Molecular Crowding Modulates SARS-CoV-2 Aptamer Affinity

SARS-CoV-2 aptamer is a favorable candidate for the recognition and detection of SARS-CoV-2, owing to its small size and easy synthesis. However, the issue of compromised binding affinities in real samples and targeting mutant SARS-CoV-2 hinder wide applications of the aptamer. In this study, it is discovered that molecular crowding could increase binding affinity of CoV2-6C3 aptamer against RBD (Receptor Binding Domain) of SARS-CoV-2 via increasing the absolute value of the enthalpy change. The values of the equilibrium dissociation constant in molecular crowding decrease by 70% and 150%, respectively, against wild-type and mutant RBD compared with those in buffer without crowding. Moreover, the detection limit of SARS-CoV-2 pseudovirus is up to 5 times lower under molecular crowding compared to dilute conditions. The discovery deepens the understanding of aptamer-target interaction mechanisms in crowding conditions and provides an effective way to apply SARS-CoV-2 aptamer for virus recognition and detection.

Implementation of radiotherapy in a tertiary hospital in Zhejiang province during the epidemic of COVID-19.

Objective: To explore the clinical practice of delivering radiotherapy during the outbreak of 2019 novel coronavirus disease(COVID-19). Method(s): During this epidemic period, available method including but not limited to: strict disinfection, body temperature monitoring and staff training of relevant knowledge, were used to ensure the safety of radiotherapy treatment. Statistical analysis was performed to study the relevant data including proportion of patients receiving radiotherapy for different purposes, time from scanning to the first time of radiation delivery and degree of satisfaction in the view of staffs and patients, respectively. Result(s): A total of 60 patients received radiation therapy in the department of radiotherapy of Zhejiang Provincial People's Hospital (2020-02-11). Compared with the same period in 2019 (after the Spring Festival), the total number of patients receiving radiotherapy was decreased from 72 to 60(83.3%). Among them, the number of patients receiving palliative radiation therapy decreased significantly, while the proportion of radical, preoperative and/or postoperative radiotherapy/radiochemotherapy did not significantly decrease. There was significant difference between two years (chi2=6.967, P<0.05). The median time for newly admitted patients to receive radiotherapy was two days, which was not significantly longer than the interval in 2019 (P>0.05). Staff and patients were generally satisfied with the current prevention measures. Conclusion(s): Using a variety of prevention and control method, and taking full account of medical safety and patient benefits, radiation-related activities can be carried out during the epidemic.Copyright © 2020 by the Chinese Medical Association.

Cerebral venous thrombosis after ChAdOx1 nCoV-19 vaccination: a systematic review

OBJECTIVE: To perform a systematic review of case reports or case series regarding thrombosis with thrombocytopenia syndrome (TTS) and cerebral venous thrombosis (CVT) related to ChAdOx1 nCoV-19 vaccination to address the clinical features, laboratory findings, treatment modalities, and prognosis related with CVT. SUBJECTS AND METHODS: We included 64 TTS patients from 19 articles, 6 case series and 13 case reports, in which thrombosis occurred after the first dose of ChAdOx1 nCoV-19 vaccination published up to 30 June 2021 in Embase, ePubs, Medline/PubMed, Scopus, and Web of Science databases. RESULTS: Of the 64 TTS patients, 38 (59.3%) had CVT. Patients with CVT were younger (median 36.5 vs. 52.5 years, p<0.001), had lower fibrinogen levels (130 vs. 245 mg/dL, p=0.008), had more frequent history of intracerebral hemorrhage (ICH), and had higher mortality rate (48.6% vs. 19.2%, p=0.020) than that of patients without CVT. In multivariable analysis, the possibility of presence of CVT was higher in younger age groups [odd ratio (OR): 0.91, 95% confidence interval (CI): (0.86-0.97, p<0.001)] and those with accompanying intracerebral hemorrhage (ICH) (OR: 13.60, 95% CI (1.28-144.12, p=0.045). CONCLUSIONS: Our study demonstrated that CVT related to ChAdOx1 nCoV-19 vaccination was associated with younger age, low levels of fibrinogen, presence of ICH and more frequent mortality compared to those of non-CVT. If TTS occurs after ChAdOx1 nCoV-19 vaccination, the presence of CVT in patients with young age or ICH should be considered.

An immobilization-based, loop-mediated isothermal amplification device for nucleic acid detection of SARS-CoV-2 N gene

Confronting the global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), simple, fast and specific non-laboratory SARS-CoV-2 diagnostic tests are urgently required. However, the current nucleic acid assays generally rely on the diagnostic laboratory, trained staff and specialized equipment for execution and analysis, presenting clear limitations in the field detection. Here, we describe a portable and reliable immobilization-based loop-mediated isothermal amplification (LAMP) device which is mobile, without the requirement of any complicated instrument and appropriate for high-throughput testing. This device was constructed by utilizing the interaction between a carboxyl-tagged primer and an amino-tagged substrate, and capable of catching the target sequence in SARS-CoV-2 produced via the immobilization-based LAMP. In this study, the immobilization conditions and immobilized primer structure were explored and optimized. With this proposed device, the analysis result can be obtained rapidly in 30 min with excellent specificity, even if the template is extracted from a complex sample containing pharyngeal swab or human blood. In addition, the device can be applied to detect the nucleic acid of SARS-CoV-2 and various other pathogens, showing attractive potential for rapid and high-throughput detection at airports, railway stations, cold-chain transportations, community hospitals and so on. Therefore, we believe that the immobilization-based LAMP device is an advanced approach to developing a portable, specific, low-cost and high-throughput diagnostic platform.

Cerebral venous thrombosis after ChAdOx1 nCoV-19 vaccination: a systematic review.

OBJECTIVE: To perform a systematic review of case reports or case series regarding thrombosis with thrombocytopenia syndrome (TTS) and cerebral venous thrombosis (CVT) related to ChAdOx1 nCoV-19 vaccination to address the clinical features, laboratory findings, treatment modalities, and prognosis related with CVT. SUBJECTS AND METHODS: We included 64 TTS patients from 19 articles, 6 case series and 13 case reports, in which thrombosis occurred after the first dose of ChAdOx1 nCoV-19 vaccination published up to 30 June 2021 in Embase, ePubs, Medline/PubMed, Scopus, and Web of Science databases. RESULTS: Of the 64 TTS patients, 38 (59.3%) had CVT. Patients with CVT were younger (median 36.5 vs. 52.5 years, p<0.001), had lower fibrinogen levels (130 vs. 245 mg/dL, p=0.008), had more frequent history of intracerebral hemorrhage (ICH), and had higher mortality rate (48.6% vs. 19.2%, p=0.020) than that of patients without CVT. In multivariable analysis, the possibility of presence of CVT was higher in younger age groups [odd ratio (OR): 0.91, 95% confidence interval (CI): (0.86-0.97, p<0.001)] and those with accompanying intracerebral hemorrhage (ICH) (OR: 13.60, 95% CI (1.28-144.12, p=0.045). CONCLUSIONS: Our study demonstrated that CVT related to ChAdOx1 nCoV-19 vaccination was associated with younger age, low levels of fibrinogen, presence of ICH and more frequent mortality compared to those of non-CVT. If TTS occurs after ChAdOx1 nCoV-19 vaccination, the presence of CVT in patients with young age or ICH should be considered.

Early initiation of hemoadsorption reduces the need for organ support in critically ill COVID-19 patients on ECMO: A post-hoc analysis from the CytoSorb Therapy in COVID-19 (CTC) Registry

Objectives: Preliminary results of the CTC Registry on the first 52 patients showed survival of 69% at 90 days [1]. The current exploratory analysis aimed to examine whether the time of initiation of hemoadsorption (i.e.: early vs late) had any effect organ support requirements and survival. Method(s): We included all 100 patients recruited in the CTC Registry in 5 U.S. intensive care units (ICU). The median time from ICU admission to the start of hemoadsorption was 86.7 h. We created two post hoc groups: <=86.7 h (group-early, GE) and >86.7 h (group-late, GL) and compared outcomes with special focus on the need of mechanical ventilation (MV), vasopressor, renal replacement therapy (CRRT) and extracorporeal membrane oxygenation (ECMO). Result(s): There was no difference between groups in baseline characteristics. 90-day survival was 78% in GE and 62% in GL (p=0.08). Patients in the GL vs GE spent longer time on ECMO (p=0.021), mechanical ventilation (p=0.02) and needed significantly longer ICU-stay (p=0.002), (Fig. 1). There was also a trend for longer vasopressor support (8 [4-21] vs 4 [1-17] days, p=0.13). There was no significant difference between the groups regarding the need of CRRT. Conclusion(s): The current analysis shows that early initiation of hemoadsorption with ECMO in critically ill COVID-19 patients is associated with shorter duration of organ support measures and shorter ICU stays.

Comparison of Video-Coached Remote Spirometry with In-Person Spirometry in Patients with Severe Asthma Participating in the NHLBI PrecISE Network

Introduction: PrecISE is an ongoing Phase II clinical trial sponsored by the National Heart, Lung, and Blood Institute to investigate the efficacy of several treatments for severe asthma. The threat of COVID-19 has raised interest in obtaining reliable spirometry data for asthma research and clinical care in a remote, “no-touch” fashion. Prior studies of the accuracy of remote spirometry have not included real-time coaching. The PrecISE investigators hypothesized that remote spirometry with real-time video coaching could provide an accurate FEV1 for use as a study endpoint in a clinical trial setting. Methods: PrecISE network participants had remote spirometry post-bronchodilator (4 puffs of albuterol) measured with video coaching from trained research coordinators using the ZEPHYRx platform connected to MIR Spirobank Smart handheld spirometers. Remote spirometry measurements occurred within a +/- 3-day window from scheduled in-person PrecISE visits during which in-person spirometry with bronchodilator challenge was measured with standard equipment (Vyaire Medical). All measurements occurred during the screening/run-in period of the PrecISE protocol. Both remote and in-person spirometry was overread by the PrecISE Spirometry Core and only included in analysis if sessions met ATS acceptability and reproducibility criteria. Correlations between remote and in-person FEV1 and FVC were analyzed, and Bland-Altman plots generated. As a comparison, within subject biological variability was measured using data from separate in-person visits during the screening/run-in period. Results: A total of 128 pairs of remote/in-person spirometry data were obtained. The mean FEV1 for remote spirometry was 2.50 L (SD 0.81) and for inperson spirometry was 2.42 L (SD 0.80), with an estimated correlation of 0.95 (95% CI: 0.93, 0.97). The mean difference in FEV1 (in-person - remote) was -0.07 L (95% CI: -0.11, -0.03, SD 0.25). The mean FVC for remote spirometry was 3.72 L (SD 1.01) and for in-person spirometry was 3.53 L (SD 0.93), with an estimated correlation of 0.91 (95% CI: 0.87, 0.93). The mean difference in FVC (in-person - remote) was -0.19 L (95% CI: -0.27, -0.12, SD 0.42). A total of 142 pairs of repeated in-person spirometry measurements were performed (median time between measurements: 43 days), with mean difference in FEV1 of -0.01 L (95% CI: -0.06, 0.03) and FVC of -0.02 L (95% CI: -0.07, 0.03). Bland-Altman plots for FEV1 differences are shown in Figure 1. Conclusions: Remote spirometry with real-time video coaching provides a reliable FEV1 measurement which correlates closely with in-person spirometry and is suitable for use in clinical trials. (Figure Presented).

[Course of disease and related epidemiological parameters of COVID-19: a prospective study based on contact tracing cohort].

Objective: To analyze the course of disease and epidemiological parameters of COVID-19 and provide evidence for making prevention and control strategies. Methods: To display the distribution of course of disease of the infectors who had close contacts with COVID-19 cases from January 1 to March 15, 2020 in Guangdong Provincial, the models of Lognormal, Weibull and gamma distribution were applied. A descriptive analysis was conducted on the basic characteristics and epidemiological parameters of course of disease. Results: In total, 515 of 11 580 close contacts were infected, with an attack rate about 4.4%, including 449 confirmed cases and 66 asymptomatic cases. Lognormal distribution was fitting best for latent period, incubation period, pre-symptomatic infection period of confirmed cases and infection period of asymptomatic cases; Gamma distribution was fitting best for infectious period and clinical symptom period of confirmed cases; Weibull distribution was fitting best for latent period of asymptomatic cases. The latent period, incubation period, pre-symptomatic infection period, infectious period and clinical symptoms period of confirmed cases were 4.50 (95%CI:3.86-5.13) days, 5.12 (95%CI:4.63-5.62) days, 0.87 (95%CI:0.67-1.07) days, 11.89 (95%CI:9.81-13.98) days and 22.00 (95%CI:21.24-22.77) days, respectively. The latent period and infectious period of asymptomatic cases were 8.88 (95%CI:6.89-10.86) days and 6.18 (95%CI:1.89-10.47) days, respectively. Conclusion: The estimated course of COVID-19 and related epidemiological parameters are similar to the existing data.

Relationship of lung oxygenation to timing of hemoadsorption therapy initiation in COVID-19 patients requiring extracorporeal mechanical oxygenation (ECMO): an observational analysis from the CytoSorb therapy in COVID-19 (CTC) Registry

Introduction: The multicenter CTC Registry study collected patientlevel data in COVID-19 patients receiving CytoSorb therapy under FDA Emergency Use Authorization. An earlier report on the first 52 CTC patients on ECMO treated with CytoSorb showed 69% overall survival [1]. The current analysis focuses on changes in pulmonary function relative to the time of CytoSorb therapy. Methods: A total of 56 patients from 5 U.S. centers were included. Data on demographics, mechanical ventilation (MV), ECMO, and arterial blood gases during CytoSorb therapy were analyzed. Linear regression was used to evaluate the relationship between the timing of initiation of CytoSorb therapy to lung oxygenation according to changes in PaO2/FiO2 ratio. Results: In the current analysis, 71% (40/56) overall survival was observed. For these survivors, time to CytoSorb start after ICU admission, MV start, and ECMO start was 138 ± 171.3 h, 83 ± 111.0 h, and 55 ± 156.5 h, respectively, with mean duration of CytoSorb therapy of 83 ± 29.1 h. At the first 24 h following CytoSorb therapy, oxygenation was improved evidenced by decreased MV FiO2 and ECMO FdO2 requirements and an increased PaO2/FiO2 ratio (90.2 ± 58.13 mmHg to 166.3 ± 98.67 mmHg, p < 0.001, N = 21). Linear regression analysis suggested that earlier initiation of CytoSorb therapy following ICU admission may be correlated to greater improvements in PaO2/FiO2 ratio (r = -0.37, p = 0.103), however, this trend did not achieve statistical significance. Conclusions: High survival rates have been observed with adjunct CytoSorb therapy in critically ill COVID-19 patients on ECMO. The current analysis suggests that early initiation of hemoadsorption following ICU admission may contribute to earlier improvements in native lung oxygenation.

Mortality, risk factors, and treatment of COVID-19 infection in solid organ transplants: A systematic review and meta-analysis

Purpose: Outcomes for solid organ transplants (SOT) with COVID-19 have not been summarized, and prognostic factors for COVID-19 in SOT patients are not well established yet. Methods: We searched PubMed, EMBASE, and Cochrane library up to November 10, 2020, to identify reports of SOT patients and COVID-19. This study was performed to estimate the risk of death and other important outcomes. Further, we also evaluated the risk factors associated with mortality and severe COVID-19 infection in SOT patients. Pooled prevalence, odds ratios (OR), and 95% confidence intervals (CI) were calculated using a random-effects model. Results: Fifty-nine studies involving 7071 SOT patients were included. 22% of SOT patients with COVID-19 were dead (20%-25%), 48% had acute kidney injury, 39% developed severe infection, 28% needed intensive care unit (ICU) admission, 35% had acute respiratory distress syndrome, and 23% needed invasive ventilation. Univariate analysis revealed that advanced age (OR=3.01, OR=2.97), obesity (OR=1.44, OR=2.05) and diabetes (OR=2.00, OR=1.73) were associated with severe infection and mortality. Laboratory abnormalities at admission including higher C reaction protein, D-Dimer, lactate dehydrogenase, procalcitonin, and lower lymphocyte also increased the risk of death. Initial MMF use (OR=1.61) contributed to severe infection, and tacrolimus (OR=1.70) led to more deaths. Further, calcinurin inhibitors withdrawal (OR=2.62), high dose steroids (OR=2.46), Tocilizumab (OR=1.75), ICU admission (OR=5.00), and invasive ventilation (OR=7.56) were associated with mortality. Conclusions: Our study demonstrated that SOT patients with COVID-19 had a high mortality and risk factors identification may contribute to patients stratification and management.

Repositioning Molecules of Chinese Medicine to Targets of SARS-Cov-2 by Deep Learning Method

Traditional Chinese medicine has been used to treat and prevent infectious diseases for thousands of years, and has accumulated a large number of effective prescriptions. Deep learning methods provide powerful applications in calculating interactions between drugs and targets. In this study, we try to use the method of deep learning to reposition molecules of Chinese medicines (CMs) and the targets of syndrome coronavirus 2 (SARS-CoV-2). A deep convolution neural network with residual module (DCNN-Res) is constructed and trained on KIBA dataset. The accuracy of predicting the binding affinity of drug-target pairs is 85.33%. By ranking binding affinity scores of 433 molecules in 35 CMs to 6 targets of SARS-Cov-2, DCNN-Res recommends 30 possible repositioning molecules. The consistency between our result and the latest research is 0.827. The molecules in Gancao and Huangqin have a strong binding affinity to targets of SARS-CoV-2, which is also consistent with the latest research.

What convalescent plasma in treating severe acute respiratory infections of viral aetiology can hint for COVID-19? Evidence from a meta-analysis.

OBJECTIVE: To explore whether convalescent plasma therapy is beneficial to patients with severe acute respiratory infections and gave hints to the management of COVID-19. METHODS: A comprehensive literature search of PubMed, Web of Science, Embase, and Cochrane library was conducted for all eligible studies range from inception to February 29, 2020. Studies with control group were included. Treatment group received convalescent plasma therapy, and control group may receive any therapy other than convalescent plasma therapy. Odds ratios (ORs), mean differences (MDs) and 95% confidence intervals (CIs) were pooled for categorical and continuous outcomes. RESULTS: A total of 1997 patients from 13 studies were included, and seven studies were prospectively designed. Pooled analysis indicated convalescent plasma treatment significantly reduced the mortality by 51% (OR=0.49, 95% CI: 0.36 to 0.67). Subgroup analyses by publication time, study design, and influenza A revealed similar results. Sensitivity analyses suggested that the results were stable. In addition, convalescent plasma therapy reduced mechanical ventilation requirement (OR: 0.35, 95% CI: 0.21 to 0.59), while it was not associated with less use of extracorporeal membrane oxygenation (OR: 2.0, 95% CI: 0.83 to 4.83) and shorter length of hospital stay (MD: -2.20, 95% CI: -4.98 to 0.57days). Pooled estimates showed there was no difference in serious adverse effects between the convalescent plasma treatment and control groups (OR: 0.75, 95% CI: 0.50 to 1.13). CONCLUSION: Convalescent plasma therapy significantly reduced the mortality and mechanical ventilation requirements of patients with virus-induced severe acute respiratory infections, without serious adverse effects. More studies are needed to explore whether this treatment can be extrapolated into COVID-19.

Report of the 2020 Organ Care System Workforce Survey: Personnel Profiles and Staffing Models

Purpose One of the most significant challenges to establishing or maintaining a viable transplant program that utilizes the TransMedics Organ Care System (OCS) (TransMedics, Andover, MA) is ensuring adequate staffing resources. There is no published literature on which health professionals should primarily operate OCS platforms. Therefore, a valid survey is needed to document the current workforce involvement and anticipate the future demands of this evolving technology. Methods As of July 2020, 35 institutions in the United States had active OCS capabilities. A web-based survey presented 38 different survey questions covering general topics about staffing, compensation structure, institutions' challenges, the impact of COVID-19, and specific questions to each platform. This survey aims to present the healthcare community with an accurate workforce representation of the professionals who primarily operate the OCS platforms. Results Of the 35 OCS institutions, 100% responded to the survey. 52 OCS platforms are utilized, including heart (n=19), liver (n=17), and lung (n=16). 37.1% operate multiple platforms. Institutions had 2 to 25 total OCS-trained staff with a median of 10 trained staff. Across all platforms, perfusionists and doctors were the most common primary operators (Fig 1). Challenges to adequately staffing OCS transports (Fig 2,3) included the reluctance of staff to participate (65.7%), administrative or financial hurdles (60%), and insufficient staffing (57.1%). Major reasons for staff reluctance to participate in OCS transports (Fig 2) included lack of incentive (39.1%) and transport duration (47.8%). 45.7% of institutions offered additional compensation for OCS operators going out on a run. Conclusion This survey provides vital statistics of current staffing models and highlights limitations. As this revolutionary technology continues to transform transplantation, these findings should guide institutions in preparing rational plans to address the workforce's future needs.

[Analysis on the cluster epidemic of coronavirus disease 2019 in Guangdong Province].

Objective: Analysis of clustering characteristics of coronavirus disease 2019 (COVID-19) in Guangdong Province. Methods: The COVID-19 cases in Guangdong Province onset from January 1 to February 29, 2020 were collected from Chinese information system for disease control and prevention and Emergency Public Reporting System. Obtain the epidemiological survey data of the cluster epidemic situation, and clarify the scale of cluster epidemic situation, the characteristics of the index cases, family and non-family subsequent cases. Calculate serial interval according to the onset time of the index cases and subsequent cases, secondary attack rate based on the close contacts tracking results, the characteristics of different cases in the clustered epidemic were compared. Results: A total of 283 cluster were collected, including 633 index cases, 239 subsequent cases. Families are mainly clustered, the total number involved in each cluster is in the range of 2-27, M (P25, P75) are 2.0 (2.0, 4.0). During January 15 to February 29, the secondary attack rate is 2.86% (239/8 363) in Guangdong Province, the family secondary attack rate was 4.84% (276/3 697), and the non-family secondary attack rate was 1.32% (61/4 632). According to the reporting trend of the number of cases in Guangdong Province, it can be divided into four stages, the rising stage, the high platform stage, the descending stage and the low level fluctuation period. The secondary attack rate of the four stages were 3.5% (140/3 987), 2.3% (55/2 399), 2.6% (37/1 435), 1.3% (7/542), respectively. The difference was statistically significant (P=0.003). Conclusion: COVID-19 cluster mainly occurs in families in Guangdong Province. The scale of the clustered epidemic was small; the serial interval was short; and the overall secondary attack rate was low.

[Risk assessment and early warning of imported COVID-19 in Guangdong province].

Objective: To assess the imported risk of COVID-19 in Guangdong province and its cities, and conduct early warning. Methods: Data of reported COVID-19 cases and Baidu Migration Index of 21 cities in Guangdong province and other provinces of China as of February 25, 2020 were collected. The imported risk index of each city in Guangdong province were calculated, and then correlation analysis was performed between reported cases and the imported risk index to identify lag time. Finally, we classified the early warming levels of epidemic by imported risk index. Results: A total of 1 347 confirmed cases were reported in Guangdong province, and 90.0% of the cases were clustered in the Pearl River Delta region. The average daily imported risk index of Guangdong was 44.03. Among the imported risk sources of each city, the highest risk of almost all cities came from Hubei province, except for Zhanjiang from Hainan province. In addition, the neighboring provinces of Guangdong province also had a greater impact. The correlation between the imported risk index with a lag of 4 days and the daily reported cases was the strongest (correlation coefficient: 0.73). The early warning base on cumulative 4-day risk of each city showed that Dongguan, Shenzhen, Zhongshan, Guangzhou, Foshan and Huizhou have high imported risks in the next 4 days, with imported risk indexes of 38.85, 21.59, 11.67, 11.25, 6.19 and 5.92, and the highest risk still comes from Hubei province. Conclusions: Cities with a large number of migrants in Guangdong province have a higher risk of import. Hubei province and neighboring provinces in Guangdong province are the main source of the imported risk. Each city must strengthen the health management of migrants in high-risk provinces and reduce the imported risk of Guangdong province.

[Clinical outcomes of COVID-19 cases and influencing factors in Guangdong province].

Objective: To analyze the clinical courses and outcomes of COVID-19 cases and the influencing factors in Guangdong province and provide basis for the formulation or adjustment of medical care and epidemic control strategy for COVID-19. Methods: We collected demographic data, medical histories, clinical courses and outcomes of 1 350 COVID-19 patients reported in Guangdong as of 4 March 2020 via epidemiological investigation and process tracking. Disease severity and clinical course characteristics of the patients and influencing factors of severe illness were analyzed in our study. Results: Among 1 350 cases of COVID-19 cases in Guangdong, 72 (5.3%) and 1 049 (77.7%) were mild and ordinary cases, 164 (12.1%) were severe cases, 58 (4.3%) were critical cases and 7 (0.5%) were fatal. The median duration of illness were 23 days (P(25), P(75): 18, 31 days) and the median length of hospitalization were 20 days (P(25), P(75): 15,27 days). For severe cases, the median time of showing severe manifestations was on the 12(th) day after onset (P(25), P(75): 9(th) to 15(th) days), and the median time of severe manifestation lasted for 8 days (P(25), P(75): 4, 14 days). Among 1 066 discharged/fetal cases, 36.4% (36/99) and 1.0% (1/99) of the mild cases developed to ordinary cases and severe cases respectively after admission; and 5.2% (50/968) and 0.6% (6/968) of the ordinary cases developed to severe cases, and critical cases respectively after admission. In severe cases, 11.4% developed to critical cases (10/88). The influencing factors for severe illness or worse included male (aHR=1.87, 95%CI: 1.43-2.46), older age (aHR=1.67, 95%CI: 1.51-1.85), seeking medical care on day 2-3 after onset (aHR=1.73, 95%CI: 1.20-2.50) pre-existing diabetes (aHR=1.75, 95%CI: 1.12-2.73) and hypertension (aHR=1.49, 95%CI: 1.06-2.09). Conclusions: The course of illness and length of hospitalization of COVID-19 cases were generally long and associated with severity of disease clinical outcomes. The severe cases were mainly occurred in populations at high risk. In the epidemic period, classified management of COVID-19 cases should be promoted according to needs for control and prevention of isolation and treatment for the purpose of rational allocation of medical resources.