Nested case-control study of health workers exposed to confirmed COVID-19 patients Similar objectives to the cohort study but case-control studies may be cheaper and provide robust evidence to characterize and assess the risk factors for SARS-CoV-2 infection in health workers exposed to COVID-19 patients Health workers with confirmed COVID-19 will be recruited as cases and other health workers in the same health care setting without infection will be recruited as controls (incidence density sampling) Secondary objectives are similar to the cohort study WHO is coordinating an international multi-centre study that will undoubtedly lead to a more robust analysis of potential factors affecting the secondary infection risk, and to a more detailed characterization of serological responses following infection A Go Data data collection template is available upon request
Assessment of risk factors for coronavirus disease 2019 (COVID-19) in health workers: protocol for a case-control study