杭州地区儿童流感样病例人偏肺病毒流行情况分析

Human metapneumovirus infection in children with influenza-like illness in Hangzhou

目的 了解杭州市儿童流感样病例人偏肺病毒（hMPV）的感染情况,并描述其流行病学特征.方法 选取2011年1月至2012年12月浙江大学医学院附属儿童医院门诊流感样病例的咽拭子样本共1164份.对样本进行hMPV核酸检测,阳性样本用RT-PCR法扩增hMPV融合蛋白（F）基因片段,取扩增阳性产物进行基因测序和序列分析.不同年龄组hMPV检出率比较采用x2检验.结果 在1164份儿童流感样病例的咽拭子样本中检出hMPV阳性73份,阳性率为6.27％;检出率最高的年龄组为＞2 ～4岁组,为15.00％（33/220）,不同年龄组检出率差异有统计学意义（x2 =40.69,P＜0.05）.hMPV在多数月份均有检出,但以冬春季检出率为高,检出率最高的月份为2012年12月,为25.53％（12/51）.选取24份阳性样本进行基因序列分析,其中14份为B1亚型,2份为B2亚型,8份为A2亚型.2011年以B1型为主（10/12）,2012年以A2型为主（8/12）.24株hMPV之间的核苷酸同源性为81.6％ ～ 100.0％.结论 杭州市儿童流感样病例中有一定比例的hMPV感染,以冬春季为高峰,＞2 ～4岁组检出率最高,不同基因型的病毒株可能存在交替流行.

Objective To investigate the epidemiological characters of human metapneumovirus （hMPV） infection in children with influenza-like illness （ILI）.Methods A total of 1 164 throat swabs were collected from children with ILI symptoms in Children＇s Hospital,Zhejiang University School of Medicine from January 2011 to December 2012.hMPV was detected by using nucleic acid assay,the fusion （F） protein gene of hMPV was amplified by RT-PCR,gene sequencing was performed and the sequences were compared with those in GenBank.Positive rates of hMPV in different age groups were compared with Chi-square test.Results Among 1 164 samples,hMPV was positive in 73 （6.27%） samples.hMPV infection was the most popular in 〉2-4 y age group （33/220,15.0%）,and the positive rates of hMPV in different age groups were of statistical significance （x2 =40.69,P 〈 0.05）.hMPV infection occurred throughout the year,but it was most common in winter and spring.The highest incidence of hMPV infection was observed in December 2012 （12/51,25.53%）.Among 24 samples of hMPV,14 were with genotype B1,2 were with genotype B2,and 8 were with genotype A2.The most common genotype was B1 in 2011 （10/12）,and A2 in 2012 （8/12）.Homology between nucleotide sequences of the 24 samples of hMPV were 81.6% to 100.0%.Conclusions hMPV infection exists in children with ILI in Hangzhou,and the epidemic seasons are winter and spring.hMPV infection is more likely to be found in children aged 2 to 4 years old,and different genotypes may predominated alternately.