Clinical course and management of 73 hospitalized moderate patients with COVID-19 outside Wuhan

Moderate cases account for the majority in hospitalized patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and can also progress to severe/critical condition. Here, we investigated the clinical course and management of hospitalized moderate SARS-CoV-2 patients. The medical records and follow-up data were analyzed from the SARS-CoV-2 patients outside Wuhan. A total of 73 moderate patients (38 men, 35 women) were included, with median age of 47.0 (38.5–57.5) years. Among them, only one patient (1.4%) died using active treatment to improve symptoms. The median duration of the four main symptoms cough, fever, chest tightness, and fatigue were 11.0, 8.0, 11.0, and 7.0 days, respectively; the median duration of the positive nucleic acid test (NAT) results for SARS-CoV-2 was 16.5 days; the median hospitalization time was 25.0 days in 72 moderate survivors. The duration of cough and fever was positively correlated with the duration of the positive NAT results. On admission, 50% had lymphopenia; less than 30% had abnormal blood biochemistry findings involving hyperglycemia, liver function and myocardial enzymes. At discharge, the laboratory indexes were substantially improved. Two weeks after discharge, 5.6% survivors experienced a recurrence of the positive NAT results. Moderate SARS-CoV-2 patients have a good prognosis by the active treatment. A small proportion of the recovered moderate patients still may be virus carriers and require an additional round of viral detection.

According to the diagnostic and treatment guideline for COVID-19 issued by Chinese National Health Committee (version 3-6) (http://www.nhc.gov.cn/), the clinical classification of COVID-19 severity includes four clinical types: mild, moderate, severe, and critical, of which moderate cases account for the majority in hospitalized patients in China [9,10]. Moderate patients with COVID-19 can also progress to severe/critical condition [11,12]. It is obvious that inhibiting COVID-19 progression can significantly improve the prognosis of the disease. Previous reports have described the general epidemiological findings and clinical characteristics of patients with COVID-19, and differences between subjects with the mild and severe diseases [6,7,13,14]. In the present study, we focused on the clinical course and management of hospitalized moderate patients with COVID-19 in a non-Wuhan area (Xiaochang County) of Hubei Province in order to provide information for understanding the development, progression, and prognosis of the disease.

Ethical approval
The study was approved by the medical ethics committee of the First People's Hospital of Xiaochang County, Hubei Province, China (No. 2020-05).
Besides statistical data including means, medians, P values and patient numbers, we also publicly provided individual clinical data in our figures (e.g. Fig 2). Nevertheless, there are some data from patient participants which refer to sensitive data we could not provide according to the research ethics and applicable local laws. However, we still would like to share the data as many as possible. Therefore, if there are some audiences who are interested in our research and would like to get more data, please contact to corresponding authors freely. We will consult with an ethics committee to ensure data are shared in accordance with participant consent and all applicable local laws.

Patients
We retrospectively analyzed the medical records and follow-up data during hospitalization and after discharge from the patients with COVID-19 consecutively admitted to the Department of infection, the First People's Hospital of Xiaochang County, Xiaogan City, Hubei Province from January to May, 2020. The hospital, which is about 90 km away from Wuhan, China, is the designated hospital for the hospitalization of patients with COVID-19. The following criteria were required to meet for hospital discharge (http://www.nhc.gov.cn/): (1) normal temperature for at least 3 days, (2) significant improvement in respiratory symptoms, (3) obvious signs of absorption of acute exudative lesions on chest computed tomography (CT) images, and (4) 2 consecutive negative nucleic acid test results for SARS-CoV-2 with at least one-day interval. After the recovered COVID-19 patients were discharged, they were transferred to designated quarantine places for a 14-day medical observation, and then underwent another 14-day self-imposed quarantine at home. During follow-up, the patients were asked to conduct the nucleic acid test (NAT) for SARS-CoV-2 14 days after discharge and chest CT scans 28 days after discharge.

Data collection
Epidemiological, demographic, clinical, laboratory, and medical imaging findings and management information from patients' medical records and follow-up data were collected. SARS-CoV-2 pneumonia was diagnosed based on clinical symptoms with typical changes in chest CT image and positive for the nucleic acids of SARS-CoV-2. The clinical classification of COVID-19 severity includes four types (http://www.nhc.gov.cn/): mild, moderate, severe, and critical. Mild cases refer to having only mild symptoms and no manifestation of pneumonia in imaging. Moderate cases refer to having fever, respiratory tract symptoms, and manifestation of pneumonia in imaging. Severe cases meet any of the following signs: a) respiratory distress, respiratory rate�30 beats/ min; b) in the resting state, finger oxygen saturation �93%; c) arterial blood oxygen partial pressure (PaO 2 ) / oxygen concentration (FiO 2 ) � 300mmHg (1mmHg = 0.133kPa). Critical cases meet one of the following criteria: (a) respiratory failure with mechanical ventilation; (b) shock; (c) combination with other organ failure, with ICU monitoring and treatment. The nucleic acid testing for SARS-CoV-2 was performed using quantitative RT-PCR on samples from the respiratory tract (oropharyngeal swab samples) by the Xiaogan Center for Disease Control and Prevention, which is the designated laboratory for SARS-CoV-2 test.

Statistical analysis
Categorical data were expressed as number (%) and evaluated by χ2 or Fisher's exact test; continuous data were expressed as median (interquartile range (IQR)) and evaluated by Mann-Whitney U test; linear correlation was evaluated by Pearson correlation analysis. A two-sided α of less than 0�05 was considered statistically significant. All the statistical analyses were performed with SPSS (version 26.0).

Demographics and clinical characteristics
A total of 79 patients with COVID-19 were included in this study (42 men, 37 women), with median age of 48.0 (39.0-59.0) years. Among them, there were 73 moderate cases (38 men, 35 women) with median age of 47.0 (38.5-57.5) years, 5 severe cases, 1 critical case, and no mild case on admission. The mortality rate (66.7%, 4/6) in severe/critical patients was higher than that (1.4%, 1/73) in moderate patients, whereas there were no significant differences with respect to exposure history, occupation, smokers, comorbidity and so on between moderate patients and severe/critical patients (S1 Table, Fig 1A).
The main symptoms cough, fever, chest tightness, and fatigue during hospitalization lasted for 11.0 (9.  Table 1). The duration of cough (r = 0.426, P = 0.002) and fever (r = 0.543, P = 0.003) was positively correlated with the duration of the positive NAT results, but the duration of chest tightness (r = 0.238, P = 0.275) and fatigue (r = -0.208, P = 0.440) was not correlated with the duration of the positive NAT results in 72 moderate patients (Fig 2).

Laboratory and imaging findings in 72 moderate survivors with COVID-19
On admission, most patients had the normal range of leucocytes (79.2% cases), neutrophils (86.1% cases), and neutrophil percentage (72.2% cases), but a small minority of patients had decreased leucocytes (19.4% cases) and increased neutrophil percentage (26.4% cases). Lymphocytes and lymphocyte percentage were below the normal range in 50.0% of the patients and 40.3% of the patients, respectively. Platelets were within the normal range in 88.9% of the patients, and a small number of patients had decreased platelets (11.1% cases) ( Table 2).
More than half of the patients had a increased level of C-reactive protein (CRP) (65.3% cases), with median CRP level 14.1 mg/L (3.5-29.3). Procalcitonin (PCT) level was within the normal range in 95.8% of the patients ( Table 2).
On admission, all patients showed the normal prothrombin time and the normal activated partial thromboplastin time. The D-dimer level was within the normal range in 87.5% of the patients ( Table 2).
The fasting blood glucose (FBG) level was within the normal range in 79.2% of the patients, with 20.8% increased FBG on admission. Most of the patients had the normal liver function, with 27.8% decreased albumin (ALB) level and 13.9% increased aspartate aminotransferase (AST) level. Almost all patients had the normal range of creatine kinase (CK) and isoenzyme of creatine kinase (CKMB) levels, and most of the patients had the normal range of lactate dehydrogenase (LDH), with 19.4% increased LDH level. All patients had the normal range of blood urea nitrogen (BUN) and creatinine levels ( Table 2).
At discharge, the abnormal laboratory results of the 72 survivors were significantly improved, but there were still some patients who had the abnormal laboratory findings (6.9% decreased leucocytes, 9.7% increased neutrophil percentage, 26.4% decreased lymphocytes, 18.1% decreased lymphocyte percentage, 12.5% increased CRP level, 6.9% increased FBG level, 37.5% decreased ALB level, 8.3% increased AST level, and 4.2% increased LDH level) compared with those on admission ( Table 2).
On admission, 72.2% of the patients had bilateral viral pneumonia, and the remaining 27.8% patients had unilateral viral pneumonia in chest CT images. At discharge, the CT scans were negative in 20.8% of the patients, and the acute exudative lesions were improved  significantly in the remaining 79.2% patients ( Table 1). The representative chest CT images of the moderate survivors were presented in (Fig 3).

Main treatment regimen
All moderate patients received antiviral therapy, including combination of interferon-α and lopinavir/ritonavir tablets or combination of interferon-α and abidol or combination of interferon-α and ribavirin; 34.7% of the moderate patients were given corticosteroid treatment (methylprednisolone or budesonide); 44.4% of the moderate patients were administered with empirical antibiotic treatment (cephalosporins or quinolones  Fig 1A).

PLOS ONE
Clinical course and management of 73 hospitalized moderate patients with COVID-19 outside Wuhan  The 4 patients with re-positive NAT results returned to the hospital for further treatment using the aforementioned regimen. They were 3 women and 1 man, with median age of 60.0 (41.3-72.8) years (S4 Table). All 4 patients had no clinical symptoms. On re-admission, almost all the laboratory results including blood routine, infection biomarkers, coagulation function, and blood biochemistry were within the normal range, and there were no significant changes on chest CT images compared with those at discharge (S5 Table). They underwent the median length of re-hospital stay of 8.5 (6.5-10.5) days, and were re-discharged after having 2 consecutive re-negative NAT results for SARS-CoV-2 with at least one-day interval. Subsequently, the 4 patients re-underwent a 14-day collective medical observation and another 14-day selfimposed quarantine at home. The 4 patients had the re-negative NAT results and the negative chest CT images 14 days and 28 days after re-discharge, respectively (Fig 1, S1 Fig).

Discussion
In this study, we reported 79 patients with SARS-CoV-2 pneumonia, of who the clinical course and management of the 73 moderate cases were described for the first time. These patients came from Xiaochang County, Xiaogan City, a non-Wuhan area of Hubei Province, about 90   km away from Wuhan, who might be the second or third generation cases by human-tohuman transmission of SARS-CoV-2 since the outbreak of COVID-19. In our cohort of the 73 moderate patients, the most common symptoms included cough, fever, chest tightness, fatigue, and gastrointestinal symptoms (S2 Table), the occurrence rates of which were lower compared with the previous reports [9,10,[14][15][16][17][18]. On admission, the main blood routine abnormality was lymphopenia in 50% of the moderate 72 survivors, perhaps suggesting that lymphocytes are the main target of SARS-CoV-2. More than half of the survivors had an increased CRP level, and less than 30% of the survivors had abnormal blood biochemistry findings involving hyperglycemia, liver function, and myocardial enzymes, rather than abnormal renal function and coagulation function in the 72 survivors (Table 2). Many studies have showed that lymphopenia is common in patients with COVID-19 [6,7,13,[15][16][17]; increased CRP levels are often reported in recent studies about COVID-19 [7,15,17]; several studies have reported hyperglycemia in patients with SARS-CoV-2 infection [7,19]; decreased ALB, increased AST, and increased LDH levels are also found in patients with COVID-19 [6,7,13,20]. The occurrence rates of these abnormal laboratory findings were higher compared with our corresponding results.
COVID-19 is a new infectious disease, and there were no effective drugs against SARS--CoV-2 at the time of this study. Therefore, in our cohort of the 73 moderate patients, treatment was focused on symptomatic improvement and preventing or inhibiting the disease progression, including nonspecific antiviral drugs, corticosteroid, empirical antibiotic drugs, oxygen support, and traditional Chinese medicine. Among the aforementioned treatments, corticosteroid may inhibit a cytokine storm and promote the absorption of exudative lesions, whereas antibiotic drugs could prevent or treat secondary bacterial infection [6,7,15].
In the 73 moderate patients, 72 cases recovered and 1 case died using the aforementioned treatments, and the mortality (1.4%) was lower than that of the first generation cases reported by Huang et al in Wuhan, who showed that 4% died in non-ICU patients with SARS-CoV-2 pneumonia [6]. It is possible that these treatments prevent or inhibit COVID-19 progression, or COVID-19 severity or population in the present study is different from that of cases reported by Huang et al. Of course, the small sizes of both studies make comparisons difficult. The median duration of the four main symptoms cough, fever, chest tightness, and fatigue were about 1-2 weeks, and the median duration of the positive NAT results was slightly more than 2 weeks during the hospitalization in 72 moderate survivors ( Table 1). The median hospitalization time was almost 4 weeks, and the median time from onset of disease to discharge was about 1 month in 72 moderate survivors (Table 1). Linear correlation analysis showed there was a positive correlation between the duration of positive NAT results and the duration of cough or fever, rather than chest tightness and fatigue. These results suggest that the onset of the main symptoms such as cough and fever is due to SARS-CoV-2 replication, and these symptoms begin to resolve before the complete viral shedding. Kim et al reported that the median time of defervescence was 9 days (range, 3-18) after symptom onset in 28 patients with COVID-19 [11]. Wang et al showed that fever lasted for about 10 days and the positive NAT results for about 13 days in 88 surviving patients with COVID-19 [21]. These results are in part similar to our report.
At discharge, lymphocytopenia was significantly improved, with still about a quarter cases decreased lymphocytes, and the other abnormal blood routine parameters were also improved significantly, with less than 10% abnormal cases. Infection biomarker the CRP level decreased significantly, with still slightly more than 10% increased CRP level. The abnormal blood biochemistry results including FBG, liver function, and myocardial enzymes were improved significantly, with less than 10% abnormal cases. However, the ALB level was not improved, which seemed to further decrease compared with that on admission ( Table 2). This decrease may be due to the fact that albumin degradation is more than synthesis during the clinical course of the disease. At the time of discharge, chest CT scans showed that the acute exudative lesions were completely absorbed in only about 20% of the patients (Table 1).
During follow-up after discharge, 5.6% of the 72 moderate survivors had the re-positive NAT results, and the remaining survivors had the negative NAT results. Chest CT images were negative in more than 70% of the 68 survivors and were further improved in the remaining survivors 4 weeks after discharge (Table 1). This suggests that the complete absorption of acute exudative lesions on chest CT scan need some time.
The 4 patients with re-positive NAT results were asked to return to the hospital for treatment. They had no symptoms, no abnormal laboratory results, and no exacerbated chest CT findings compared with those at discharge. After undergoing the median length of re-hospital stay of 8.5 days, and they were re-discharged. During subsequent follow-up, the 4 patients had no recurrence. These findings indicate that at least a small proportion of recovered patients still may be virus carriers and require an additional round of viral detection and quarantine. It has been reported that a proportion of COVID-19 patients experience a recurrence of positive NAT results after discharging from the hospital [22][23][24][25]. In our study, the negative NAT results might be false-negative at discharge, which may be associated with the following possibilities. Firstly, we cannot rule out the possibility that inadequate oropharyngeal swab specimens due to poor sampling techniques led to false-negative results [26][27][28]. Secondly, during treatment, the virus may be significantly controlled or removed from the upper respiratory tract, making it difficult to collect from the throat; however, this does not mean that the virus in the lower respiratory tract has also been completely removed. After stopping treatment for some time, the virus appeared again in the upper respiratory tract and was detected positive [22,25]. Finally, the sensitivity of nucleic acid testing or test reliability may be also related to false-negative result; therefore, an additional RT-PCR test should be considered using a kit from a different manufacturer among discharged patients in the future [23,26,27].
Our study has several limitations. First, the total sample size is small. Second, the clinical process and management of severe/critical patients were not analyzed due to only 6 severe/ critical cases on admission. Third, the NAT test for SARS-CoV-2 and laboratory tests were not performed 28 days after discharge so that no more follow-up data can be collected.
In conclusion, the data presented in this study show that the moderate patients with COVID-19 have a good prognosis by the active treatment aimed at symptom improvement. Moreover, a small proportion of the recovered moderate patients still may be virus carriers and require an additional round of viral detection.