Epidemiological and clinical findings of short-term recurrence of SARS-CoV-2 RNA PCR positivity in 1282 discharged COVID-19 cases: a multi-center, retrospective, observational study

Chen, Sheng-long; Xu, Hui; Feng, Hui-ying; Sun, Jiu-feng; Li, Xin; Zhou, Lin; Song, Wen-liang; Huang, Shan-shan; He, Jun-lei; Deng, Yi-yu; Wang, Rui-jie; Fang, Ming

BACKGROUND: Short-term recurrence of positive SARS-CoV-2 RNA PCR in discharged COVID-19 patients attracts the public’s concern. This study aimed to determine clinical and epidemiological results of such patients. METHODS: This retrospective study was conducted on 32 designated hospitals for COVID-19 patients discharged from January 14 (th) to March 10 (th), 2020. After 28-day followed-up, re-positive patients confirmed by SARS-CoV-2 RNA RT-PCR were re-admitted to hospital for further treatments. All the close contacts of re-positive patients were asked 14-day self-segregating. Data of epidemiology, symptoms, laboratory tests and treatments were analyzed in re-positive patients and their close contacts were investigated. RESULTS: Of 1,282 discharged patients, 189 (14.74%) were tested re-positive of SARS-CoV-2 RNA during 28-day follow-up. The median time from discharge to re-positivity was 8 days (IQR 5-13). Patients in re-positive group were younger (34yr vs 45yr, p&0.001) with higher proportion of moderate symptoms (95.77% vs 84.35%, p&0.001) in the first hospitalization than negative group. During the second hospitalization, all re-positive patients showed normal in peripheral white blood cell and lymphocyte, and no new symptoms of COVID-19; 78.31% further improved on chest CT scan compared with the first discharge, yet 25.93% accepted antiviral therapy. The median time of re-positive to negative was 8 days (IQR 4-15). None of close contacts developed COVID-19. CONCLUSIONS: Our data suggested that the short term recurrence of positive SARS-CoV-2 RNA in discharged patients is not a relapse of COVID-19, and the risk of onward transmission is very low. This provides important information for managing COVID-19 patients.