2009-2011年广州地区儿童流感病毒感染的分子流行病学研究

Molecular epidemiological study on influenza virus infections in children in Guangzhou from 2009 to 2011

目的了解2009-2011年广州地区儿童呼吸道感染的流感病毒分子流行病学特点,以达到呼吸道感染监控与预防目的。方法采集2009年1月-2011年12月广州市妇女儿童医疗中心就诊的呼吸道感染患儿咽拭子等标本50 401份,荧光RT-PCR检测流感病毒A、B型,设计扩增流感病毒全基因组序列的引物,随机选取4株病毒进行全基因组序列测定。结果 3年检测流感A型标本共50 401份,阳性标本6838份,总检出率为13.56%;检测流感B标本共43 576份,阳性标本为2038份,总检出率为4.67%;4株流感病毒全基因组序列在PB2基因均出现的位点突变为:D195N、R293K、V344M、I354L、V731I。结论 2009年新甲型流感后2010年流感A型感染率明显降低,但2011年有所回升,而流感B型在2010年比2009年感染率明显上升,但2011年又下降,从2009年开始,新甲型流感成为主要流行株;PB2基因变异相对较大,这些氨基酸点突变均是新出现的突变。

OBJECTIVE To study the molecular epidemiology of influenza virus in children with respiratory tract infections in Guangzhou from 2009 to 2011 so as to achieve the goal of surveillance and prevention of influenza. METHODS A total of 50 401 clinical specimens such as throat swabs were obtained from pediatric patients with respiratory tract infections in Guangzhou Women and Children Medical Centers from Jan 2009 to Dec 2011. The fluorescence RT-PCR was employed to detect the influenza virus A and B, and the primers of influenza virus genome were designed and amplified by RT-PCR, and 4 strains of the virus were randomly selected for the whole genome sequencing. RESULTS Of totally 50 401 specimens of influenza virus A （influenza A） detected, 6838 were cultured positive with the total detection rate of 13.56 %; of totally 43 576 specimens of influenza virus B （Flu B） detected, 2038 were cultured positive with the total detection rate of 4.67%. The locus mutation occurred in the PB2 genes in all 4 strains were D195N, R293K,V344M, I354L, and V731I. CONCLUSION The incidence rate of influenza A virus infection is significantly lower in 2010 than in 2009, however, it rises in 201ti the incidence rate of influenza B virus infection is significantly higher in 2010 than 2009 but descends in 2011. A novel influenza virus has become the predominant epidemic strain since 2009. The mutations of PB2 gene vary significantly, and all the mutations of amino acid emerged for the first time.