Positive RT-PCR Test Results in Discharged COVID-19 Patients: Reinfection or Residual? (preprint)

Background: The coronavirus disease-19 (COVID-19) is a highly infectious disease. Moreover, 14% of the discharged patients tested virus positive again. However, the underlying clinical mechanisms are still under investigation. Case presentation: The current study summarized the clinical course, radiological features and laboratory test results of two COVID-19 patients who tested positive again during the quarantine after hospital discharge. We found that while all symptoms were relieved, their lesions in lungs were not fully recovered, and both of them had slight coughs. In addition, when the lesions were further recovered and the cough symptoms were further remitted, they tested virus negative again. Conclusions: These results implied that the positive result is unlikely caused by the reinfection from others or the remained virus. Rather, it may derive from the remained virus transferred from the lower respiratory tract to the throat or nose with coughs. Accordingly, we proposed some suggestions regarding the discharge management. This study enhances our knowledge of the progress of COVID-19 and benefit the control of this disease.

Correlation analysis between CT findings and duration of initial symptoms in young and middle-aged patients with novel coronavirus pneumonia (preprint)

Objective: To retrospectively analyze the correlation between CT findings and duration of initial symptoms in young and middle-aged patients with novel coronavirus pneumonia.Materials and methods: From January 17, 2020 to February 4, 2020, of the 54 SARS-COV-2 infection cases, 48 cases (48/54,88.8%) were young and middle-aged patients under 60 years old. Finally, thirty-three patients under 60 years old with CT imaging were enrolled in this study, including 20 men and 13 women. Patients’ clinical data, including gender, age, infection exposure history, heating temperature, the initial symptoms and the duration, were recorded. The CT imaging features of pneumonia was scored. The number of lung lobe involvement and the length of the largest lesion were recorded. All above CT findings and clinical data were evaluated.Results: The median duration of initial symptoms was 3 days (range 0-7 days). The CT score and the length of the largest lesion showed statistically significant between the groups of initial symptom duration < 3 days and initial symptom duration ≥3 days (P<0.05). while age, gender, infection exposure history, fever temperature and the number of affected pulmonary lobes between the two groups had no significant difference (P>0.05). The duration of the initial symptom was positively correlated with both the CT score of pneumonia (r=0.502, P=0.003) and the length of the largest pneumonia lesion in the lung (r=0.506, P=0.003).Conclusion: The severity of pneumonia and the size of lesions were positively correlated with the duration of the initial symptom in young and middle-aged patients.