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Observational Study
. 2022 Feb 5;11(1):27.
doi: 10.1186/s13756-022-01070-6.

Impact of respirator versus surgical masks on SARS-CoV-2 acquisition in healthcare workers: a prospective multicentre cohort

Sabine Haller  1   2 , Sabine Güsewell  3 , Thomas Egger  1 , Giulia Scanferla  1 , Reto Thoma  1 , Onicio B Leal-Neto  4   5 , Domenica Flury  1 , Angela Brucher  6 , Eva Lemmenmeier  7 , J Carsten Möller  8 , Philip Rieder  9 , Markus Rütti  10 , Reto Stocker  9 , Danielle Vuichard-Gysin  11   12 , Benedikt Wiggli  13 , Ulrike Besold  14 , Stefan P Kuster  15 , Allison McGeer  16 , Lorenz Risch  17   18   19 , Matthias Schlegel  1 , Andrée Friedl  13 , Pietro Vernazza  1 , Christian R Kahlert #  1   20 , Philipp Kohler #  21
Affiliations
Observational Study

Impact of respirator versus surgical masks on SARS-CoV-2 acquisition in healthcare workers: a prospective multicentre cohort

Sabine Haller et al. Antimicrob Resist Infect Control. .

Abstract

Background: There is insufficient evidence regarding the role of respirators in the prevention of SARS-CoV-2 infection. We analysed the impact of filtering facepiece class 2 (FFP2) versus surgical masks on the risk of SARS-CoV-2 acquisition among Swiss healthcare workers (HCW).

Methods: Our prospective multicentre cohort enrolled HCW from June to August 2020. Participants were asked about COVID-19 risk exposures/behaviours, including preferentially worn mask type when caring for COVID-19 patients outside of aerosol-generating procedures. The impact of FFP2 on (1) self-reported SARS-CoV-2-positive nasopharyngeal PCR/rapid antigen tests captured during weekly surveys, and (2) SARS-CoV-2 seroconversion between baseline and January/February 2021 was assessed.

Results: We enrolled 3259 participants from nine healthcare institutions, whereof 716 (22%) preferentially used FFP2. Among these, 81/716 (11%) reported a SARS-CoV-2-positive swab, compared to 352/2543 (14%) surgical mask users; seroconversion was documented in 85/656 (13%) FFP2 and 426/2255 (19%) surgical mask users. Adjusted for baseline characteristics, COVID-19 exposure, and risk behaviour, FFP2 use was non-significantly associated with decreased risk for SARS-CoV-2-positive swab (adjusted hazard ratio [aHR] 0.8, 95% CI 0.6-1.0) and seroconversion (adjusted odds ratio [aOR] 0.7, 95% CI 0.5-1.0); household exposure was the strongest risk factor (aHR 10.1, 95% CI 7.5-13.5; aOR 5.0, 95% CI 3.9-6.5). In subgroup analysis, FFP2 use was clearly protective among those with frequent (> 20 patients) COVID-19 exposure (aHR 0.7 for positive swab, 95% CI 0.5-0.8; aOR 0.6 for seroconversion, 95% CI 0.4-1.0).

Conclusions: Respirators compared to surgical masks may convey additional protection from SARS-CoV-2 for HCW with frequent exposure to COVID-19 patients.

Keywords: Aerosol; COVID-19; Healthcare workers; Respirator; Surgical mask.

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Conflict of interest statement

None of the co-authors reports any conflict of interest.

Figures

Fig. 1
Fig. 1
Study timeline and procedures in relation to laboratory confirmed (by polymerase chain reaction [PCR] or rapid antigen test) COVID-19 cases in Switzerland (absolute number of weekly cases)
Fig. 2
Fig. 2
Forest plots showing results of the multivariable Cox regression analysis with outcome “SARS-CoV-2-positive nasopharyngeal PCR/rapid antigen test” (participants n = 3259, positive swabs n = 433) (AGP aerosol-generating procedure, FFP2 filtering facepiece class 2)
Fig. 3
Fig. 3
Forest plots showing results of the generalized mixed-effects model regarding outcome “SARS-CoV-2 seroconversion” (participants n = 2916, seroconversions n = 511) (AGP aerosol-generating procedure, FFP2 filtering facepiece class 2)
Fig. 4
Fig. 4
Kaplan–Meier curve regarding unadjusted risk of a SARS-CoV-2-positive nasopharyngeal swab for healthcare workers (HCW) with infrequent (a) and frequent (b) exposure to COVID-19 patients (FFP2 filtering facepiece class 2)
See this image and copyright information in PMC

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