All other infectious diseases Colds Influenza 100 200 Cases per 100 people per year Figure 33.18 Colds and influenza. These viral diseases are the lead- ing causes of acute infectious disease in the United States. This pattern is typical for recent years. Colds and influenza cause much higher morbidity as compared to all other infectious diseases 感冒和流感是最常见的传染病,分别 是其他传染性疾病的15倍和2倍。普 Figure 33. 19 Common cold viruses. Transmission electron micrographs fa) Human rhinovirus. Each hinovarus virion is about 30 nm in diameter (b) Human coronavirus. Each coronavirus virion is about 60 nm in diameter 通感冒由鼻病毒或冠状病毒引起感冒和流感是最常见的传染病，分别 是其他传染性疾病的15倍和2倍。普 通感冒由鼻病毒或冠状病毒引起