急性毛细支气管炎是一种主要由呼吸道合胞病毒引起的婴幼儿较常见的下呼吸道感染,仅见于2岁以下的婴幼儿,特别是1~6个月的小婴儿,病变主要发生在细小支气管,但肺泡也可受累,因此它属于特殊类型的肺炎。北方多数病例发生在冬春季,南方地区夏秋季也有发病。可有小范围的流 Acute bronchiolitis is a common lower respiratory tract infection in infants and young children primarily caused by respiratory syncytial virus and occurs only in infants under 2 years of age, especially in infants younger than 1 to 6 months. Lesions mainly occur in small bronchi , But alveoli can also be involved, so it belongs to a special type of pneumonia. Most northern cases occurred in winter and spring, the southern region also has the incidence of summer and autumn. There can be a small range of flow