Clinical Characteristics of COVID-19 Reinfection: A Retrospective Study in China

Purpose The number of patients with COVID-19 reinfection is gradually increasing.In this study, we aimed to investigate the clinical characteristics of individuals who experienced COVID-19 reinfection. Methods A retrospective data analysis was conducted involving patients diagnosed with COVID-19 between April 1, 2023, and June 20, 2023. The patients were categorized into two groups: the observation group, consisting of individuals with reinfection, and the control group, comprising those with primary infection. Results A Total 905(905/1025) patients were included in the study,with 407 in the observation group and 498 in the control group. The top three clinical symptoms in both groups were fever, cough with expectoration, and dizziness with fatigue ( p  < 0.001). The clinical classification of patients in the observation group primarily consisted of non-severe cases, ( p <0.001). The proportion of hospitalized patients was lower in the observation group than in the control group ( p  < 0.001). The observation group exhibited a shorter clinical symptom recovery time than that of the control group (median, 5 d vs. 7 d, p  < 0.001). Conclusion Patients experiencing COVID-19 reinfection were primarily classified as non-severe cases, with lower proportions of occurrence of severe and rare critical conditions. The severity was milder compared to that in patients with primary COVID-19 infections.