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. 2022 Jan-Feb;137(1):128-136.
doi: 10.1177/00333549211055137. Epub 2021 Nov 9.

Assessment of SARS-CoV-2 Seroprevalence by Community Survey and Residual Specimens, Denver, Colorado, July-August 2020

Kiersten J Kugeler  1 , Laura J Podewils  2 , Nisha B Alden  3 , Tori L Burket  2 , Breanna Kawasaki  3 , Brad J Biggerstaff  1 , Holly M Biggs  1 , Rachael Zacks  1 , Monique A Foster  1 , Travis Lim  1 , Emily McDonald  1 , Jacqueline E Tate  1 , Rachel K Herlihy  3 , Jan Drobeniuc  1 , Margaret M Cortese  1
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Assessment of SARS-CoV-2 Seroprevalence by Community Survey and Residual Specimens, Denver, Colorado, July-August 2020

Kiersten J Kugeler et al. Public Health Rep. 2022 Jan-Feb.

Abstract

Objectives: The number of SARS-CoV-2 infections is underestimated in surveillance data. Various approaches to assess the seroprevalence of antibodies to SARS-CoV-2 have different resource requirements and generalizability. We estimated the seroprevalence of antibodies to SARS-CoV-2 in Denver County, Colorado, via a cluster-sampled community survey.

Methods: We estimated the overall seroprevalence of antibodies to SARS-CoV-2 via a community seroprevalence survey in Denver County in July 2020, described patterns associated with seroprevalence, and compared results with cumulative COVID-19 incidence as reported to the health department during the same period. In addition, we compared seroprevalence as assessed with a temporally and geographically concordant convenience sample of residual clinical specimens from a commercial laboratory.

Results: Based on 404 specimens collected through the community survey, 8.0% (95% CI, 3.9%-15.7%) of Denver County residents had antibodies to SARS-CoV-2, an infection rate of about 7 times that of the 1.1% cumulative reported COVID-19 incidence during this period. The estimated infection-to-reported case ratio was highest among children (34.7; 95% CI, 11.1-91.2) and males (10.8; 95% CI, 5.7-19.3). Seroprevalence was highest among males of Black race or Hispanic ethnicity and was associated with previous COVID-19-compatible illness, a previous positive SARS-CoV-2 test result, and close contact with someone who had confirmed SARS-CoV-2 infection. Testing of 1598 residual clinical specimens yielded a seroprevalence of 6.8% (95% CI, 5.0%-9.2%); the difference between the 2 estimates was 1.2 percentage points (95% CI, -3.6 to 12.2 percentage points).

Conclusions: Testing residual clinical specimens provided a similar seroprevalence estimate yet yielded limited insight into the local epidemiology of COVID-19 and might be less representative of the source population than a cluster-sampled community survey. Awareness of the limitations of various sampling strategies is necessary when interpreting findings from seroprevalence assessments.

Keywords: COVID-19; SARS-CoV-2; antibodies; seroprevalence.

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Conflict of interest statement

Declaration of Conflicting Interests: The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

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References

    1. Havers FP, Reed C, Lim T, et al.. Seroprevalence of antibodies to SARS-CoV-2 in 10 sites in the United States, March 23–May 12, 2020 (published online July 21, 2020). JAMA Intern Med. doi:10.1001/jamainternmed.2020.4130 - DOI - PubMed
    1. Yousaf AR, Duca LM, Chu V, et al.. A prospective cohort study in non-hospitalized household contacts with SARS-CoV-2 infection: symptom profiles and symptom change over time. Clin Infect Dis. 2021;73(7):e1841-e1849. doi:10.1093/cid/ciaa1072 - DOI - PMC - PubMed
    1. Oran DP, Topol EJ. Prevalence of asymptomatic SARS-CoV-2 infection: a narrative review. Ann Intern Med. 2020;173(5):362-367. doi:10.7326/M20-3012 - DOI - PMC - PubMed
    1. Clapham H, Hay J, Routledge I, et al.. Seroepidemiologic study designs for determining SARS-CoV-2 transmission and immunity. Emerg Infect Dis. 2020;26(9):1978-1986. doi:10.3201/eid2609.201840 - DOI - PMC - PubMed
    1. Shook-Sa BE, Boyce RM, Aiello AE. Estimation without representation: early severe acute respiratory syndrome coronavirus 2 seroprevalence studies and the path forward. J Infect Dis. 2020;222(7):1086-1089. doi:10.1093/infdis/jiaa429 - DOI - PMC - PubMed

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