To understand the epidemiological characteristics of the eleven important syndrome groups and asthma syndrome in ED-SSS, data of their daily and weekly counts were plotted and shown in Figure 4 and 5, respectively. As can been seen in time series plots in Figure 6 , the seasonal patterns for ED visits due to respiratory syndrome and ILI syndrome were quite similar with high correlation (R = 0.98), while that for asthma syndrome, which had distinct peaks, was nonetheless not highly correlated with ILI syndrome (R = 0.78) nor respiratory syndrome (R = 0.77). Importantly, the ED-SSS was able to detect peaks of these respiratory-related syndromes even occurred in or around the summer season (July to September), though their most noticeable peaks were found during the Chinese new year holidays ( Figure 5B, 5C, 5D ). Like respiratory infection syndrome, visits due to the fever syndrome also showed another peak during the summer (July to September) ( Figure 4A ). ED visits for respiratory syndrome peaked earlier (mid-September) than those visits for ILI (mid-October) and asthma syndrome (end of September, e.g. the transition period between summer and autumn). Visits for pediatric asthma syndrome for children 12 years old and below peaked in mid-autumn, around mid-October (data not shown). Later during winter season (between November and February), there was an increase 