Efficacy of FFP3 respirators for prevention of SARS-CoV-2 infection in healthcare workers

Abstract

Background:Respiratory protective equipment recommended in the UK for healthcare workers (HCWs) caring for patients with COVID-19 comprises a fluid-resistant surgical mask (FRSM), except in the context of aerosol generating procedures (AGPs). We previously demonstrated frequent pauci- and asymptomatic severe acute respiratory syndrome coronavirus 2 infection HCWs during the first wave of the COVID-19 pandemic in the UK, using a comprehensive PCR-based HCW screening programme (Rivett et al., 2020; Jones et al., 2020).Methods:Here, we use observational data and mathematical modelling to analyse infection rates amongst HCWs working on ‘red’ (coronavirus disease 2019, COVID-19) and ‘green’ (non-COVID-19) wards during the second wave of the pandemic, before and after the substitution of filtering face piece 3 (FFP3) respirators for FRSMs.Results:Whilst using FRSMs, HCWs working on red wards faced an approximately 31-fold (and at least fivefold) increased risk of direct, ward-based infection. Conversely, after changing to FFP3 respirators, this risk was significantly reduced (52–100% protection).Conclusions:FFP3 respirators may therefore provide more effective protection than FRSMs for HCWs caring for patients with COVID-19, whether or not AGPs are undertaken.Funding:Wellcome Trust, Medical Research Council, Addenbrooke’s Charitable Trust, NIHR Cambridge Biomedical Research Centre, NHS Blood and Transfusion, UKRI.

Burden of SARS-CoV-2 infection in healthcare workers during second wave in England and impact of vaccines: prospective multicentre cohort study (SIREN) and mathematical model

“…The maintained risk in certain healthcare settings and roles after adjustment, likely due to residual confounders not included in our model, highlight the importance of understanding the nature of staff-patient contact and staff-staff mixing in different healthcare worker groups and settings, including households, 45 and consideration of whether factors such as optimisation of personal protective equipment could reduce infection rates in these at-risk groups. 46 unanswered questions and future research This study reinforces the importance of vaccination among healthcare workers during a significant wave of the SARS-CoV-2 pandemic in England: mechanisms to ensure high vaccination coverage, including boosters, throughout the workforce must be used to minimise the impact of future waves on the NHS and healthcare provision. Focused patient and participant involvement work will be essential in understanding the barriers to achieving high vaccination coverage within at-risk demographic and occupational groups, including those impeding access and increasing hesitancy.…”

“…The maintained risk in certain healthcare settings and roles after adjustment, likely due to residual confounders not included in our model, highlight the importance of understanding the nature of staff-patient contact and staff-staff mixing in different healthcare worker groups and settings, including households, 45 and consideration of whether factors such as optimisation of personal protective equipment could reduce infection rates in these at-risk groups. 46 …”

Transmission of B.1.617.2 Delta variant between vaccinated healthcare workers

“…Newly infected patients pose a risk both to other patients and to health care workers 19 , and infection of patients by HCWs is potentially a rarer event, though HCWs do pose a risk to each other 20 . Distinct approaches have been taken to reduce the risk to HCWs of infection at work; a study of the use of FFP3 respirators by HCWs in one hospital showed that these provided at least a 52% improvement in protection against infection compared to fluid resistant surgical masks 21 . Similarly, HEPA filters have suggested as a further measure in protecting patients and staff 22 and use of antiviral surface coatings has also been considered 23 .…”

Transmission of B.1.617.2 Delta Variant Between Vaccinated Healthcare Workers

“…Distinct approaches have been taken to reduce the risk to HCWs of infection at work. A study of the use of FFP3 respirators by HCWs in one hospital showed that these provided at least a 52% improvement in protection against infection compared to fluid resistant surgical masks 14 .…”