Clinical course and characteristics of Corona Virus Disease 2019 in Xiaoshan, Hangzhou: A Retrospective study

Background: The World Health Organization declared the outbreak a public health emergency of international concern (Corona Virus Disease 2019) on January 30th, this study aimed to investigate the epidemiological and clinical characteristics of Corona Virus Disease 2019 in Xiaoshan, Hangzhou, and evaluate scientific basis for disease control and prevention. Methods: A total of 30 patients had been admitted to hospital from Jan 22 to Feb 22, 2020, all of them were laboratory confirmed SARS-Cov-2. Demographic, epidemiological, clinical, laboratory data were collected from Hospital information system and Epidemiological investigation reports. All data was performed by descriptive analysis, Chi-square test or non-parametric Mann-Whitney U test, as appropriate. Two sided p value less than 0.05 was considered statistically significant. Results: 30 patients were enrolled, the median age was 44.5 years (IQR 33.8-52.3) and 17 (56.7%) patients were female, 14 (46.7%) patients were native and had no exposure to Hubei Province. At the time of study submission, only one patient had not been discharged and no patients died during the study. The median hospital stay was 16.0 days (IQR 12.5-20.5) and the median course of disease was 20.5 days (IQR 17.0-23.3). The most common symptoms were fever (66.7%), dry cough (26.7%), and pharyngalgia (23.3%) on first admission. Most patients were generally illness or more mild, but 10 (33.3%) patients received oxygen therapy and 14 (46.7%) patients received hormone therapy during their hospitalization. Almost half of patients showed mild lymphocytopenia and 40% patients had elevated concentrations of CRP in the early stages of COVID-19. Conclusions: Among the 30 patients were confirmed with SARA-Cov-2 infection in Xiaoshan, Hangzhou, most of them had clinical presentation of respiratory tract infection, but the median course of disease was more than 2 weeks. Further systematic prospective studies about COVID-19 should be urgently needed.

time of study submission, only one patient had not been discharged and no patients died during the study. The median hospital stay was 16.0 days (IQR 12. 5-20.5)  Province, China [1][2][3][4]. The World Health Organization (WHO) declared the outbreak a public health emergency of international concern on January 30th [5].On February 11th, 2020, the novel coronavirus pneumonia was named Corona Virus Disease 2019 (COVID-19) by WHO. COVID-19 had rapidly spread from Wuhan to other areas, by 5th March, 2020, 80565 confirmed cases and 3015 deaths had been reported in China, and 14768 cases were reported in 85 countries and 6 continents [6]. The SARA-Cov-2 was the seventh member of enveloped RNA coronavirus and Full-genome sequencing indicated that SARA-Cov-2 was a distinct clade from the beta coronaviruses associated with human severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) [7]. Previous a study suggested that SARA-Cov-2 spread to humans occurred via transmission from wild animals illegally sold in a local Seafood market, Wuhan [8].The disease causes clinical symptoms in patients including fever, dry cough, productive cough, dyspnea, myalgia, fatigue, normal or decreased leukocyte counts, and radiographic evidence of pneumonia [9], it could even cause patient death in severe cases. In this study, we retrospective reviewed 30 patients with laboratory confirmed SARS-Cov-2 infections in Xiaoshan, and epidemiological and clinical characteristics had been collected. Thus to provide scientific basis for prevention and control of COVID-19 spreads at grassroots units.

Data collection
Hospital information system and Epidemiological investigation reports were used to collect patients' health-related information including demographic, epidemiological, clinical, laboratory data. All data were reviewed by a trained team of public health physicians. Demographic data were recorded including gender, age, weight, height, occupation, permanent residence, family relationship.
Epidemiological data was reported including onset date, family clustering (Great than or equal to one infected family member residing with the patient), exposure and linkage to Hubei Province (close contact with individuals from Hubei Province less than or equal to two weeks before the onset of infection). Clinical data including admission date, discharge date, body temperature, systolic blood pressure (SBP) and diastolic blood pressure (DBP), clinical severity, clinical symptoms, Chest Computed Tomography report (CT report), chronic disease, oxygen therapy, hormone therapy.
Meanwhile, clinical severity was categorized into asymptomatic infection, mild illness, generally illness, and severe illness, critical illness [11]. Clinical symptoms were recorded including fever, shiver, dry cough, expectoration, nasal congestion, runny nose, pharyngalgia, headache and dizziness, fatigue, myalgia, dyspnea, vomiting, diarrhea. Chest CT report was measured with four response categories including without lung CT abnormalities, left lung ground glass opacity, right lung ground glass opacity, and bilateral ground glass opacity. And chronic disease was summarized as hypertension, diabetes, cardiovascular disease, chronic obstructive pulmonary disease (COPD), chronic kidney disease, chronic liver disease. Laboratory data including white blood cell count, lymphocyte count, lymphocyte ratio, neutrophil count, neutrophil ratio, C-reactive protein (CRP), hemoglobin, platelet count. Body Mass Index (BMI) was calculated as weight in kilograms divided by height in meters squared (kg/m 2 ). Hospital stay was calculated in days by subtracting the discharge date and admission date (days), and Course of disease was calculated as the discharge date minus the onset date (days).

Detection method for SARS-Cov-2
Throat swab or nasal swab samples were collected from all of patients after admission, and tested for SARS-Cov-2 with real-time RT-PCR Kit which was recommended by the Chinese Center for Disease Control and Prevention. All samples were tested by Xiaoshan Center for Disease control and

Criteria of discharged from hospital
Base on the COVID-19 treatment protocol (Sixth Edition)[11], Temperature recovered for more than 3 days; Respiratory symptoms improved; Chest CT report shows marked improvement in acute exudative lesions; Have twice negative nucleic acid test of respiratory samples (at least one day apart). Meet the above all conditions that can be discharged. Statistical analysis EpiData 3.1 (Odense, Denmark) was used for data input, and statistical management and analyses were performed using SAS Version 9.4 (SAS Institute, Cary, NC). Summary statistics for continuous variables were expressed as median and interquartile range (IQR), which were compared using the non-parametric Mann-Whitney U test. For categorical variables, we used frequency rates and percentages, the Chi-squared test was used to analyze the differences, and in addition, Fisher exact test was used when the data were limited. Two-sided p value less than 0.05 was considered statistically significant.

Results
This study participants included 30 hospitalized patients with confirmed COVID-19 in Xiaoshan, Hangzhou, and as of February 27, 29 patients had been cured and discharged, and 1 patient was still in hospital without death. The median age was 44.5 years (IQR 33.8-52.3), the median BMI was 24.3 kg/m 2 (IQR 20.7-26.0) and the majority of patients were female (56.7%). Demographic and epidemiological characteristics of study participants by gender were summarized in Table 1. With respect to occupation, Employees accounted for 40.0% of all patients, followed by self-employed (23.3%), retirees (20.0%), agricultural worker (10.0%), and students (6.7%), and none of the them were medical staff. 14 (46.7%) patients were native and showed to be neither visiting in Hubei Province nor having family members who living in Hubei Province, the rest of them had direct or indirect linkage to Hubei Province. In addition, this study had 16 family clustering cases. There were no significant differences between male and female in age, occupation, exposure to Hubei Province, and family clustering cases.

Discussion
In late January, 2020, the number of COVID-19 patients increased rapidly from Wuhan, Hubei Province to all over the world and had become a global health concern [4,7]. 6 human coronaviruses including HCov-OC43, HCoV-229E, HCoV-NL-63, HCoV-HKU1, SARS-CoV, and MERS-CoV were identified [13], SARS-CoV and MERS-CoV could cause severe respiratory syndrome in humans. The sequence of SARS-CoV-2 was relatively different from the six other coronavirus subtypes but can be classified as beta coronavirus [4].The recent studies reported rapid person-to-person transmission of SARS-Cov-2 had occurred [14,15], and another study showed that the spread of SARS-Cov-2 may be stronger than that of SARS-CoV and MERS-CoV [16], according to a previous study [15], the basic reproductive number (R 0 ) was 2.2, which estimated that each patients could spread infection to 2.2 other people on average. The SARS-Cov-2 was spread by close contact and respiratory droplet infection and had an incubation period of 3-7 days, the longest was not more than 14 days [17].
Xiaoshan is one of the districts of Hangzhou, Zhejiang Province, Chinese government announced a travel quarantine of Wuhan, Hubei Province, on January 23, 2020, because of the Spring Festival that Chinese had made several billion trips throughout China to celebrate the Lunar New Year [18]. This social phenomenon was considered a reason of COVID-19 increased spread of infection. Until now, the demographic, epidemiological, clinical and laboratory data of patients were insufficient, especially outside Hubei Province. By February 3rd, 2020, a total of 30 patients were diagnosed and enrolled in this retrospective study, to provide an insight into the control and prevention of COVID-19. The findings showed that 56.7% patients were female and the median age was 44.5 years. Based on previous studies, the age distribution of patients were mostly between 30-60 years [19,20], which was supported by this study. Moreover, other studies suggested that male patients might be the more susceptible to SARS-CoV-2 infection [8,19], and the sample size may be insufficient to find significant differences between genders in this study. According to epidemiological data, only 46.7% patients had exposure to Hubei Province, additionally, 53.3% patients were family clustering, that might demonstrate person-to-person transmission. This result was consistent with those of previous studies [14,15,20], further studies should be needed to identify SARS-Cov-2 transmission and design interventions for these settings.
In terms of clinical characteristics, this study found that the median body temperature was 37.9℃, and more than half (66.7%) of the patients had fever, a portion of them had dry cough and pharyngalgia, resembling that in previous studies [8,20]. Moreover, 1 patient had atypical symptom (myalgia), and this study showed that 3 patients were asymptomatic infection, it may suggest that an even greater number of patients were overlooked because they may present with atypical symptoms of COVID-19. Of the 30 patients, 29 had been cured and discharged and the remaining one would be discharged soon, none of them were dead, one of the reasons was that most of them were mild and generally illness, another reason was that only a small portion of patients had chronic underlying diseases, such as hypertension, diabetes. As previously reported, patients with a history of chronic underlying diseases were at increased risk of becoming critical illness or death [8,14]. However, nearly half of the patients received hormone therapy, and a third received oxygen therapy, no specific treatment had been identified for coronavirus infection except for supportive care at this time [21], all patients were treated in isolation and their close contacts were quarantined, but the present study indicated the median hospital stay and the median course of disease were still more than two weeks, which would result in a serious waste of medical resources, cause considerable economic burden to patients or government. Accordingly, prevention and early diagnosis of this

Availability of data and materials
The datasets used and analyzed during the current study are available from the corresponding author on reasonable request.

Funding
This study did not receive any specific grant from funding agencies in the public, commercial, or notfor-profit sectors.