Epidemiological and Virological Characteristics of Influenza Viruses Circulating in Cambodia from 2009 to 2011
Epidemiological and Virological Characteristics of Influenza Viruses Circulating in Cambodia from 2009 to 2011
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DOI：
10.1371/journal.pone.0110713
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发表时间：
2014-10-23
期刊：
影响因子：
3.7
通讯作者：
Buchy, Philippe
中科院分区：
文献类型：
--
作者：
Horm, Srey Viseth;Mardy, Sek;Buchy, Philippe
背景资料：柬埔寨国家流感中心（NIC）对2009年至2011年流行的流感病毒株进行监测和特征分析。方法/主要发现：哨点和研究中心从符合流感样疾病、急性下呼吸道感染和基于事件的监测病例定义的患者中收集鼻咽标本进行诊断检测、病毒分离、抗原特征分析、测序和抗病毒药物敏感性分析。在柬埔寨，流感病毒主要在每年6月至11月的雨季发现。抗原性分析表明，A/H1N1 pdm 09分离株属于A/加州/7/2009-like群。2009年，A/H3 N2病毒的流行特征类似于A/布里斯班/10/2007，2010年和2011年则类似于A/珀斯/16/2009。2009年至2011年的柬埔寨B型流感病毒分离株均属于B/维多利亚谱系，以疫苗株B/布里斯班/60/2008和B/Malaysia/2506/2004为代表。从代表性的2009-2011 A/H3 N2和A/H1N1 pdm 09菌株获得的M2基因序列均含有与金刚烷耐药性相关的S31 N突变，除了2011年分离的一种A/H1N1 pdm 09菌株缺乏该突变。在2009年至2011年流行的流感病毒中，未观察到对神经氨酸酶抑制剂的敏感性降低。系统发育分析显示，A/H3 N2菌株每年聚集到一个不同的组，而大多数A/H1N1 pdm 09菌株属于S203 T clade.Conclusions/Significance：在柬埔寨，从2009年到2011年，流感活动发生在全年的雨季，从6月到11月的高峰季节性。季节性流感流行是由于多种遗传上不同的病毒，即使所有分离株的抗原性与参考疫苗株相似。柬埔寨流感病毒株的药物敏感性特征表明，神经氨酸酶抑制剂将是柬埔寨流感治疗和化学预防的首选药物，因为金刚烷类药物预计不再有效。
Background: The Cambodian National Influenza Center (NIC) monitored and characterized circulating influenza strains from 2009 to 2011.Methodology/Principal Findings: Sentinel and study sites collected nasopharyngeal specimens for diagnostic detection, virus isolation, antigenic characterization, sequencing and antiviral susceptibility analysis from patients who fulfilled case definitions for influenza-like illness, acute lower respiratory infections and event-based surveillance. Each year in Cambodia, influenza viruses were detected mainly from June to November, during the rainy season. Antigenic analysis show that A/H1N1pdm09 isolates belonged to the A/California/7/2009-like group. Circulating A/H3N2 strains were A/Brisbane/10/2007-like in 2009 before drifting to A/Perth/16/2009-like in 2010 and 2011. The Cambodian influenza B isolates from 2009 to 2011 all belonged to the B/Victoria lineage represented by the vaccine strains B/Brisbane/60/2008 and B/Malaysia/2506/2004. Sequences of the M2 gene obtained from representative 2009-2011 A/H3N2 and A/H1N1pdm09 strains all contained the S31N mutation associated with adamantanes resistance except for one A/H1N1pdm09 strain isolated in 2011 that lacked this mutation. No reduction in the susceptibility to neuraminidase inhibitors was observed among the influenza viruses circulating from 2009 to 2011. Phylogenetic analysis revealed that A/H3N2 strains clustered each year to a distinct group while most A/H1N1pdm09 isolates belonged to the S203T clade.Conclusions/Significance: In Cambodia, from 2009 to 2011, influenza activity occurred throughout the year with peak seasonality during the rainy season from June to November. Seasonal influenza epidemics were due to multiple genetically distinct viruses, even though all of the isolates were antigenically similar to the reference vaccine strains. The drug susceptibility profile of Cambodian influenza strains revealed that neuraminidase inhibitors would be the drug of choice for influenza treatment and chemoprophylaxis in Cambodia, as adamantanes are no longer expected to be effective.