Predictors of severe symptomatic laboratory-confirmed SARS-COV-2 reinfection

Murillo-Zamora, Efrén; Mendoza-Cano, Oliver; Delgado-Enciso, Iván; Hernandez-Suarez, Carlos M.

Objective To evaluate factors predicting severe symptomatic laboratory-confirmed (reverse transcription-quantitative polymerase chain reaction, RT-qPCR) SARS-COV-2 (severe acute coronavirus-2) reinfection. Study design A nationwide retrospective cohort study was conducted in Mexico. Method Data from 258 reinfection cases (at least 28 days between both episodes onset) were analyzed. We used risk ratios (RR) and 95% confidence intervals (CI) to evaluate predictors of severe (dyspnea requiring hospital admission) secondary SARS-COV-2 infection. Results The risk of severe disease was 14.7% and the observed overall fatality rate was 4.3%. Patients with more serious primary disease were more likely to develop severe symptoms (39.5% vs. 5.5%, p < 0.001) during reinfection. In multiple analysis, factors associated with an increased risk of severe symptomatic SARS-COV-2 reinfection were increasing age (RR per year = 1.007, 95% CI 1.003-1.010), comorbidities (namely obesity [RR = 1.12, 95% CI 1.01-1.24], asthma [RR = 1.26, 95% CI 1.06-1.50], type 2 diabetes mellitus [RR = 1.22, 95% CI 1.07 - 1.38] and previous severe laboratory-confirmed COVID-19 (RR = 1.20, 95% CI 1.03-1.39). Conclusions To the best of our knowledge this is the first study evaluating disease outcomes in a large set of laboratory-positive cases of symptomatic SARS-COV-2 reinfection and factors associated with illness severity was characterized. Our results may contribute to the current knowledge of SARS-COV-2 pathogenicity and to identify populations at increased risk of a poorer outcome after reinfection.