SARS-CoV-2 anti-N antibodies among healthcare personnel without previous known COVID-19

Objective: To measure SARS-CoV-2 anti-nucleocapsid (anti-N) antibody seropositivity among healthcare personnel (HCP) without a history of COVID-19 and to identify HCP characteristics associated with seropositivity. Design: Prospective cohort study from September 22, 2020, to March 3, 2022. Setting: A tertiary care academic medical center. Participants: 727 HCP without prior positive SARS-CoV-2 PCR testing were enrolled; 559 HCP successfully completed follow-up. Methods: At enrollment and follow-up 1-6 months later, HCP underwent SARS-CoV-2 anti-N testing and were surveyed on demographics, employment information, vaccination status, and COVID-19 symptoms and exposures. Results: Of 727 HCP enrolled, 27 (3.7%) had a positive SARS-CoV-2 anti-N test at enrollment. Seropositive HCPs were more likely to have a household exposure to COVID-19 in the past 30 days (OR 7.92, 95% CI 2.44-25.73), to have had an illness thought to be COVID-19 (4.31, 1.94-9.57), or to work with COVID-19 patients more than half the time (2.09, 0.94-4.77). Among 559 HCP who followed-up, 52 (9.3%) had a positive SARS-CoV-2 anti-N antibody test result. Seropositivity at follow-up was associated with community/household exposures to COVID-19 within the past 30 days (9.50, 5.02-17.96; 2.90, 1.31-6.44), having an illness thought to be COVID-19 (8.24, 4.44-15.29), and working with COVID-19 patients more than half the time (1.50, 0.80-2.78). Conclusions: Among HCP without prior positive SARS-CoV-2 testing, SARS-CoV-2 anti-N seropositivity was comparable to that of the general population and was associated with COVID-19 symptomatology and both occupational and non-occupational exposures to COVID-19.