SARS-CoV-2 Seroprevalence Survey Estimates Are Affected by Anti-Nucleocapsid Antibody Decline. (5th January 2021)

• Record Type: Journal Article
• Authors: Bolotin, Shelly; Tran, Vanessa; Osman, Selma; Brown, Kevin A; Buchan, Sarah A; Joh, Eugene; Deeks, Shelley L; Allen, Vanessa G
• Is Part Of: Journal of infectious diseases. Volume 223:Number 8(2021)
• Page Start: 1334
• Page End: 1338
• Publication Date: 2021-01-05
• Subjects: COVID-19 -- SARS-CoV-2 -- serology -- seroprevalence; Communicable diseases -- Periodicals; Diseases -- Causes and theories of causation -- Periodicals; Medicine -- Periodicals; Communicable Diseases -- Periodicals; Electronic journals; 616.9
• DOI: 10.1093/infdis/jiaa796
• Languages: English
• ISSNs: 0022-1899

Abstract

Abstract: We analyzed 21 676 residual specimens from Ontario, Canada collected March–August 2020 to investigate the effect of antibody decline on SARS-CoV-2 seroprevalence estimates. Testing specimens orthogonally using Abbott (anti-nucleocapsid) and Ortho (anti-spike) assays, seroprevalence estimates were 0.4%–1.4%, despite ongoing disease activity. The geometric mean concentration (GMC) of antibody-positive specimens decreased over time ( P = .015), and GMC of antibody-negative specimens increased over time ( P = .0018). Association between the 2 tests decreased each month ( P < .001), suggesting anti-nucleocapsid antibody decline. Lowering Abbott antibody index cutoff from 1.4 to 0.7 resulted in a 16% increase in positive specimens.