Rigorous Measures are Vital for Preventing and Controlling Coronavirus Disease 2019 (COVID-19): A Cross-sectional Study

Background worldwide then. Active prevention and control measures have been carried out in China, such as vigorous publicity, active screening and rapid isolation. As the major epidemic area, the passages in and out of Wuhan were temporarily closed since January 23. We aimed to demonstrate the effectiveness of rigorous measures by comparing the characteristics of patients hospitalized before and after implementation of vital measures.

pretty attention to the epidemics of COVID-19 and timely measures around the world.

Background
Since December 2019, a kind of pneumonia with unknown etiology appeared and has spread rapidly in Wuhan, Hubei Province, China. On January 7, 2020, a novel coronavirus was identified by the Chinese Center for Disease Control and Prevention (CDC) [1] and named 2019-nCoV by World Health Organization (WHO) on January 12 (officially named as SARS-CoV-2 finally [2]). Later, WHO declared the diseases caused by 2019-nCoV named Coronavirus Disease 2019  [3]. In early phase, with little awareness of the infectivity and severity of the COVID-19, growing number of people were infected, even including some medical personnel [4]. On January 20, COVID-19 was included in the category B infectious diseases of Law of the People's Republic of China on prevention and control of infectious diseases, and demanded to prevent and control as category A infectious diseases in China [5]. Afterwards, measures like setting up designated hospitals, building interim hospitals, investigating suspicious patients, appealing to everybody fight the epidemic were implemented in China to cut off the transmission of the virus, hold back the spread of the disease, and safeguard the safety and health of people.
At present, the epidemiology, clinical and radiological characteristics have been found out preliminarily [4,[6][7][8]. However, little literature reported the differences among patients diagnosed at different epidemic phases, which may reflect the efficacy of prevention and control work. Here, we collected and compared the clinical and radiological characteristics, treatment and outcomes of patients diagnosed with COVID-19 in two phases which were before or after implementation of vital measures, to reveal the development trend of COVID-19 in Wuhan.

Study design and participants
This study was approved by the ethics committee of Renmin Hospital of Wuhan University (No.2020020).
Patients with COVID-19 admitted to hospital from January 17-23 were defined as Phase I, and those admitted from February 3-9 were defined as Phase II. The diagnostic criteria were based on Guidelines for Diagnosis and treatment of novel coronavirus infected pneumonia, version 6 [9]. All patients were from Renmin Hospital of Wuhan University in Wuhan, China, and were classified into non-severe or severe according to the guidelines above.

Procedures
All patients were laboratory confirmed present SARS-CoV-2 in upper or lower respiratory tract specimens by real-time RT-PCR according to Guidelines for laboratory detection of novel coronavirus infected pneumonia, version 3 [10]. Data of patients with COVID-19 were collected from electronic medical records, including admission time, sex, age, comorbidity, symptoms, laboratory indexes, computed tomography (CT) manifestation, treatment and outcome. The major CT characteristics were described using internationally standard nomenclature of thoracic imaging [11]. CT score was used to quantitatively estimate the degree of pulmonary involvement. Higher score refers to more serious in pulmonary involvement [12]. The time of response on CT image defined as the interval between the first manifestation of viral pneumonia on CT image and the time of improvement. The cut-off date for follow-up was March 13, 2020.

Statistical analysis
Continuous variables were described as means and standard deviations (SD) if they were normally distributed, otherwise, described as median and interquartile range (IQR). Independent group t test or Kruskal-Wallis test was used to compare them. Categorical variables were described as counts and percentages (%), and χ² test or Fisher's exact test were applied to compare them. P value <0.05 (twosided) was considered statistically significant. All statistical analyses were performed using SPSS version 20.0.

Result General situation
The new laboratory confirmed cases in China, in Hubei and in Wuhan from January 17 to March 13 were showed in Figure 1. In the first three days (January [17][18][19] in the figure, new confirmed cases daily in China was consistent with that in Wuhan. After that, new confirmed cases in China were obviously more than Wuhan and Hubei. After action of traffic control was taken in Wuhan, and the passages in and out of it were temporarily closed since January 23, the number of new confirmed cases peaked on February 4. Given that the incubation periods of most patients were within 14 days, we included 97 patients admitted in hospital during January 17-23 (before Wuhan was closed, Phase I), and 79 patients admitted during February 3-9 (fourteen days after the previous period, Phase II).  [11/79]). Common comorbidities in two groups were hypertension, diabetes, chronic obstructive pulmonary disease, cardiovascular diseases and cancer. 7 (7.2%) and 13 (16.5%) asymptomatic patients were in Phase I and II respectively. More patients had fever (70.1% vs. 53.2%, P = 0.028), cough (52.6% vs. 34.2%, P = 0.015)and myalgia (28.9% vs. 11.4%, P = 0.001) in Phase I, while diarrhea was more common in Phase II (11.4% vs. 2.1%, P = 0.013). According to the conditions of patients on admission, 21 (21.6%) cases in Phase I were severe type, while 8 (10.1%) severe cases in Phase II (P = 0.040). Significantly more mild or common type patients admitted in hospital in the latter phase.
As for laboratory findings on admission (Table 2), Except for lymphopenia (41.2% vs. 19.0%) and elevated C-reaction protein (CRP) (30.9% vs. 17.7%), eosinopenia (48.5% vs. 30.4%) and elevated serum amyloid A (SAA) (66.0% vs. 39.2%) were also common in both groups. Compared with Phase I, significantly higher lymphocyte and eosnophils counts and lower levels of CRP and SAA were observed in Phase II. There were 9 (9.3%) and 26 (32.9%) patients were normal in blood routine in Phase I and II respectively (not given in the table). Cardiac and coagulation function of all cases in both groups were normal on admission. 3 patients with elevated liver enzymes and 2 with increased creatinine were discovered on admission in Phase I, while hepatic and renal function of patients in Phase II were all normal (not given in the table Analysis of patients with abnormal CT images showed typical chest CT characteristics in both groups including bilateral and multifocal ground-glass opacity and patchy shadowing with peripheral zone or lower lobe involvement ( Table 3). As the representative of progression of pneumonia [13][14][15]  In this study, we collected data of COVID-19 patients in our hospital before and after the implementation of a variety of rigorous and effective measures. In the group of patients admitted later (Phase II), fewer suffered from comorbidities, indicating that healthy people without comorbidities were also susceptible to SARS-CoV-2. More asymptomatic patients were detected by CT scanning or throat swab in Phase II. The proportion of patients with fever in Phase II was lower, which provides further evidence that fever is not a specific symptom of COVID-19 [7]. Whereas, proportion of diarrhea was higher in Phase II. These findings manifested the existence of recessive infection.
Considering fever as the early screening symptom will miss suspicious infections, and attention should also be paid to some atypical symptoms. Here, we reported reduced eosnophils counts in patients with COVID-19 for the first time, which was reported in patients infected with MERS-CoV [19,20]. Undoubtedly, there are still a lot of problems need to be solved. For example, some convalescent patients with COVID-19 were detected positive in nucleic acid assay when return visit [23,24], that indicated a false negative is presenting in kits and the criterion of discharged may be less strict. Some voice thought that COVID-19 may turn into a chronic disease like chronic viral hepatitis B. The preliminary results of autopsy from organs of died patients with COVID-19 showed that not only lung, but also damaged heart, vessels, liver, kidney, even immune organs [25]. Some researchers thought SARS-CoV-2 was the combination of SARS and HIV. The mechanism underlying pathological changes of this disease needs further study. Along with the passage of SARS-CoV-2, whether the viral virulence will weaken or enhance by variation has not been defined [26,27]. Besides, given COVID-19 has been found in some tropical country, SARS-CoV-2 may exist for a long time. How to fight a "protracted war" of COVID-19 is still under consideration. There are some limitations in our study.
Firstly, the patients were restricted to a hospital, which may be lack of typicality. Secondly, due to the incomplete records, some data like the incubation period and the interval of onset to first treatment was not obtained and analyzed, which can reflect the characteristics of the virus and public awareness to the disease. Authors' contributions: LSY designed the study, collected the data, conducted statistical analysis, interpreted data and drafted the manuscript; YW collected and recorded the data, interpreted results and drafted the manuscript; HHH recorded the data, conducted statistical analysis and drafted the manuscript; YXC conducted statistical analysis, drafted and revised the manuscript; HYF collected, reviewed and analyzed the CT image, and contributed in the writing of the manuscript; YHW collected and reviewed the CT image, made tables and figures and contributed in the writing of the manuscript; JZ collected and recorded the data and contributed in the writing of the manuscript; QBS contributions to the conception and design the study, interpreted data and reviewing the manuscript; HYG contributions to the conception and design the study, collected the data, drafted and revised the manuscript. All authors read and approved the final manuscript.