北京市呼吸道感染疾病中A组肠道病毒流行规律研究

Epidemic Characters of EV-A causing respiratory tract infections in Beijing

目的研究引起呼吸道感染的A组肠道病毒(EV-A)在北京市的分布特征.方法采集北京市呼吸道多病原监测哨点医院的急性呼吸道感染病例标本,提取样本核酸,利用实时荧光PCR方法对肠道病毒核酸进行检测,对核酸检测阳性标本进行VP1区扩增和测序,测序结果在Enterovirus Genotyping Tool(Version 1.0)中进行比对,明确肠道病毒基因型.对EV-A的时间、地区、不同年龄人群和不同疾病类型的分布特征进行统计学分析.结果2014—2018年,在收集到的31932例呼吸道感染病例标本中,共检出肠道病毒810例,完成肠道病毒分型的531例,检出率为1.67%,包括EV-A 280例、EV-B 92例、EV-C 5例、EV-D 45例、HRV 64例、未分型251例.EV-A共检出10个基因型,优势基因型包括CV-A2、CV-A4、CV-A6、CV-A10,流行高峰在6—9月份出现,在2—4岁年龄组检出率最高,北京市中心城区检出率明显高于郊区,EV-A在上呼吸道感染病例中检出率高于肺炎病例和重症肺炎病例.结论2014—2018年,EV-A在北京市的病原谱发生变化,优势基因型CV-A2、CV-A4、CV-A6和CV-A10在不同年份交替出现流行高峰,具有明显季节性、明显年龄差异和地区差异,并且在上呼吸道感染病例中检出率最高.

Objective To investigate the epidemic characters of enterovirus A group(EV-A)causing respiratory tract infections in Beijing.Methods Clinical specimens of acute respiratory tract infection(ARTI)cases were collected from sentinel hospitals in Beijing.Nucleic acids of enteroviruses were purified and were tested by real-time fluorescent PCR.The VP1 gene region were amplified and sequenced for nucleic acids positive samples.The sequences were compared by Enterovirus Genotyping Tool(Version 1.0)to identify the genotypes of the enteroviruses.The statistic analyses of EV-A distribution characters,including time,regions,age groups and disease categories were respectively performed.Results From 2014 to 2018,31932 ARTI cases were collected.A total of 810 cases were enterovirus positive.Genotypes were identified in 531 cases with a detection rate of 1.67%,included 280 cases of EV-A,92 cases of EV-B,5 cases of EV-C,45 cases of EV-D,and 64 cases of HRV,while genotypes of 251 cases were not identified.Ten genotypes of EV-A were identified.The dominant genotypes were coxsakievirus(CV)-A2,CV-A4,CV-A6 and CV-A10.The epidemic peak of EV-A occurred between July and September every year.The detection rate of EV-A among patients age between 2 and 4 years old was the highest.The detection rate of EV-A in central urban area was significantly higher than that in suburban area in Beijing.The detection rate of EV-A in the cases with acute upper respiratory tract infections was higher than that in the cases with non-severe or severe pneumonia.Conclusions From 2014 to 2018 in Beijing,the pathogen spectrum of EV-A changed with CV-A2,CV-A4,CV-A6 and CV-A10 to be predominant in turn every year.The differences in seasonality,age groups and regions were obvious.The detection rate of EV-A among cases of upper respiratory tract infections was the highest.