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.

Background: Around the globe, moderate cases account for the largest proportion of all coronavirus disease 2019 (COVID-19) patients, and deteriorated moderate patients contribute the most in mortality. However, published articles failed to address the deterioration details of moderate cases, especially on when and how they deteriorated.Methods: All moderate COVID-19 patients hospitalized in Guangdong Province from January 14 to March 16, 2020, were included in this multicenter retrospective cohort study and were divided into deteriorated and non-deteriorated groups according to clinical status. Symptoms and demographic, therapeutic, and laboratory test result characteristics were collected to explore the features of disease deterioration.Results: Of 1,168 moderate patients included, 148 (13%) deteriorated to severe (130 cases) or critical (18 cases) status. Over 20% of the older subgroup (>50 years old) showed deterioration. The median time for deterioration was 11 days after onset [interquartile range (IQR) 9–14 days]. In addition, 12.2% severe cases could further develop to critical status after 3 days (IQR 2–6.5 days) of having a severe condition. Respiratory dysfunction and hypoxia were the major manifestations as disease deterioration, while 76 cases (52.1%) showed respiratory rate >30 breaths/min, 119 cases (80.4%) showed SaO2 <93%, 100 cases (67.5%) had 201 < PaO2/FiO2 < 300, and 27 cases (18.9%) had blood lactic acid >2.0 mmol/L. In view of multiple organ dysfunction, 87.8% of acute respiratory distress syndrome (ARDS), 20.2% of acute kidney injury (AKI), 6.8% of coagulopathy, 4% of acute heart failure (AHF), 3.4% of acute hepatic injury (AHI), and 5.4% of shock occurred in deteriorated patients, while organ injury occurred in the following sequence: ARDS, AKI, AHF, coagulopathy, AHI, and shock.Conclusions: The deteriorated pattern of moderate COVID-19 patients is characterized as the 11th day from onset (IQR 9–14 days) being an important time point of disease deterioration with further exacerbation to critical condition in 3 days (IQR 2–6.5 days), A RDS followed by AKI being the typical modes of sequential organ damage.