University of Massachusetts Medical School Faculty Publications

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Department of Pathology

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Article Preprint


Amino Acids, Peptides, and Proteins | Epidemiology | Immunology of Infectious Disease | Immunopathology | Infectious Disease | Microbiology | Virus Diseases


Background: A seroprevalence study can estimate the percentage of people with SARS-CoV-2 antibodies in the general population, however, most existing reports have used a convenience sample, which may bias their estimates.

Methods: We sought a representative sample of Connecticut residents, aged ≥18 years and residing in non-congregate settings, who completed a survey between June 4 and June 23, 2020 and underwent serology testing for SARS-CoV-2-specific IgG antibodies between June 10 and July 29, 2020. We also oversampled non-Hispanic Black and Hispanic subpopulations. We estimated the seroprevalence of SARS-CoV-2-specific IgG antibodies and the prevalence of symptomatic illness and self-reported adherence to risk mitigation behaviors among this population.

Results: Of the 567 respondents (mean age 50 [±17] years; 53% women; 75% non-Hispanic White individuals) included at the state-level, 23 respondents tested positive for SARS-CoV-2-specific antibodies, resulting in weighted seroprevalence of 4.0 (90% confidence interval [CI] 2.0-6.0). The weighted seroprevalence for the oversampled non-Hispanic Black and Hispanic populations was 6.4% (90% CI 0.9-11.9) and 19.9% (90% CI 13.2-26.6), respectively. The majority of respondents at the state-level reported following risk mitigation behaviors: 73% avoided public places, 75% avoided gatherings of families or friends, and 97% wore a facemask, at least part of the time.

Conclusions: These estimates indicate that the vast majority of people in Connecticut lack antibodies against SARS-CoV-2 and there is variation by race/ethnicity. There is a need for continued adherence to risk mitigation behaviors among Connecticut residents to prevent resurgence of COVID-19 in this region.


Seroprevalence, SARS-CoV-2, COVID-19, Antibodies, Connecticut, Epidemiology

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medRxiv 2020.08.04.20168203; doi: View preprint on medRxiv


This article is a preprint. Preprints are preliminary reports of work that have not been certified by peer review.

The PDF available for download is Version 2 of this preprint. The complete version history of this preprint is available at medRxiv. Version 1 is also available in eScholarship@UMMS.

Full author list omitted for brevity. For the full list of authors, see preprint.

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Now published in The American Journal of Medicine doi: 10.1016/j.amjmed.2020.09.024

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Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.