BMC Infect Dis. 2021 Sep 6;21(1):923. doi: 10.1186/s12879-021-06643-1.
BACKGROUND: Knowledge regarding factors predicting the SARS-COV-2 reinfection risk is scarce and it has major implications in public health policies. We aimed to identify factors associated with the risk of symptomatic SARS-COV-2 reinfection.
METHODS: We conducted a nationwide retrospective cohort study and 99,993 confirmed cases of COVID-19 were analyzed.
RESULTS: The overall risk of reinfection (28 or more elapsed days between both episodes onset) was 0.21% (incidence density, 2.5 reinfections per 100,000 person-days) and older subjects and those with the mild primary disease were at reduced risk of the event. Healthcare workers and immunosuppressed or renal patients had at greater risk of SARS-COV-2 reinfection.
CONCLUSIONS: If replicated in other populations, these results may be useful to prioritize efforts focusing on the reduction of SARS-COV-2 spread and the related burden.