SARS-CoV-2 infection rates and associated risk factors in healthcare workers: systematic review and meta-analysis

To protect healthcare workforce during the COVID-19 pandemic, rigorous efforts were made to reduce infection rates among healthcare workers (HCWs), especially prior to vaccine availability. This study aimed to investigate the prevalence of SARS-CoV-2 infections among HCWs and identify potential risk factors associated with transmission. We searched MEDLINE, Embase, and Google Scholar from 1 December 2019 to 5 February 2024. From 498 initial records, 190 articles were reviewed, and 63 studies were eligible. ROBINS-E tool revealed a lower risk of bias in several domains; however, some concerns related to confounding and exposure measurement were identified. Globally, 11% (95% confidence interval (CI) 9-13) of 283,932 HCWs were infected with SARS-CoV-2. Infection rates were associated with a constellation of risk factors and major circulating SARS-CoV-2 variants. Household exposure (odds ratio (OR) 7.07; 95% CI 3.93-12.73), working as a cleaner (OR 2.72; 95% CI 1.39-5.32), occupational exposure (OR 1.79; 95% CI 1.49-2.14), inadequate training on infection prevention and control (OR 1.46; 95% CI 1.14-1.87), insufficient use of personal protective equipment (OR 1.45; 95% CI 1.14-1.84), performing aerosol generating procedures (OR 1.36; 95% CI 1.21-1.52) and inadequate hand hygiene (OR 1.17; 95% CI 0.79-1.73) were associated with an increased SARS-CoV-2 infection. Conversely, history of quarantine (OR 0.23; 95% CI 0.08-0.60) and frequent decontamination of high touch areas (OR 0.52; 95% CI 0.42-0.64) were protective factors against SARS-CoV-2 infection. This study quantifies the substantial global burden of SARS-CoV-2 infection among HCWs. We underscore the urgent need for effective infection prevention and control measures, particularly addressing factors such as household exposure and occupational practices by HCWs, including cleaning staff.