key: cord-0727342-9hstiu5x authors: Wu, X.; Wang, Z.; He, Z.; Li, Y.; Wu, Y.; Wang, H.; Liu, Y.; Hao, F.; Tian, H. title: A follow-up study shows no new infections caused by patients with repeat positive of COVID-19 in Wuhan date: 2020-11-22 journal: nan DOI: 10.1101/2020.11.18.20232892 sha: 4bd70797d4096b9cb80183f0f3f19f7448af2950 doc_id: 727342 cord_uid: 9hstiu5x Background: It has been reported that a few recovered COVID-19 patients could suffer repeat positive, testing positive for the SARS-CoV-2 virus again after they were discharged from hospital. Understanding the epidemiological characteristics of patients with repeat positive is vital in preventing a second wave of COVID-19. Methods: In this study, the epidemiological and clinical features for 20,280 COVID-19 patients from multiple centers between 31 December 2019 and 4 August 2020 in Wuhan were collected and followed. In addition, the RT-qPCR testing results for 4,079 individuals who had close contact with the patients suffering repeat positive were also obtained. Results: 2,466 (12.16%) of 20,280 patients presented with a repeat positive of SARS-CoV-2 after they were discharged from hospital. 4,079 individuals had close contact with them. The PCR result were negative for the 4,079 individuals. Conclusions: By a follow-up study in Wuhan, we show the basic characteristics of patients with repeat positive and no new infections caused by patients with repeat positive of COVID-19. preventing a second wave of COVID-19. The COVID-19 outbreak was first reported in Wuhan (5) and had lasted more than 3 months by 5 April 2020, after which date there were no further locally acquired infections. During the outbreak in Wuhan, there were a total of 50333 confirmed COVID-19 cases with 3869 deaths, and 46464 patients have been clinically cured and discharged according to WHO guidelines(6). After being discharged from hospital, patients in Wuhan continue to be isolated in rehabilitation center for 14 days and at home for another 14 days to prevent reinfection, followed up and then regularly revisited at hospitals. Here we collect all the information on SARS-CoV-2 patients with repeat positive between 31 December 2019 and 4 August 2020 across 84 hospitals in Wuhan, presenting epidemiological and clinical features. Cases of COVID-19 was diagnosed and the illness severity was defined according to the Chinese management guideline for COVID-19 (the sixth edition) published by National Health Commission of the People's Republic of China. All first diagnosis cases of COVID-19 were confirmed according to positive respiratory RT-PCR tests. Repeat positive were confirmed by digestive (anal swab) and respiratory positive RT-PCR tests. Samples by Nasopharyngeal swab or Pharynx swab were collected and tested for SARS-CoV-2, following WHO guidelines. The discharge criteria of the recovered patients included: body temperature is back to normal for more than . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) preprint The copyright holder for this this version posted November 22, 2020. ; https://doi.org/10.1101/2020.11.18.20232892 doi: medRxiv preprint three days, respiratory symptoms improve obviously, pulmonary imaging shows obvious absorption of inflammation, and nucleic acid tests negative for respiratory tract pathogen twice consecutively (sampling interval being at least 24 hours). Those who meet the above criteria can be discharged. After discharge, it is recommended for the patients to continue 14 days of isolation management and health monitoring, wear a mask, live in a single room with good ventilation. The patients are required to return to the hospitals for follow-up and revisit in two and four weeks after discharge. In this study, categorical variables were presented as numbers and percentages, and continuous variables were presented using median (interquartile range, IQR). Student t-test was used to compare continuous variables in two groups. Multivariate logistic regression model was used to determine the associated factors. All statistical analyses were performed using R version 3.4.1. P value less than 0.05 was considered statistically significant. In total, 20,280 patients were collected and followed. Among them, 2,466(12.16%) patients presented with a repeat positive of SARS-CoV-2 after they were discharged from hospital. The demographic and epidemiological characteristics of the these patients are similar to the first infections (shown in Table 1 ). Although several studies have reported patients with repeat positive of COVID-19, most are based on a limited sample and the proportion of SARS-CoV-2 reactivation ranged from 9% (5/55)(2) to 14.5% (38/262)(4). This study retrospectively analyzed clinical data in a cohort of 20,280 patients in Wuhan. We confirmed that in 12.16% of COVID-19 patients, SARS-CoV-2 could be isolated again after discharge from hospital. The time from SARS-CoV-2 negative to positive ranged from 1 to 165 days, suggesting that recovered patients still may be virus carriers and require additional round of viral detection and isolation. Note that the repeat positive could also be the virus fragment coming from the first infection because the PCR test only detects the fragments of SARS-CoV-2 genome, not viable virus. Another study shown that no infectious strain could be obtained by culture and no full-length viral genomes could be sequenced from 87 re-positive cases(7). These may explain why there were no secondary infection. Although this study does not completely exclude the possibility of reinfection, however, given the 28-day isolation and 84.07% (2058/2448) of the repeat positive occurred during this isolation in Wuhan, most of these patients have apparently not caused new infections after discharge from hospital in Wuhan. In this follow-up study in Wuhan, we show the basic characteristics of patients with repeat positive and no . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. Patient with repeat positive: the patient was test positive for SARS-CoV-2 again after being discharged from hospital. Treatment time: time interval of a patient being hospitalized. Close contact: the individuals living in the same houses with the patients. The epidemiological and clinical data collection was exempt from Institutional Review Boards, because it was part of public health investigation for COVID-19, issued by the National Health Commission of the People's Republic of China (http://www.nhc.gov.cn/jkj/s3577/202003/4856d5b0458141fa9f376853224d41d7.shtml). This study was approved by the Institutional Review Boards from Wuhan Center for Disease Control and Prevention. Not applicable. The data supporting the findings of this study are available within the article. . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. 1 650 cases were removed due to lack of detailed information 2 18 cases were removed due to lack of detailed information 3 4447 cases were removed due to lack of detailed information 4 1841 cases were removed due to lack of detailed information 5 5097 cases were removed due to lack of detailed information *10 cases were removed due to lack of detailed information . CC-BY 4.0 International license It is made available under a is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. (which was not certified by peer review) preprint The copyright holder for this this version posted November 22, 2020. ; https://doi.org/10.1101/2020.11.18.20232892 doi: medRxiv preprint An interactive web-based dashboard to track COVID-19 in real time The Lancet Infectious Diseases Positive RT-PCR Test Results in Patients Recovered from COVID-19 Clinical characteristics of the recovered COVID-19 patients with re-detectable positive RNA test An investigation of transmission control measures during the first 50 days of the COVID-19 epidemic in China We thank the many thousands of CDC staff and local health workers in China who collected data.