SARS-CoV-2 antigen and antibody prevalence among UK staff working with cancer patients during the COVID-19 pandemic

Abstract

AbstractBackgroundInternational guidelines for testing potentially immunosuppressed cancer patients receiving non-surgical anticancer therapies for SARS-CoV-2 (COVID-19) are currently lacking. The value of routinely testing staff treating cancer patients is not known.MethodsPatient-facing oncology department staff at work during the COVID-19 pandemic consented to have a nasopharyngeal swab SARS-CoV-2 antigen test by polymerase chain reaction (PCR) and blood tests for SARS-CoV-2 antibody using a laboratory Luminex-based assay and a rapid point-of-care (POC) assay on 2 occasions 28 days apart in June and July 2020.Findings434 participants were recruited: nurses (58·3%), doctors (21·2%), radiographers (10·4%) and administrators (10·1%). 82% were female; median age 40-years (range 19-66). 26·3% reported prior symptoms suggestive of SARS-CoV-2 infection and 1·4% tested PCR-positive prior to June 2020. All were PCR-negative at both study day 1 and 28. 18·4% were SARS-CoV-2 sero-positive on day 1 by Luminex, of whom 42·5% also tested positive by POC. 47·5% of Luminex sero-positives had antibodies to both nucleocapsid (N) and surface (S) antigens. Nurses (21·3%) and doctors (17·4%) had higher prevalence trends of Luminex sero-positivity compared with administrators (13·6%) and radiographers (8·9%) (p=0.2). 38% of sero-positive participants reported previous symptoms suggestive of SARS-CoV-2 infection, a 1·9-fold higher odds than sero-negative participants (p=0·01). 400 participants re-tested on day 28: 13·3% were Luminex sero-positive of whom 92·5% were previously positive and 7·5% newly positive. Nurses (16·5%) had the highest seroprevalence trend amongst staff groups (p=0·07). 32·5% of day 1 sero-positives became sero-negative by day 28: the majority being previously reactive to the N-antigen only (p<0·0001).InterpretationThe high prevalence of SARS-CoV-2 IgG sero-positivity in oncology nurses, and the high decline of positivity over 4 weeks supports regular antigen and antibody testing in this staff group for SARS-CoV-2 as part of routine patient care prior to availability of a vaccine.FundingACT, NHSEvidence before this studyTo identify studies involving oncology healthcare workers and SARS-CoV-2 exposure during the COVID-19 pandemic, we searched PubMed and Medrxiv for articles published between January 1 and July 31 using the following search terms “COVID-19”, “SARS-CoV-2”, “oncology staff”, “healthcare workers” without language restriction. To date, no large study has specifically reported and tracked patient-facing oncology staff SARS-CoV-2 exposure.Added value of this studyTo the best of our knowledge, this is the first study specifically investigating SARS-CoV-2 exposure in UK patient-facing oncology staff who were at work during the peak of the COVID-19 pandemic between March and June 2020. 18·4% of staff were SARS-CoV-2 antibody positive at the start of June 2020 suggesting prior SARS-CoV-2 infection, while 32·5% of those antibody-positive cases became antibody-negative 28 days after the first sample collection. The highest seroprevalence rates at both time points were recorded in nurses.Implications of all the available evidenceThese results justify incorporating SARS-CoV-2 PCR and antibody testing of oncology nurses into international guidelines for managing cancer patients treated with non-surgical anticancer treatments prior to availability of a functional vaccine.