The need of close monitor of the patients infected with the 2019 novel coronavirus (SARS-Cov-2) in one designated medical institutions in Chengdu: a single-center, retrospective, observational study CURRENT STATUS: POSTED

Objective: To study the clinical characteristics of COVID-19 patients in one designated medical institutions in Chengdu. Methods: 20 patients admitted to one hospital in designated medical institutions in Chengdu with laboratory confirmed SARS-Cov-2 infection. Data were collected from 26 January 2020 to 1 March 2020. Clinical data were collected using Self-constructed questionnaire refer to World health organization nCoV CASE RECORDFORM Version 1.2 28JAN2020. If information was not clear, The team will review the original data from the designated computer. Results: Of the 20 COVID-19 infected patients studied (median age 42.5 years), 4 patients became severe sick and one was critical deteriorated in the process of treatment, they were later transferred to the superior medical institutions for treatment. This patient died after admitted to the intensive care unit (ICU). The other two mild patients remained positive for pharyngeal swabs of SARS-Cov-2 more than 3 weeks, so they were quarantined in a medical facility without medication. All studied cases were infected by human to human transmission without taking protective measures. It requires further confirmation of transmission through contact within families. The most common symptoms at onset of illness were fever in 13 (65%) patients, cough in 9 (45%), headache in 3 (15%), fatigue in 6 (30%), diarrhoea in 3 (15%), and Abdominal pain in 2 (10%). Six patients (30%) developed shortness of breath on admission. The median time from exposure to onset of illness was 6.5 days (interquartile range 3.25-9 days), and from the onset of symptoms to first hospital admission was 3.5(1.25-7) days. Conclusion: Up to the end of February 2020, compared with patients initially infected with SARS-Cov-2 in Wuhan, the symptoms of patients in this study was relatively mild and the patients are easily cured and discharged from hospital. the patients with mild symptoms of COVID-19 is general type of patients infected with SARS-Cov-2 in China. However, The COVID-19 is a self-limiting disease with no effective drug to treat it, it is important to detect and identify severe cases from mild cases early.


Introduction
In the past few decades, there have been epidemics of respiratory infections caused by emerging viruses, they were originated in animals, severe respiratory syndrome coronavirus (SARS-CoV), Middle reducing secondary infections among close contacts and health care workers 8 . The local government restricted the importation of patients externally and the diffusion of patients internally, and determined designated medical institutions for the treatment of diseases in Chengdu, China. World widely, It is also actively advocates to establish the mechanism to prevent and control the epidemic of COVID-19 soon.
The working group describes the clinical characteristics and laboratory findings of patients in Sichuan province infected with SARS-Cov-2 to provide an insight into the prevention and treatment of COVID-19 across China and elsewhere. It will lead to severe infection to die if these patients cannot identify severe patients without management early.

Data sources
The working group conducted a retrospective study focusing on the clinical characteristics of confirmed cases of COVID-19 in designated medical institutions in Chengdu from 26 January 2020 to 1 March 2020. Since the outbreak of COVID-19 in Wuhan, China, strict precautionary measures has been implemented in Sichuan province. Including the creation of fever clinics that exclusively receive patients with suspected SARS-Cov-2 infection, defined as presenting with a fever or any respiratory symptoms, including dry cough, and especially in those with a history of travel to Wuhan or exposure to infected people within two weeks before the onset of illness since January 2020. Travel to the area where the disease is endemic or come into contact with a confirmed patient in the area, it is clustered incidence events in families. Case definitions of confirmed human infection with SARS-Cov-2 are in accordance with the interim guidance from the World Health Organization. An Ingenuity CT scanner (Philips (China) co. LTD) was used and set at 210 mA and 120 kV, with the minimum slice thickness of 1 mm.
Only the patients with a laboratory confirmed infection were enrolled in this study. The working group collected data on 20 patients admitted to hospital with laboratory confirmed of SARS-Cov-2 infection in designated medical institutions in Chengdu, Sichuan province. Information was collected on dates of illness onset, visits to clinical facilities, and hospital admissions. Epidemiological data were collected through brief interviews with each patient. Several doctors interviewed each patient to collect exposure histories during the two weeks before illness onset or after the outbreak of  in Wuhan, including the dates and times of close contact (gathering, living, or working together) with individuals from Wuhan with confirmed or suspected SARS-Cov-2 infection. It also investigated the social network of patient life, including family social network, friend social network, colleague social network and so on.
The working group extracted the medical records of patients by using World health organization nCov CASE RECORD FORM and Self-made scale. A team of doctors who had been treating patients with COVID-19 collected and reviewed the data. The design of the study process was based on Chinese national diagnosis and treatment plan without any intervention measures, concerned about privacy of patients , informed patients of specific rules, and conducted with the informed consent of patients. All information on the content of the study shall be kept by a special person for inspection necessary.
It was urgent need to collect data on this emerging pathogen that the requirement for informed consent was waived. Using a standardized case report form to collect clinical data according to design requirements, the working group would contact the doctor responsible for the treatment of the patient for clarification if the information were not clear.

Laboratory confirmation and treatment
Throat swab specimens were collected from all patients before entering the isolation ward, and were tested by real time polymerase chain reaction (rt-PCR) for SARS-Cov-2 RNA in Local centers for disease control and prevention (CDC). Laboratory confirmation of the virus was performed using real time reverse transcription polymerase chain reaction (rt-PCR). Virus detection was repeated twice with at least 24 hours interval. The patient enters the observation ward to stay monitoring if the patient is undiagnosed or returns home for self-monitoring. The patients will be admitted to an isolation ward for treatment if they are diagnosed with COVID-19 at a designated facility ,the patients can also be transferred to designated medical institutions who were diagnosed CIVOD-19 in other medical institutions. All 20 patients in this study came from isolation wards in designated medical institutions.
Laboratory tests were conducted at admission, including a complete blood count, serum biochemistry, and identification of other respiratory pathogens such as influenza A virus , influenza B virus, and nine infectious markers. Early antiviral treatment could alleviate disease severity and prevent illness progression, found lopinavir/ritonavir combined with arbidol showed antiviral effects in COVID-19.
Most patients received antiviral treatment with interferon alpha inhalation (50 μg twice daily), lopinavir and ritonavir (400 mg twice daily and 100 mg twice daily, respectively), and arbidol (200 mg twice daily) according to treatment plan. Oral Benadol (400mg once daily) were administered if the patient lasted fever for few days. The patient was treated with montmorillonite powder for diarrhea.
Also integrated Chinese medicine in treatment to promote disease rehabilitation through classification methods of traditional Chinese medicine. In a ward, the treatment of general mild disease patients is to use symptomatic treatment, patients suspected of being infected with SARS-Cov-2 were discharged from hospital once the results of two rt-PCR reaction tests taken with 24 hours interval were negative for SARS-Cov-2 antigens.

Statistical analysis
As a previous study has shown that COVID-19 is a self-limited disease and patients generally recovered gradually after treatment, the working group collected clinical indicators for three times.
The first time was 1 day after admission, the second time was 3 days after admission, and the third time was 5 days after admission. Of course, a range of clinical indicators are also the first to be included when the condition of patient suddenly changes. Summarized continuous variables as either means and standard deviations or medians with interquartile ranges. For categorical variables, the team calculated the percentages of patients in each category. All analyses were done with SPSS software, version 17.0.

Patient and public involvement
This was a retrospective case series study and no patients were involved in the study design, also, there were no controls or interventions for patients, setting the research questions by research questionnaire, or the outcome measures directly. No patients were asked to advise on interpretation or writing up of results.
On admission, the blood counts of the 2 (10%) patients showed leucopenia (white blood cell count Abnormalities on chest computed tomograms or radiographs were detected among all of the patients. Seventeen (85%) patients showed more than one lesion sites in chest radiographs (table 1). Typical chest computed tomography findings of infected patients on admission were bilateral or multiple lobular or subsegmental.
Of 20 patients, 4 patients were transferred to superior medical institutions, one of them was sent into the intensive care unit (ICU) for acute respiratory distress syndrome and received mechanical ventilation , but she was dead at last. Two of them were transferred to an isolation point in medical institutions as their rt-PCR results remained positive (table 1).
Fourteen (70%) patients had been discharged and no one died, 2 (10%) patients were quarantined in a medical facility up to now. Discharge standard was based on abatement of fever for at least three days, The pharynx swab nucleic acid test were negative twice every 24 hours, with improved evidence on chest radiography and viral clearance in samples from the lower respiratory tract. On the other hand, the working group also found rt-PCR positive but chest radiographs showed that the lesion had been absorbed. It is not clear how to control these patients, according to current the discharge standards. In this study, the pharyngeal swabs of 2 patients remained positive for a long time and they could not discharged from the hospital. It is an important reason that they stayed longer in hospital. For these 2 patients, swabs remain positive for a long time after the clinical symptoms disappeared. It is not clear if they were infectious to the population, that is also a challenge on discharge criteria of cured patients. More evidence has been gathered to confirm this phenomenon gradually in the future.

Limitations Of Study
This study has several limitations. Firstly, only 20 patients were included. A large number of patients were continually being admitted to hospital as data were being collected, and thus we obtained data on most but not all of the patients with laboratory confirmed infection in Sichuan province during the study period. Secondly, the COVID-19 patients in this study from Sichuan Province only represented a small portion of the total amount of infected cases, the less representativity of clinical features is inevitable. Thirdly, the Patients are transferred to designated medical institutions after being diagnosed by other medical institutions. Therefore, there is a certain bias in the acquisition of clinical data at the initial stage of treatment. Fourthly, the patients were mild illness in designated medical institutions. They will be transferred to the municipal public health center for treatment if the condition of the patient changes suddenly, the working group does not collect clinical data of the patient. All of them could result in biases of clinical observation characteristics. Due to the exploratory nature of the study, which was not driven by formal hypotheses, the sample size calculation was waived.

Conclusion
Compared with the symptoms of the patients with SARS-Cov-2 infection in Wuhan, those patients from Sichuan province in the study were relatively mild. Most of them recovered after treatment and left safely from the hospital. There is no specific drug to treat COVID-19 and no specific vaccine to prevent it. Therefore, we should adopt a multi-strategy prevention and control means to prevention, combined means to carry out clinical treatment to be developed against SARS-Cov-2 infection as soon as possible.
Declarations previous three years; no other relationships or activities that could appear to have influenced the submitted work.
Ethical approval: This study was approved by the Ethics Committee of Chengdu Fifth People ' s hospital (AF/72/2020-01.0).
Data sharing: No additional data available.

Transparency:
The lead authors and manuscript's guarantor affirm that the manuscript is an honest, accurate, and transparent account of the study being reported; that no important aspects of the study have been omitted; and that any discrepancies from the study as planned have been explained.

Consent of Publication:
Written informed consent for publication was obtained from all participants.