云南省2007-2010年急性迟缓性麻痹病例和健康儿童中非脊灰肠道病毒的比较研究

Comparative study of non-polio enteroviruses isolated from acute flaccid paralysis patients and healthy children during 2007 to 2010 from Yunnan province of China

目的对2007-2010年云南省急性迟缓性麻痹(acute flaccid paralysis,AFP)病例和健康儿童中非脊灰肠道病毒(non-polio enterovirus,NPEV)的分离情况进行比较,分析引起AFP的主要病原并对分离到的病毒基因特征进行分析。方法对云南省2007-2010年AFP病例粪便样本和<15岁健康儿童粪便样本进行病毒分离和基因测序定型,对两类人群中的病毒分离状况进行比较。结果 2007-2010年共从931例AFP病例粪便样本中检测到NPEV 63株,分离率为6.8%(63/931),其中肠道病毒A组(enterovirus A,EV-A)12株,占19.1%(12/63),肠道病毒B组(EV-B)46株,占73.0%(46/63),肠道病毒C组(EV-C)5株,占7.9%(5/63);从1 256份健康人群粪便样本中分离到NPEV 115株,分离率为9.2%(115/1256),其中EV-A 5株,占4.4%(5/115),EV-B 101株,占87.8%(101/115),EV-C 9株,占7.8%(9/115);在两组人群中均未分离到肠道病毒D组(EV-D)病毒。对两组人群中常见病毒的基因进化分析表明,这些病毒具有基因多样性特点。结论云南省2007-2010年连续4年的监测表明,AFP病例中EV-A组病毒和EV-C的分离率(19.1%和7.9%)均高于健康人群(4.3%和7.8%),而健康人群中EV-B组病毒阳性率(87.8%)高于AFP病人(73.0%),EV-A组病毒和EV-C组病毒可能是引起AFP的主要病原。基因进化分析表明,云南省EV-B组病毒中的某些病毒可分为2~5个不同的进化分支(Cluster),具有基因多样性特点。

Objective To compare non-polio enteroviruses(NPEVs)isolation status between acute flaccid paralysis(AFP)patients and healthy children from 2007 to 2010in Yunnan province of China and analyze the predominant pathogens that cause AFP. Methods Virus isolation and identification by sequencing were done for stool samples of AFP cases and healthy children from 2007 to 2010. Results A total of 63 NPEV strains were identified from 1 847 AFP stool specimens with an isolation rate of 6.8%;of which,12strains(12/63,19.1%)were human enterovirus A(EV-A),46strains(46/63,73.0%)were enterovirus B(EV-B),5strains(5/63,7.9%)were enterovirus C(EV-C).A total of 115 NPEV strains were identified from 1,256 healthy children with an isolation rate of 9.2%(115/1 256);of which,5strains(5/115,4.4%)were EV-A,101strains(87.8%)were EV-B,9strains(7.8%)were EV-C.No EV-D viruses were detected from both populations.Phylogenetic analysis on some common viruses showed that these viruses bear multiple genetic characteristics. Conclusions From 2007 to 2010,the isolation rates of EV-A and EV-C viruses in AFP cases were higher than that in healthy children.EV-B virus was the predominant strain in healthy children.Phylogenetic analysis showed EV-B virus in Yunnan province of China can be grouped into 2-5clusters and bear multiple genetic characteristics.