Comparison of the Clinical Characteristics of Patients With COVID-19 in Suining and Wuhan

Background Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which was rst identied in December 2019 in Wuhan. This study mainly analyzed the clinical characteristics, imaging features, and prognosis of patients with COVID-19 in Suining, one of China's fourth-tier cities, and Wuhan in 2019 and compared data between the 2 cities. Methods A retrospective analysis of the epidemiological history, clinical data, symptom presentation, laboratory test results, chest computed tomography (CT) imaging features, treatment measures and prognosis of 68 patients with COVID-19 diagnosed at Wuhan Red Cross Hospital and 17 patients with COVID-19 diagnosed at Suining Central Hospital from January 23, 2020, to February 27, 2020, was conducted.

pneumonia features on imaging, patients with severe COVID-19 had respiratory distress with a respiratory rate (RR) ≥ 30 times/min, percutaneous oxygen saturation (SpO2) ≤ 93% under a resting state or partial pressure of oxygen(PaO2)/partial pressure of oxygen(FiO2) ≤ 300 mmHg), and patients with critically severe COVID-19 presented shock or respiratory failure, required mechanical ventilation or exhibited other organ failure, requiring intensive care unit (ICU) monitoring.

Methods
The general information, epidemiological characteristics, clinical symptoms and signs, laboratory examination data at admission, imaging features, treatment, length of hospital stay, and prognosis of all patients were collected. Laboratory tests included complete blood count (CBC), biochemical blood tests, liver and kidney function, C-reactive protein (CRP) level, procalcitonin level, D-dimer level, and muscle enzyme levels. This study was approved by the Ethics Committee of Wuhan Red Cross Hospital and Suining Central Hospital and the written informed consent was waived because of the retrospective nature of the study.
Statistical methods SPSS 17.0 was used for the statistical analysis. Normally distributed measurement data are expressed as the mean ± SD; t tests were performed to compare mean values between 2 samples. Nonnormally distributed measurement data are expressed as the median. Categorical data are expressed as a percentage (%); the chi-square test or Fisher's exact test was used to compare differences between 2 groups. P<0.05 indicated that a difference was statistically signi cant.

Demographic and clinical characteristics
This study included 68 patients with COVID-19 in Wuhan and 17 patients with COVID-19 in Suining. The demographic and clinical characteristics are provided in Table 1. The median age of patients in Suining was 40.71 years old (interquartile range (IQR 22.03-59.39), and the median age of patients in Wuhan was 56.04 years old (IQR 41.64-70. 44). The patients in Wuhan were signi cantly older than those in Suining. However, there was no signi cant difference in patient sex between the 2 cities. There were 17 patients in Suining, i.e., 8 males (47.1%) and 9 females (52.9%), and 68 patients in Wuhan, i.e., 35 males (51.5%) and 33 females (48.5%). In terms of epidemiology, the patients in Suining had either traveled or lived in Wuhan before disease onset or had been exposed to patients with con rmed COVID-19 in Suining. The incidence of COVID-19 appeared as family clustering in Suining, as there were 3 families the experienced a clustering of disease onset. In terms of symptoms and signs, fever and cough were the most common symptoms of the 2 groups of patients. There were 9 patients (52.9%) and 8 patients (47.1%) with fever and cough, respectively, in Suining, and 54 patients (79.4%) and 42 patients (61.8%) with fever and cough, respectively, in Wuhan. The incidences of sore throat (4 patients, 23.5%), chills (3 patients, 17.6%) , muscle ache (6 patients, 35.3%) in patients in Suining were higher than those in patients in Wuhan 2 patients (2.9%) with sore throat, 1 patient (1.5%) with chills and 2 patients (2.9%) with muscleache). The patients in Wuhan had othervarious symptoms, including diarrhea (2 patients, 2.9%), headache (2 patients, 2.9%), fatigue (6 patients, 8.8%), hemoptysis (2 patients, 2.9%),inappetence (2 patients, 2.9%), and chest distress(7 patients, 10.3%). Among the patients in Suining, there was 1 patient (5.9%), 2 patients (11.1%) and 5 patients (29.4%) with diarrhea, headache and fatigue, respectively. There was no signi cant difference between the 2 groups. There was only 1 patient with COVID-19 in Suining who experienced dyspnea (5.9%), but there were 23 patients (33.8%) in Wuhan who experienced dyspnea, a statistically signi cant difference (P<0.05). There were 2 asymptomatic patients (11.8%) in Suining but none in Wuhan. There was no signi cant difference in smoking history between the 2 groups of patients. The average incubation period for patients in Suining (10.64 days) was longer than that for patients in Wuhan (7.0 days, P<0.05).

Imaging features
The chest computed tomography (CT) features of patients with COVID-19 were mostly ground-glass opacities, 14 patients (82.4%) in Suining and 40 patients (58.8%) in Wuhan presented these features. Ten patients (58.8%) in Suining presented with patchy shadows in the bilateral lungs, and 31 patients (45.6%) in Wuhan City presented with patchy shadows in the bilateral lungs, there was no signi cant difference between the 2 groups. Pulmonary consolidation was observed in 2 patients (11.8%) in Suining and 26 patients (38.2%) in Wuhan, the difference was statistically signi cant (P<0.05). The proportion of patients with COVID-19 with pulmonary nodules was relatively low, with 1 patient (5.9%) and 2 patients (2.9%) in Suining and Wuhan, respectively; there was no signi cant difference between the 2 groups (Table 1, Figure 1).

Treatments and prognosis
Antiviral therapy and antibiotics were commonly used in COVID-19 treatments. 16 patients in Suining (94.1%) received antiviral therapy or antibiotics, respectively, and 66 patients (97.1%) and 54 patients (79.4%) in Wuhan received antiviral therapy or antibiotics, respectively. There was no signi cant difference between the 2 groups. In terms of other treatment, in Suining, 1 patient (5.9%) received antifungals, 2 patients (11.8%) received steroids, 17 patients (100%) received traditional Chinese medicine, 5 patients (29.4%) received thymosin, and 3 patients (17.6%) received immunoglobulin supportive treatments. In Wuhan, 3 patients (4.4%), 14 patients (20.6%), 9 patients (13.2%), 12 patients (17.6%), and 30 patients (44.1%) received antifungal, steroids, traditional Chinese medicine, thymosin, and immunoglobulin supportive treatments, respectively. More patients in Wuhan than in Suining received immunoglobulin supportive treatments, and more patients in Suining than in Wuhan were treated with Chinese medicine (P<0.05). One patient (5.9%) in Suining received plasma exchange therapy, and 1 patient (1.5%) in Wuhan received hemodialysis. Two patients (11.8%) in Suining received mechanical ventilation, and 27 patients (39.7%) in Wuhan received mechanical ventilation, the difference was statistically signi cant (P<0.05). The average length from symptom onset to hospital visit was approximately 8.44 days(IQR, 1.67 to 15.21) in Wuhan and 4.47days(IQR, 0.04 to 8.9) in Suinning, the time of hospital visit of patients in Wuhan was longer than that in Suining.The average length of hospital stay of patients in Suining was 12.29 days (IQR, 8.92 to 15.66), signi cantly shorter than that of patients in Wuhan (17.49 days, IQR, 6.59 to 28.39) (P<0.05). As of February 27, 2020, 2 patients (11.8%) were still hospitalized in Suining, and 19 patients (27.9%) were still hospitalized in Wuhan. Fifteen patients (88.2%) were discharged in Suining, and 43 patients (63.2%) were discharged in Wuhan. Of the patients in Wuhan,  Recent studies have shown that the prevalence rate of COVID-19 in males and females is close to 1:1 [13]. Our experimental results show that rate of COVID-19 in males and females is also close to 1:1 and there was no signi cant difference in sex between patients in 2 cities. As of February 27, a total of 48,137 cases were diagnosed in Wuhan, with a total of 2,132 deaths, a total of 17 cases were diagnosed in Suining, with no deaths. The incidence rate in Wuhan was 52.99‱, signi cantly higher than that in Suining (0.04‱). Since the identi cation of more than 10 cases of COVID-19 in December 2019 in Wuhan, the disease has rapidly spread throughout the world. SARS-CoV-2 mainly spreads through human respiratory droplets and direct contact. Recently, researchers in Italy found that SARS-CoV-2 RNA can exist on particles in outdoor air and that SARS-CoV-2 can cluster with outdoor particulate matter and enhance the persistence of the virus in the atmosphere by reducing the diffusion coe cient [14]. Studies from Wuhan University also found that SARS-CoV-2 can also spread through aerosols [15]. Wuhan is located on the railway line connecting Beijing and Guangzhou and is the crossroads for the Yangtze River connecting Chongqing and Shanghai. Wuhan is a major transportation hub in China, with high population density [16].In addition, the number of patients with COVID-19 in Wuhan was high, and the large viral load of SARS-CoV-2 in the air in this region, the long persistence and its transmission capacity led to the continuous increase in patient numbers in Wuhan, resulting in a sharp increase in the number of patients and aggravation of the disease in Wuhan. For Suining, a fourth-tier city in China, with low population density, the incidence of COVID-19 was mostly associated with personnel who have been to or were from Wuhan, and the low population density and small viral load of SARS-CoV-2 in the air resulted in a small number of cases. In addition, our study showed that the incubation period of COVID-19 in patients in Wuhan was signi cantly shorter than that in Suining, which was related to the larger viral load of SARS-CoV-2 in the air in Wuhan than that in Suining. Therefore, the incidence rate in Wuhan was higher than that in fourth-tier city. levels in Wuhan were signi cantly higher than those in Suining (29.4%, 5.9%, 17.6%, 5.9%, and 17.6%, respectively) . Chen et al. found that ALT, LDH, D-dimer, CRP and ferritin levels in patients with severe COVID-19 were higher than those in common patients [22]. Chest CT showed that the rate of lung consolidation in patients in Wuhan (38.2%) was much higher than that in patients in Suining (11.8%). In addition, more patients in Wuhan than in Suining received immunoglobulin supportive treatments and mechanical ventilation. The results con rmed that the conditions of patients in Wuhan were more severe than the conditions of patients in Suining, and our results showed that increases in CRP, ALT, blood glucose, CK and D-dimer were important indicators of severe COVID-19. The MuLBSTA scoring system is a new type of early warning scoring system for the risk of death from viral pneumonia; factors included in the score include multilobular in ltration, lymphopenia, bacterial coinfection, smoking history, hypertension and age older than 60 years [23]. The deaths in this study were consistent with the MuLBSTA score. Lymphocyte count and neutrophil abnormalities were observed in patients with COVID-19 both in Wuhan and Suining. The proportion of patients with a lower lymphocyte count in Wuhan were remarkable higher than that in Suining. Additionally, patients with severe COVID-19 had decreased lymphocyte counts, indicating that the virus can attack the human lymphatic system, especially T lymphocytes, weaken immunity, produce a cytokine storm and cause secondary bacterial infection, which can rapidly develop into acute respiratory distress syndrome (ARDS), shock, multiple organ failure, and eventually death.
The average length from symptom onset to hospital visit was approximately 8.44 days in Wuhan and 4.47days in Suinning. The main manifestations of COVID-19 were coughing and fever. Most patients in Wuhan initially thought that they had a common cold and did not seek hospital treatment, sothe time of hospital visit was long. On the other hand, the rst con rmed case occurred in late January 2020 in Suining. During this period, awareness of COVID-19 has been strengthened and people saw a doctor immediately once they had cough or any discomfort, which led to a short time of hospital visit. Moreover, strict investigations were being conducted in various regions to promptly block sources of infection and cut off transmission routes during this time. In addition, medical resources in Wuhan were scarce and Suining had relatively adequate medical resources. Therefore, the disease in fourth-tier city, Suining, was milder than that in Wuhan and incidence rate in Wuhan was higher than that in Suining.

Conclusions
In summary, our research results show that the incidence of COVID-19 in fourth-tier city in China was signi cantly lower than that in Wuhan and that disease severity was also signi cantly lower than that in Wuhan. The occurrence of COVID-19 is mainly clustered, and advanced age, diabetes, hypertension, and cardiovascular diseases can exacerbate the disease. Increases in CRP, ALT, blood glucose, CK, and Ddimer levels can indicate disease severity. Early diagnosis and treatment are important measures to prevent disease aggravation.