Comparison of clinical features between the two groups of patients with and without COVID-19 is reported in Table 2. There is no significant difference in age and sex between the two groups. Significant differences are found in common symptoms between groups, including fever (p = 0.003), dry cough (p = 0.025), and fatigue (p = 0.007). The respiration rate and heart rate also show significant differences between the two groups (both p < 0.001). Compared with non-COVID-19 pneumonia, the reduction of the WBC count is more pronounced in COVID-19 patients (p < 0.001). The ratio of lymphocyte and ratio of neutrophil also show a significant difference between COVID-19 and non-COVID-19 groups. Although lymphopenia was observed in 32 COVID-19 patients (45.71%), it is not statistically different compared with that in the non-COVID-19 group. C-creative protein (CRP) level and procalcitonin level are also significantly different between the two groups (p < 0.001 and p = 0.007, respectively). Most COVID-19 patients present normal procalcitonin level (82.86%).