ABSTRACT
Background: Reported COVID-19 cases underestimate SARS-CoV-2 infections. We conducted a national probability survey of US households to estimate the cumulative incidence of infection adjusted for antibody waning.Methods: From August to December 2020, a multistage random sample of US addresses were mailed a survey and materials to self-collect nasal swabs and dried blood spots. One adult household member was randomly selected to complete the survey and mail specimens for virus and antibody testing. We estimated cumulative incidence of SARS-CoV-2 infections adjusted for waning antibodies and calculated reported fraction and infection fatality ratio (IFR). Differences in seropositivity among demographic, geographic and clinical subgroups were explored with weighted prevalence ratios (PR).Results: Among 39,500 sampled households, 4,654 respondents provided surveys and valid specimens. Cumulative incidence adjusted for waning was 11.9% (95% credible interval (CrI): 10.5-13.5%) as of October 30, 2020. We estimated 30,332,842 (95% CrI: 26,703,753-34,335,338) total infections in the U.S. adult population by October 30, 2020.The reported fraction was 17% and the IFR was 0.85% among adults. Non-Hispanic Black (PR: 2.2) and Hispanic (PR: 3.1) persons were significantly more likely than White non-Hispanic to be seropositive, as were those living in metropolitan areas (PR: 2.5).Conclusions: One in 8 US adults had been infected with SARS-CoV-2, but few had been accounted for in public health reporting. Our data document that the scope of the COVID-19 pandemic is likely substantially underestimated by reported cases. Disparities in COVID-19 by race observed among reported cases cannot be attributed to differential diagnosis or reporting of infections in some population subgroups.Funding Statement: This project was funded by the National Institute of Allergy andInfectious Diseases, grant number 3R01AI143875-02S1, This project was partially funded by The Epidemiology and Laboratory Capacity for Infectious Diseases, Grant Number 6 NU50CK000539. This project was partially funded by the Woodruff Foundation.Declaration of Interests: The authors declare no conflict of interest.Ethics Approval Statement: The COVIDVu study was approved by the Emory University Institutional Review Board (STUDY00000695).
Subject(s)
COVID-19 , Hypersensitivity , Communicable DiseasesABSTRACT
Background: Options to increase the ease of testing for SARS-CoV-2 infection and immune response are needed. Self-collection of diagnostic specimens at home offers an avenue to allow people to test for SARS-CoV-2 infection or immune response without traveling to a clinic or laboratory. Before this study, survey respondents indicated willingness to self-collect specimens for COVID-related tests, but hypothetical willingness can differ from post-collection acceptability after participants collect specimens. Methods: 153 US adults were enrolled in a study of the willingness and feasibility of patients to self-collect three diagnostic specimens (saliva, oropharyngeal swab (OPS) and dried blood spot (DBS) card) while observed by a clinician through a telehealth session. After the specimens were collected, 148 participants participated in a survey about the acceptability of the collection, packing and shipping process, and their confidence in the samples collected for COVID-related laboratory testing. Results: A large majority of participants (>84%) reported that collecting, packing and shipping of saliva, OPS, and DBS specimens were acceptable. Nearly nine in 10 (87%) reported being confident or very confident that the specimens they collected were sufficient for laboratory analysis. There were no differences in acceptability for any specimen type, packing and shipping, or confidence in samples by gender, age, race/ethnicity, or educational level. Conclusions: Self-collection of specimens for SARS-CoV-2 testing and preparing and shipping specimens for analysis were acceptable in a diverse group of US adults. Further refinement of materials and instructions to support self-collection of saliva, OPS and DBS specimens for COVID-related testing is needed.