According to the WHO data on Jul. 31th, 2003 [24], a total of 8,096 clinically diagnosed cases of SARS were reported worldwide, with 774 deaths and 26 countries and regions affected (Figure 2a). Most cases were in Asia, Europe, and America. The main countries in Asia were China (including mainland, Macao, Hong Kong, and Taiwan), Singapore, and so on. The total number of cases in mainland China was 5,327, with 349 deaths [53]. The cases were mainly concentrated in Beijing, Guangdong, and Shanxi (Figure 2b) [54]. In total, 2,102 patients were from Hong Kong, Macao, and Taiwan, with 336 deaths [24].