Among these respiratory viruses, 33 9% of the cases were infected by respiratory syncytial virus, 27 3% by influenza virus and 15.0% by parainfluenza virus.

• 在阳性病例中，合胞病毒占33．9%25，流感病毒占27．3%25，副流感病毒占15．0%25，两种以上病毒混合感染占23．8%25。结果提示婴幼儿下呼吸道感染有一半以上是病毒感染所致。