Difference of clinical characteristics in patients with reinfection and primary infection variants of SARS-CoV-2: a retrospective study in China.

BACKGROUND

The number of patients experiencing re-infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is progressively increasing. In this study, we aimed to explore the differences in clinical characteristics between patients with primary infection and those with re-infection of SARS-CoV-2.

METHODS

A retrospective data analysis was conducted involving patients diagnosed with coronavirus disease 2019 between April 1, 2023, and June 20, 2023. The patients were categorized into two groups: the observation group, consisting of individuals re-infected with SARS-CoV-2, and the control group, comprising those with primary SARS-CoV-2 infection.

RESULTS

A total of 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 did the control group (median, 5 days vs. 7 days, Log rank p<0.001, HR = 1.907(95% CI 1.669-2.178).

CONCLUSIONS

Patients experiencing SARS-CoV-2 re-infection 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 SARS-CoV-2 infection.