BACKGROUND This retrospective study aimed to investigate the factors associated with disease severity and patient outcomes in 631 patients with COVID-19 who were reported to the Jiangsu Commission of Health between January 1 and March 20 , 2020 . MATERIAL AND
METHODS We conducted an epidemiological investigation enrolling 631 patients with laboratory-confirmed COVID-19 from our clinic from January to March 2020 . Patients' information was collected through a standard questionnaire . Then, we described the patients' epidemiological characteristics, analyzed risk factors associated with disease severity, and assessed causes of zero mortality . Additionally, some key technologies for epidemic prevention and control were identified .
RESULTS Of the 631 patients , 8.46% (n=53) were severe cases, and no deaths were recorded (n=0). The epidemic of COVID-19 has gone through 4 stages: a sporadic phase, an exponential growth phase, a peak plateau phase, and a declining phase . The proportion of severe cases was significantly different among the 4 stages and 13 municipal prefectures (P <0.001). Factors including age> 65 years old, underlying medical conditions, highest fever> 39.0°C, dyspnea, and lymphocytopenia (< 1.0×109/L) were early warning signs of disease severity (P <0.05). In contrast, earlier clinic visits were associated with better patient outcomes (P=0.029). Further, the viral load was a potentially useful marker associated with COVID-19 infection severity .
CONCLUSIONS The study findings from the beginning of the COVID-19 epidemic in Jiangsu Province, China showed that patients who were more than 65 years of age and with comorbidities and presented with a fever of more than 39.0°C developed more severe disease . However, mortality was prevented in this initial patient population by early supportive clinical management.