Prevalence of antibodies to SARS-CoV-2 in Irish hospital healthcare workers

Abstract

Hospital healthcare workers (HCWs) are at increased risk of contracting COVID-19 infection. We aimed to determine the seroprevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies in HCWs in Ireland. Two tertiary referral hospitals in Irish cities with diverging community incidence and seroprevalence were identified; COVID-19 had been diagnosed in 10.2% and 1.8% of staff respectively by the time of the study (October 2020). All staff of both hospitals (N = 9038) were invited to participate in an online questionnaire and blood sampling for SARS-CoV-2 antibody testing. Frequencies and percentages for positive SARS-CoV-2 antibody were calculated and adjusted relative risks (aRR) for participant characteristics were calculated using multivariable regression analysis. In total, 5788 HCWs participated (64% response rate). Seroprevalence of antibodies to SARS-CoV-2 was 15% and 4.1% in hospitals 1 and 2, respectively. Thirty-nine percent of infections were previously undiagnosed. Risk for seropositivity was higher for healthcare assistants (aRR 2.0, 95% confidence interval (CI) 1.4–3.0), nurses (aRR: 1.6, 95% CI 1.1–2.2), daily exposure to patients with COVID-19 (aRR: 1.6, 95% CI 1.2–2.1), age 18–29 years (aRR: 1.4, 95% CI 1.1–1.9), living with other HCWs (aRR: 1.3, 95% CI 1.1–1.5), Asian background (aRR: 1.3, 95% CI 1.0–1.6) and male sex (aRR: 1.2, 95% CI 1.0–1.4). The HCW seroprevalence was six times higher than community seroprevalence. Risk was higher for those with close patient contact. The proportion of undiagnosed infections call for robust infection control guidance, easy access to testing and consideration of screening in asymptomatic HCWs. With emerging evidence of reduction in transmission from vaccinated individuals, the authors strongly endorse rapid vaccination of all HCWs.

Update Alert 10: Epidemiology of and Risk Factors for Coronavirus Infection in Health Care Workers

“…New evidence was consistent with prior updates in finding no consistent association between risk for SARS-CoV-2 infection in HCWs and age (13 studies [ 6 , 8 , 10 , 11 , 14–17 , 19 , 22–25 ]), sex (13 studies [ 6 , 8 , 10 , 11 , 13 , 14 , 16 , 17 , 19 , 22–25 ]), or HCW role (15 studies [ 6 , 7 , 11–16 , 19–25 ]) ( Supplement Table 2 ). Also consistent with prior updates, 5 studies done in the United States, Canada, or Ireland found that non-White race (Black, Asian or Asian/Pacific Islander, or combined non-White races) or Hispanic ethnicity was associated with increased risk for infection ( Supplement Table 2 ) ( 6 , 8 , 11 , 15 , 16 ).…”

“…Thirteen new studies reported on the association between exposures and likelihood of infection ( Supplement Table 3 ) ( 6–8 , 11 , 12 , 14 , 16 , 17 , 19 , 20 , 23–25 ). Seven studies ( 7 , 8 , 12 , 19 , 20 , 23 , 24 ) consistently found that exposure to COVID-19 in a household or private setting was associated with increased risk for SARS-CoV-2 infection in HCWs (adjusted odds ratios [ORs] ranged from 2.55 to 8.98) ( Supplement Table 3 ).…”

“…In most studies, household or private setting exposure was a stronger risk factor than work exposure. Nine studies found that direct contact in a work environment to patients with COVID-19 was associated with increased risk for infection ( 7 , 8 , 11 , 12 , 17 , 19 , 23–25 ).…”

Prevalence of Antibodies to SARS-CoV-2 Following Natural Infection and Vaccination in Irish Hospital Healthcare Workers: Changing Epidemiology as the Pandemic Progresses

“…Detectable antibody to SARS-CoV-2 is an excellent indicator of previous SARS-CoV-2 infection (4). A high proportion of the SARS-CoV-2 infections notified worldwide have been in hospital healthcare workers (HCW) and antibody seroprevalence has been shown to be higher in HCW than in the general population (5)(6)(7). Understanding the transmission and potential immunity dynamics of SARS-CoV-2 in hospitals is important in mitigating transmission at hospital level and adds valuable information to the growing evidence on the transmission patterns of COVID-19 among HCW.…”

SARS-CoV-2 Antibody Testing in Health Care Workers: A Comparison of the Clinical Performance of Three Commercially Available Antibody Assays

“…The primary purpose of the data collected was to estimate the seroprevalence of past SARS-CoV-2 infection in our HCW population; that analysis was carried separately as part of the PRECISE Study on Prevalence of Antibodies to SARS-CoV-2 in Irish Healthcare Workers ( 14 ). The data presented here are a secondary analysis as part of the PRECISE study, with the aim of comparing the prevalence of anti-SARS-CoV-2 antibodies in the same HCW population in two different assays targeting the anti-nucleocapsid protein, namely, Abbott Architect SARS-CoV-2 IgG assay and Roche Elecsys anti-SARS-CoV-2 immunoassay ( 15 – 17 ).…”