Undiagnosed SARS-CoV-2 seropositivity during the first 6 months of the COVID-19 pandemic in the United States

Abstract

Asymptomatic SARS-CoV-2 infection and delayed implementation of diagnostics have led to poorly defined viral prevalence rates in the United States and elsewhere. To address this, we analyzed seropositivity in 9,089 adults in the United States who had not been diagnosed previously with COVID-19. Individuals with characteristics that reflected the US population (n = 27,716) were selected by quota sampling from 462,949 volunteers. Enrolled participants (n = 11,382) provided medical, geographic, demographic, and socioeconomic information, and dried blood samples. Survey questions coincident with the Behavioral Risk Factor Surveillance System survey, a large probability-based national survey, were used to adjust for selection bias. The majority (88.7%) of blood samples were collected between May 10th and July 31st, 2020 and were processed using ELISA to measure seropositivity (IgG and IgM antibodies against SARS-CoV-2 spike protein and the spike protein receptor binding domain). The overall weighted undiagnosed seropositivity estimate was 4.6% (95% CI: 2.6-6.5%) with race, age, sex, ethnicity, and urban/rural subgroup estimates ranging from 1.1% to 14.2%; the highest seropositivity estimates were in African American participants, younger, female, and Hispanic participants, and residents of urban centers. These data indicate that there were 4.8 undiagnosed SARS-CoV-2 infections for every diagnosed case of COVID-19, and an estimated 16.8 million infections were undiagnosed by mid-July 2020 in the United States.

The Unrecognized Death Toll of COVID-19 in the United States

“…In the United States (US), the COVID-19 pandemic has caused more than 33 million confirmed infections and over 600,000 reported deaths as of July 1, 2021. However, recent estimates of undiagnosed infections 1 and under-reported deaths [2] , [3] , [4] demonstrate that the true burden of COVID-19 in the US, and likely in other countries, has not been fully captured.…”

Data-driven identification of temporal glucose patterns in a large cohort of nondiabetic patients with COVID-19 using time-series clustering

“…In addition, recent work suggests that asymptomatic COVID-19 cases are more prevalent than previously thought. 68 Therefore, these results may represent glycemic changes in a more severe spectrum of COVID-19 cases. Next, this study only included individuals with glucose measurements before, during, and after COVID-19, resulting in a significant reduction of patients from the original cohort (Supplementary Figure S1).…”

SARS-CoV-2 Neutralization in Convalescent Plasma and Commercial Lots of Plasma-derived Immunoglobulin

“…The reported COVID-19 prevalence in 07/2020 was about 1% [40], while recent reports suggest a 4.8 fold higher seroprevalence during the first wave of the pandemic [46]. In fact a recent serological survey among US blood donors showed a 3.5% seroprevalence in July 2020 [47].…”