8 - 11.5 million) asymptomatic SARS-CoV-2 infections in the US, which is 1.95 times the cumulative number of cases in the US reported to the CDC as of September 1, 2020. ConclusionsThe number of new SARS-COV-2 cases more than doubled in this 3 months period. The seroprevalence by age group is high in the youngest ( 70, 2.0%). Over the three month study period the rate of increase in prevalence for SARS-COV-2 serology varies by state with a range from 0.84 (State of New York) to more than 12 (Tennessee). This study identifies states were public health mitigation has blunted the spread and also areas where additional levels of intensified public education, surveillance and targeted intervention may be warranted. ObjectiveDetermine the rate of change in prevalence of SARS-COV-2 antibody in a self-reported asymptomatic well population over a three month period. MethodBetween 12 May and 25 September we examined SARS-COV-2 antibody results on 113,369 consecutive life insurance applicants who were having blood drawn for the purpose of underwriting mortality risk. ResultsIn May the seroprevalence of SARS-CoV-2 was 3.0%(547/18,441), 3.1%(981/31,822) in June and 6.6%(4180/63,103) in September. Positive serology to SARS-COV-2 was similar in males and females but varies by age. Geographical distribution revealed a very high level of various between states. Using 2019 US Census state population data to adjust state specific rates of positivity, it is estimated that the September level of seropositivity would correspond to 11.1 million asymptomatic SARS-CoV-2 infections in the US, which is roughly 2 times the cumulative number of cases in the US reported to the CDC as of September 1, 2020. ConclusionsThe prevalence of positive SARS-COV-2 serology increased more than 2 fold during the three month period from May to September 2020 going from 3.0% to 6.6%. During this period state specific rates of increase in prevalence vary wildly from 0.8(New York) to more than 12 fold (Tennessee). The estimated number of total SARS-CoV-2 infections based on positive serology is substantially higher than the total number of cases reported to the CDC. This study identifies states were public health mitigation has blunted the spread and also areas where additional levels of intensified public education, surveillance and targeted intervention may be warranted.