Risk factors and protective measures for healthcare worker infection during highly infectious viral respiratory epidemics: a systematic review and meta-analysis.

Tian, Chenchen; Lovrics, Olivia; Vaisman, Alon; Chin, Ki Jinn; Tomlinson, George; Lee, Yung; Englesakis, Marina; Parotto, Matteo; Singh, Mandeep

OBJECTIVE To investigate risk factors for HCW infection in viral respiratory pandemics (SARS-CoV-2, MERS, SARS CoV-1, influenza A H1N1, influenza H5N1) and improve understanding of HCW risk management amidst the COVID-19 pandemic. DESIGN Systematic review and meta-analysis. METHODS MEDLINE, EMBASE, CINAHL, and Cochrane CENTRAL databases were searched from conception until July 2020 for studies comparing infected HCWs (cases) and non-infected HCWs (controls) and risk factors for infection. Outcomes included HCW types, infection prevention practices, and medical procedures. Pooled effect estimates with pathogen-specific stratified meta-analysis and inverse variance meta-regression analysis were completed. GRADE framework was used to rate certainty of evidence. PROSPERO (CRD42020176232) 6 April 2020. RESULTS Fifty-four comparative studies were included (n=191,004 HCWs). Compared to non-frontline HCWs, frontline HCWs were at increased infection risk (OR 1.66 95%CI 1.24 to 2.22) and greater for HCWs involved in endotracheal intubations (risk difference [95%CI]: 35.2% [21.4 to 47.9]). Use of gloves, gown, surgical mask, N95 respirator, face protection, and infection training were each strongly protective against infection. Meta-regression showed reduced infection risk in frontline HCWs working in facilities with infection designated wards (OR -1.04, 95%CI -1.53 to -0.33, p=0.004) and performing aerosol-generating medical procedures in designated centres (OR -1.30 95%CI -2.52 to -0.08; p=0.037). CONCLUSIONS During highly infectious respiratory pandemics, widely available protective measures such as use of gloves, gowns, and face masks are strongly protective against infection and should be instituted, preferably in dedicated settings, to protect frontline HCW during waves of respiratory virus pandemics.