SARS-CoV-2 Screening Among Symptom-Free Healthcare Workers
Authors: Demmer Ryan T. , Ulrich Angela K. , Wiggen Talia D. , Strickland Ali , Naumchik Brianna M. , Kulasingam Shalini , Stovitz Steven D. , Marotz Clarisse , Belda-Ferre Pedro , Humphrey Greg , De Hoff Peter , Laurent Louise , Kline Susan , Knight Rob 
Published: August 2020

Importance

Transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is possible among symptom-free individuals and some patients are avoiding medically necessary healthcare visits for fear of becoming infected in the healthcare setting. Limited data are available on the point prevalence of SARS-CoV-2 infection in U.S. healthcare workers (HCW).

Objective

To estimate the prevalence of SARS-CoV-2 infection and to assess the acceptability of self-collected NPS among HCW.

Design

Cross-sectional convenience sample enrolled between April 20thand June 24th, 2020. We had >95% power to detect at least one positive test if the true underlying prevalence of SARS-CoV2 was ≥1%.

Setting

The metropolitan area surrounding Minneapolis and St. Paul, Minnesota.

Participants

HCW free of self-reported upper respiratory symptoms were recruited.

Exposures

Participants completed questionnaires regarding demographics, household characteristics, personal protective equipment (PPE) utilization and comorbidities.

Outcomes

A participant self-collected nasopharyngeal swab (NPS) was obtained. SARS-CoV-2 infection was assessed via polymerase chain reaction. NPS discomfort was assessed on a scale of 1 (no discomfort) – 10 (extreme discomfort). NPS duration and depth into the nasopharynx, and willingness to perform future self-collections were assessed.

Results

Among n=489 participants 80% were female and mean age±SD was 41±11. Participants reported being physicians (14%), nurse practitioners (8%), physician’s assistants (4%), nurses (51%), medics (3%), or other which predominantly included laboratory technicians and administrative roles (22%). Exposure to a known/suspected COVID-19 case in the 14 days prior to enrollment was reported in 40% of participants. SARS-CoV-2 was not detected in any participant. The mean±SD discomfort level of the NPS was 4.5±2.0. Participants overwhelmingly reported that their self-swabs was ≥ the duration and depth of patient swabs they had previously performed. Over 95% of participants reported a willingness to repeat a self-collected NP swab in the future.

Conclusions and Relevance

The point prevalence of SARS-CoV-2 infection was likely <1% in a convenience sample of symptom-free Minnesota healthcare workers from April 20thand June 24th, 2020. Self-collected NP swabs are well-tolerated and a viable alternative to provider-collected swabs to preserve PPE.

KEY POINTS

Questions

What is the point prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among symptom-free healthcare workers (HCW) and what is the acceptability of self-collected nasopharyngeal swabs (NPS) for SARS-CoV-2 infection ascertainment?

Findings

SARS-CoV-2 was not detected in any of 489 HCWs studied. Self-collected NPS were well tolerated and over 95% of participants reported a willingness to repeat a self-collected NP swab in the future.

Meaning

The point prevalence of SARS-CoV-2 infection was likely very low in a convenience sample of symptom-free Minnesota healthcare workers from April 20thand June 24th, 2020.