A study on the clinical characteristics and management of patients with mild cases of COVID-19 in shelter hospitals from China

Background: To review the clinical characteristics of patients with mild cases of novel coronavirus disease (COVID-19) pneumonia admitted to shelter hospitals and to investigate the management patterns of shelter hospitals. Methods: We collected and analyzed the case data of 931 patients of their general conditions, main clinical presentations, outcomes, laboratory results, imaging. Results: The average age of patients with mild cases of COVID-19 was (cid:0) 46.68 ± 12.13 (cid:0) years. There was no signicant difference in incidence between males and females. The most common clinical presentations were fever (60.79%), cough (47.37%), myalgia and fatigue (17.40%), sore throat (13.86%), sputum (13.86%), diarrhea (9.98%), chest distress and dyspnea (8.38%), nasal congestion (6.02%), and runny nose (5.69%), while 10.10% were asymptomatic. In addition, anxiety and insomnia were present in 12.13% of cases. COVID-19 clinical type: mild, 248 cases (26.64%); moderate, 683 cases (73.36%). Blood biochemical examination showed that some patients exhibited WBC count (26.32%) lower to normal. Most patients tested positive for novel coronavirus nucleic acid (55.45%), while 44.55% tested negative. The rate of positive chest computed tomography (CT )examination ndings was 94.36%. The most common change were ground-glass opacities (48.70%) and multiple patchy opacities (44.58%). Moreover, 65 patients (6.98%) were transferred to designated hospital, primarily due to exacerbation of novel coronavirus pneumonia (32 cases, 49.2%). Conclusions: COVID-19 patients in shelter hospitals were in a relatively mild overall condition and were predominantly of the moderate clinical type. Attention should be paid to asymptomatic positive patients and patients without respiratory symptoms. CT is still the main patient screening method. Shelter hospitals can carry the burden of epidemic prevention and treatment of patients with mild cases of COVID-19.

predominantly of the moderate clinical type. Attention should be paid to asymptomatic positive patients and patients without respiratory symptoms. CT is still the main patient screening method. Shelter hospitals can carry the burden of epidemic prevention and treatment of patients with mild cases of COVID-19.

Background
In December 2019, a novel coronavirus disease (COVID-19) epidemic broke out in Wuhan and has since spread rapidly throughout China and abroad [1,2] through person-to-person transmission [3] , a single infected individual into an otherwise susceptible population was 3.58 [4] ,It has been categorized as a B Class infectious disease, as stipulated in "Law of the People's Republic of China on the Prevention and Treatment of Infectious Diseases", and the appropriate infectious disease prevention and control measures have been implemented. Its high incidence was due it originating in Wuhan, a densely populated area, during a time when many people travel (right before the Lunar Year). Since current medical conditions were unable to ful ll patient requirements, especially in Wuhan, Hubei, where the epidemic was most severe. However, Wuhan has successively renovated and opened 14 shelter hospitals to treat a large number of patients with mild cases of novel coronavirus pneumonia as comprehensively as possible. In this paper, 931 cases of patients with mild COVID-19 admitted to the Zhuankou shelter hospital in a development zone of Wuhan (Hannan District), the xed-point hospital where the Guangxi-Hubei Paired Assistance Epidemic Control Medical Group was located, and their age, sex, onset characteristics, laboratory results, imaging ndings, outcomes, and other indicators were analyzed, with the intention of providing a basis for diagnosis and treatment of mild cases of COVID-19. In addition, the practical work experience at the shelter hospital is reviewed, which provides reference for management of epidemic prevention at shelter hospitals.  1.4 Statistics. SPSS 20 software was used for statistical description and all data analysis. Normally distributed continuous data are shown as ±, non-normally distributed data are shown as median (interquartile range), and categorical variables are shown as frequency (proportion). The chi-square test was used to compare proportions between the two groups. Differences with p < 0.05 were considered statistically signi cant.

Discussion
The COVID-19 pathogen is an enveloped novel coronavirus of the β genus with polymorphic morphology and 60-140 nm diameter. It is highly homologous with the SARS virus and has been named Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) by the International Committee on Taxonomy of Viruses [6] . COVID-19 is a disease characterized primarily by lung in ammation and can also cause injury and corresponding symptoms in the intestines, liver and nervous system. Its primary pathological characteristic is bilateral diffuse alveolar injury [7] .
In the 931 cases retrospectively analyzed in this study, the age range was 14-75 years, the patients were, predominantly, 30-60 years old and the incidence rate was similar between males and females, which is consistent with data released by the Chinese Center for Disease Control and Prevention [8] . Symptoms in patients with mild cases of COVID-19 mainly include fever, cough (dry cough), myalgia and fatigue (the four main symptoms of COVID-19) with a few upper respiratory tract symptoms, such as nasal congestion and runny nose, suggesting that the virus mainly attacks lung tissue. Studies have shown that the target of SARS-CoV-2 is ACE2, which is widely expressed in lung tissue [9] . Chest distress and dyspnea are also rare and are mainly associated with the type of disease, but 19 patients in the present study were transferred to other hospitals due to chest distress and dyspnea. This is an important reason for transfer, so this patient population must be closely monitored in clinical practice. A small number of patients also presented with diarrhea. Notably, the proportion of asymptomatic patients was 10%. Attention should be given to investigating the epidemiological history of patients. Currently, known sources of infection are primarily other people infected with the novel coronavirus (including those in the incubation period or who are asymptomatic) [ 5] , so screening and timely treatment of such patients is an essential link in epidemic prevention and control. The most common chest CT manifestations in COVID-19 patients are bilateral multiple subpleural ground-glass opacities, ne reticular opacities, patchy opacities and vascular thickening [10,11] . The mild disease COVID-19 summarized in this study is consistent with this kind of imaging change, suggesting that chest CT is a screening method worthy of promotion in the population with epidemiological history, so as to reduce the missed diagnosis of asymptomatic or mild symptom patients with COVID-19. Of course, there were patients with mild cases of COVID-19 that suffered from anxiety and insomnia (12.13%). The psychiatrists in our group conducted timely psychological intervention and guidance and our nursing group led a Baduanjin qigong group, and rolling television broadcasts that announced that COVID-19 was preventable and treatable and other interventions have also achieved good results.
In order to properly achieve early diagnosis and treatment of COVID-19 patients and implement collection and treatment of cases in Wuhan, Hubei Province, clinical diagnosis cases were added to the Hubei Province diagnostic criteria in the "Diagnosis and Treatment Protocol for Novel Coronavirus Pneumonia (draft 5th edition)". Namely, suspected cases with the imaging presentation of pneumonia [5] were con rmed as clinically diagnosed cases. In the present study, the proportion of cases testing negative for novel coronavirus nucleic acid was 44.55%, indicating that a very high percentage of clinically diagnosed cases were diagnosed with COVID-19. On February 12, 2020, the total number of clinically diagnosed cases in the Hubei Province increased by 13332 [12] . Most of these cases were predominantly mild and were situated in Wuhan City, which greatly increased the pressure on the Wuhan medical system. In order to address this problem, the Central Steering Committee urgently mobilized 20 national medical assistance groups and medical groups from various provinces and cities, and built shelter hospitals in a short period to treat patients in a timely manner and maximize isolation and treatment of patients with mild cases.
A mobile eld hospital usually uses a medical shelter as a carrier and has different medical or technical support functions. It is designed to respond to sudden disasters, such as natural disasters, shipwrecks, plane crashes, wars, terrorist incidents, public health emergencies and so on [13] . earthquake and the 2010 Yushu earthquake in Qinghai, but this was the rst time they have been used to respond to public health incidents involving infectious diseases, and there have been no other mature experiences from which to draw lessons. Therefore, in order to standardize diagnosis and treatment at shelter hospitals, the Medical Administration and Management Bureau of the National Health Commission established three shelter hospitals that were put into use at early stages and compiled a "Shelter Hospital Operational Manual", which provided an important reference for the management of subsequently established shelter hospitals. The "Shelter Hospital Operational Manual" describes in detail what a shelter hospital is, background information about its construction and general condition of shelter hospitals in Wuhan. It also lays out the criteria for patient admission, check-in and processing, pre-examination and triage, treatment protocols, transfer and processing of severely ill patients, and discharge criteria. In addition, a shelter hospital management system based on the principles of directional admission, centralized isolation, unitized partition management, standardized treatment and bidirectional transfer was established. Shelter hospital operating conditions were strictly implemented and the Zhuankou shelter hospital achieved "zero patient deaths and zero medical personnel infections". The extremely low transfer rate due to exacerbation of primary disease (6.98%) also con rms the feasibility of shelter hospitals for mild cases of COVID-19 during prevention and treatment of a sudden infectious disease. However, among the transferred patients, the number of those with underlying diseases was signi cantly higher than of those without-the difference was statistically signi cant. This indicates that some patients observed in the shelter hospital were still in an exacerbated state and most have underlying diseases. Therefore, during isolation and observation, special attention should be given to patients with underlying diseases.

Conclusions
Taken together, patients with mild cases of COVID-19 have fewer symptoms and milder disease conditions and shelter hospitals can undertake their diagnosis and treatment The professional medical observation and standardized treatment they provide can reduce progression from mild to severe cases and/or critical illness of Hope and Life's shelter. At the same time, standardized management of the source of infection was performed, effectively cutting off the virus transmission route. Thus, the Wuhan shelter hospital played a vital role in the COVID-19 epidemic. Of course, unfamiliarity of medical staff in the operating room of shelter hospitals can lead to low diagnosis and treatment rates. In addition, COVID-19 is highly infectious, [14] therefore creating great psychological pressure on medical personnel, which is also a problem that requires management action.

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