Clinical Characteristics of the Discharged COVID 19 Patients with Re Positive Nucleic Acid Test

Background: There were cases recovered and discharged from Coronavirus Disease 2019 (COVID-19) who tested re-positive nucleic acid test for Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in the follow-up clinics. However, the clinical characteristics, and potential causes of this phenomenon still cannot be identified. Methods: Patients confirmed SARS-CoV-2 infection and first admitted to Wuhan Pulmonary Hospital, Hubei Province, China and then discharged from January17 to March 30, 2020 were under follow-up. Patients with hospital stay≥30 days were assigned to long-course group (LC group). Once the follow-up SARS-CoV-2 nucleic acid test became re-positive before April 27, 2020, the patients were involved in re-positive group (RP group). Meanwhile, we matched another group of patients (Matched group) to the RP group at 1:1, according to the admission time (three days before or after). Baseline features, clinical symptoms, laboratory tests, Computed Tomography (CT) manifestations, comorbidities, and outcomes in the three groups were collected, summarized and analyzed. Findings: A total of 365 confirmed COVID-19 patients discharged from January17 to March 30, 2020, among which 31 patients presented re-positive SARS-CoV-2 nucleic acid test. The mean age of the RP group was 56·35±14·41(24-85) years, with 14(45·16%) patients older than 60 years. There was no obvious difference of age between RP group and LC group. Gender of 21(67·74%) RP patients were female, while significantly less in LC group (6(31·58%), p=0·014). The mean time from onset to admission was significant longer than LC group (17·6 vs 9·12, p= 0·006). The RP group displayed a milder clinical course. In regard to laboratory tests, neutrophil-to-lymphocyte ratio, c-reaction protein, CK-MBactivity, blood urea nitrogen (BUN), lactate dehydrogenase, hematocrit, and glucose were lower in RP group than in LC group. Cardiovascular disease and drinking were significant different between RP group and Matched group. Compared to the Matched group, shortness of breath and weight loss were more common in RP group. Interpretation: Compared to LC group, RP patients displayed milder clinical course no matter in the clinical manifestation or in the laboratory tests. RP patients should not be simply considered as a subtype of long course. Systemic symptom was more common, other than upper respiratory symptoms in RP patients than in the Matched group. Funding: Zhejiang University special scientific research fund, China Hospital Administer Research Institute, Shanghai Jiaotong University, and Shanghai Science and Technology Commission Fund. Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: This study was approved by the Ethics Committee of Xin Hua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (Approval No. XHEC-D-2020-100), which waived the requirement for written patient consent for this retrospective analysis. All patients gave their oral consent to participate in this retrospective study.