Abstract:

Bronchiolitis is an acute lower respiratory tract infection in early childhood. Respiratory syncytial virus（RSV） is the most common etiology of bronchiolitis. Infections with Mycoplasma pneumoniae，Chlamydia pneumonia and Chlamydia trachomatis can also cause bronchiolitis. Bronchiolitis mainly occurs in infants under 2 years of age，with a peak age of 2 to 6 months. Bronchiolitis is the most common reason for hospitalization in infants，and infants under 6 months of age have the highest hospitalization rate. Since bronchiolitis is mainly caused by RSV infection，its seasonal characteristics are similar to those of local RSV infection. Bronchiolitis is a disease with a high incidence but a low mortality rate. Being less than 3 months，prematurity，congenital heart disease and so on are risk factors of severe bronchiolitis.

Key words: bronchiolitis, etiology, epidemiology, risk factor

摘要：

毛细支气管炎是婴幼儿常见的急性下呼吸道感染性疾病。毛细支气管炎主要由病毒感染引起，其中呼吸道合胞病毒（RSV）最常见，肺炎支原体、 肺炎衣原体、沙眼衣原体等感染也可引起毛细支气管炎。毛细支气管炎主要发生于 2 岁以下婴幼儿，发病高峰年龄为 2～6 月龄。毛细支气管炎是导致婴儿住院的最常见原因，6月龄以下的婴儿入院率最高。由于毛细支气管炎主要是 RSV 感染所致，所以其季节特征与当地RSV的流行特征相似。毛细支气管炎是一种发病率高但病死率低的疾病。年龄＜3月龄、早产儿、先天性心脏病等是重症毛细支气管炎的危险因素。

关键词: 毛细支气管炎, 病原学, 流行病学, 危险因素