Abstract:
Objective To analyze the epidemiological characteristics and influencing factors of SARS-CoV-2 reinfection by conducting follow-up investigations among community residents who experienced their first SARS-CoV-2 infection between March and June 2022, so as to provide a scientific basis for predicting future epidemic trends and adjusting prevention and control strategies.
Methods A cohort study was conducted in Xuhui District, Shanghai. A total of 1 208 individuals with a documented primary SARS-CoV-2 infection between March and June 2022 were enrolled and followed-up longitudinally. Data were collected using structured questionnaire surveys to assess the reinfection rate, incidence density, and clinical manifestations of SARS-CoV-2 reinfection. A logistic regression model was used to analyze the influencing factors of SARS-CoV-2 reinfection.
Results A total of 497 SARS-CoV-2 reinfection cases were observed among the 1 208 research subjects, with a reinfection rate of 41.14% and an incidence density of 0.63 cases per 1 000 person-days. The cumulative reinfection rates at 6, 9, 12, 15, and 18 months following the initial infection were 0.08%, 15.31%, 19.04%, 33.53%, and 38.25%, respectively. Compared with the primary infection, reinfection was more likely to be symptomatic, with a greater severity of fever, dry cough, sore throat, and runny nose. Being female, younger age, and symptom duration ≥7 days during the primary infection were identified as influencing factors for SARS-CoV-2 reinfection, while a higher socioeconomic status can reduce the risk of SARS-CoV-2 reinfection.
Conclusion SARS-CoV-2 reinfection is relatively common and often symptomatic. Age, gender, income level, and the duration of symptoms during the primary infection are identified as infuencing factors for SARS-CoV-2 reinfection. Continuous monitoring of reinfection in the population is recommended, along with the development of effective strategies to mitigate the impact of reinfection.