ABSTRACT
In response to the COVID-19 epidemic, Egypt established a unique care model based on quarantine hospitals where only externally-referred confirmed COVID-19 patients were admitted, and healthcare workers resided continuously over 1-to 2-week working shifts. While the COVID-19 risk for HCWs has been widely reported in standard healthcare settings, it has not been evaluated yet in quarantine hospitals. Here, we relied on longitudinal data, including results of routine RT-PCR tests, collected within three quarantine hospitals located in Cairo and Fayoum, Egypt. Using a model-based approach that accounts for the time-since-exposure variation in false-negative rates of RT-PCR tests, we computed the incidence of SARS-CoV-2 infection among HCWs. Over a total follow-up of 6,064 person-days (PD), we estimated an incidence rate (per 100 PD) of 1.05 (95% CrI: 0.58-1.65) at Hospital 1, 1.92 (95% CrI: 0.93-3.28) at Hospital 2 and 7.62 (95% CrI: 3.47-13.70) at Hospital 3. The probability for an HCW to be infected at the end of a shift was 13.7% (95% CrI: 7.8%-20.8%) and 23.8% (95% CrI: 12.2%-37.3%) for a 2-week shift at Hospital 1 and Hospital 2, respectively, which lies within the range of risk levels previously documented in standard healthcare settings, whereas it was >3-fold higher for a 7-day shift at Hospital 2 (42.6%, 95%CrI: 21.9%-64.4%). Our model-based estimates unveil a proportion of undiagnosed infections among HCWs of 46.4% (95% CrI: 18.8%-66.7%), 45.0% (95% CrI: 5.6%-70.8%) and 59.2% (95% CrI: 34.8%-78.8%), for Hospitals 1 to 3, respectively. The large variation in SARS-CoV-2 incidence we document here suggests that HCWs from quarantine hospitals may face a high occupational risk of infection, but that, with sufficient anticipation and infection control measures, this risk can be brought down to levels similar to those observed in standard healthcare settings. WHAT THIS PAPER ADDSO_ST_ABSWhat is already known on this topicC_ST_ABSPrevious studies conducted in standard care settings have documented that frontline healthcare workers (HCWs) face high risk of COVID-19. Whether risk levels differ in alternative care models, such as COVID-19 quarantine hospitals in Egypt where HCWs resided in the hospital days and nights for various durations, is unknown. What this study addsCOVID-19 risk for HCWs in quarantine hospitals varies substantially between facilities, from risk levels that are in the range of those documented in standard healthcare settings to levels that were approximatively 3 times higher. How this study might affect research, practice or policyWith sufficient anticipation and infection control measures, occupational COVID-19 risk for HCWs working in quarantine hospitals can be brought down to levels similar to those observed in standard healthcare settings.
