人偏肺病毒感染住院儿童的临床特征及病毒基因特性分析

目的 了解急性呼吸道感染住院儿童中人偏肺病毒(hMPV)的感染情况、临床特征及人偏肺病毒基因特性.方法 对2006年2月至5月、2008年3月至4月及2008年9月至2009年2月收集的天津市儿童医院急性呼吸道感染住院儿童的310份鼻咽吸取物标本进行巢式PCR检测hMPV N基因片段,并对其中17株N基因片段进行序列测定,分析序列特征并绘制种系发生树.收集所有阳性患者的临床资料.同时采用多重PCR对N基因阳性标本进行其他常见呼吸道病毒的检测.结果 310份标本中共检出20份(6.5%)hMPV.hMPV阳性患儿的年龄中位数为15.0个月(16天～9岁),其中≤2岁患儿占90.0%(18/20).男性占60.0%(12/20).17株N基因种系发生树分析显示,11株为A2b亚型.20例hMPV阳性患儿的临床诊断均为支气管肺炎,占所有采集的肺炎患儿标本的7.1%(20/282),其临床症状以咳嗽、喘息、呼吸急促、发烧等常见.35%(7/20)需要重症监护,15%(3/20)需要吸氧治疗.平均住院时间为(11.9±4.8)d.A、B型间临床特征未见明显差别.hMPV无明显流行高峰.2例hMPV阳性患儿分别与腺病毒和鼻病毒混合感染.结论 hMPV可引起婴幼儿肺炎等严重疾病.天津地区流行的hMPV以A2b为优势流行型.

Clinical characterization of hospitalized children infected with human metapneumovirus and the virus genetic characters

Objective To investigate the clinical manifestation of hMPV in infants and young chil-dren presented with acute respiratory tract infection and to identify the molecular character. Methods Na-sopharyngeal aspirates were taken from 310 hospitalized pediatric patients from February to May in 2006, March to April in 2008, and September 2008 to February 2009, and the N gene fragments of hMPV were de-tected by nested PCR amplification. Phylogenetic analysis of 17 strains hMPV N genes was performed. The clinical materials of patients were collected and analyzed. All hMPV-positive samples were examined by multi-PCR for other respiratory viruses. Results Of 310 pediatric patients, 20 (6.5%) were positive for hMPV. The median age of hMPV infected children was 15.0 months(from 16 days to 9 years old), 90% (18/20)of the cases were under 2 years, and 60% were male. Phylogenetic analysis of 17 N gene fragments showed that 11 hMPV strains were A2b subtype. 20 hMPV-positive children were subjected to pneumonia, accounting for 7.1% (20/282) among all pneumonia subjects in this study. The common clinical manifesta-tions of hMPV infected patients were cough, wheezing, shortness of breath and fever. 35% (7/20) needed intensive care, 15% (3/20) were given oxygen therapy. The median length of hospital stay was (11.9 ±4.8) d. No significant seasonal distribution of hMPV was displayed. Two patients were coinfected with ade-novirus and rhinovirus respectively. Conclusion hMPV was an important respiratory pathogen in young children subjected to pneumonia in Tianjin. Three subtypes(A2a/A2b, B1, B2) were prevalent in Tianjin, and A2b was the predominant subtype. No significant difference of clinical characters was observed between A and B type hMPV infected patients.