儿童下呼吸道人类偏肺病毒感染的临床流行特征

Prevalence and clinical features of human metapneumovirus infection in hospitalized children with lower respiratory tract infection

目的了解儿童人类偏肺病毒(hMPV)呼吸道感染的流行情况及临床特征。方法收集2004年8月—2005年1月我院452例急性下呼吸道感染儿童的呼吸道分泌物标本,采用直接免疫荧光抗体法检测呼吸道合胞病毒、流感病毒甲型和乙型、副流感病毒1～3型和腺病毒,以上病毒检测阴性的245份标本再用逆转录-聚合酶链反应法(RT-PCR)检测hMPV M基因,随机挑选部分PCR扩增产物送核苷酸测序作基因分析。结果245份标本中hMPV阳性例数为59例(24．1%),452例患儿中单一hMPV感染率13．1%。冬季月份中hMPV检出数高于其他呼吸道病毒。59例hMPV感染患儿,平均月龄27．7月,各年龄组hMPV检出率差异无显著性(P＞0．05)。hMPV感染者临床特征与其他呼吸道病毒感染无明显差异(P＞0．05)。23份hMPV M基因部分核苷酸片段与GenBank中hMPV M基因序列同源性为82．8%～100%,基因进化树分析提示存在2种不同的hMPV基因。不同hMPV基因型感染者的临床表现差异无显著性(P＞0．05)。结论hMPV是2004年冬季我院儿童下呼吸道感染流行的病毒病原,临床表现无特征性,2种不同基因型感染的临床特征也相似。

Objective To elucidate the prevalence and clinical characteristics of human metapneumovirus （hMPV） in hospitalized children with respiratory infection. Methods A total of 452 hospitalized children with lower respiratory tract infection were observed from Aug 2004 to Jan 2005. Respiratory tract aspirates were collected from all patients within 48 hours after admission. The specimens were routinely tested for respiratory syncytial virus, influenza virus A and B, parainfluenza virus 1 to 3 and adenovirus by direct fluorescent assay （DFA）. The 245 specimens negative by DFA were tested for hMPV by RT-PCR. PCR products of hMPV M gene from some patients were randomly selected for sequencing analysis. Results hMPV was identifled in 59 （24. 1%） of the 245 specimens tested, hMPV infection alone accounted for 13.1% of the infections in the 452 children under study. The prevalence of hMPV was higher than other respiratory viruses in winter. The mean age of hMPV-infected children （n= 59） was 27.7 months. There was no significant difference between age groups in terms of the prevalence of hMPV （P〉0.05）. There were no statistically significant difference in demographics and clinical symptoms between hMPV infection and other common respiratory virus infection. Genotyping for the hMPV M gene from 23 Shanghai patients showed two distinct hMPV genotypes. Sequence analysis of these hMPV M genes showed 82.8%-100% homology to the registered sequence in GenBank. There was no significant difference in clinical characteristics between the 2 genotypes. Conclusions hMPV plays an important pathogenic role in lower respiratory tract infection of children, hMPV prevailed in the winter of 2004. Clinically, hMPV infection can not be discriminated from the infection of other respiratory viruses. Clinical manifestation is similarbetween the two hMPV genotypes,