2017-2018年内蒙古乌兰察布市流行性感冒病原学监测结果分析

Analysis of pathogenic surveillance results of influenza in Ulanqab City of Inner Mongolia from 2017 to 2018

目的了解2017年4月~2018年3月乌兰察布市流行性感冒(简称流感)的病原学特点,为流感防控工作提供依据。方法利用实时荧光定量多聚核苷酸链式反应(Real-time PCR)方法,检测流感监测哨点医院送检的流感样病例(influenza-like illness,ILI)咽拭子标本,阳性标本接种狗肾细胞(Madin-daiby canine kidney cells,MDCK)进行分离,采用血凝集抑制试验(Hemag-glutination Inhibition Assay,HIA)鉴定流感病毒的型别。结果共检测ILI咽拭子标本核酸548份,阳性97份,阳性率为17. 70%,其中新甲H1N1型63份(64. 95%)、B型Yamagata 24份(24. 74%)、季节性H3亚型10份(10. 31%);培养鉴定出43株流感病毒,阳性率为7. 85%;核酸检测阳性率高峰值在冬春季(11月~次年3月);流感样病例采集和流感病毒核酸检测阳性数构成比最多的为0~5岁组(42. 27%),阳性率最高的为6~17岁组(26. 05%);不同性别流感病毒核酸检测阳性率差异无统计学意义(χ^2=0. 05,P=0. 819)。按照时间、年龄组、性别分析,病毒分离鉴定的结果与核酸检测的结果基本一致。结论乌兰察布市流感病毒优势毒株为新甲H1N1型,A型H3N2亚型和B型Yamagata系也有出现;防控重点人群为学前儿童、老人,防控重点季节为冬春季。应不断加强病原学监测,根据监测情况及时接种流感疫苗是预防流感的重要措施。

Objective To understand the pathogenic characteristics of influenza( abbreviated as flu) in Ulanqab from April 2017 to March 2018,and to provide evidence for prevention and control of influenza. Methods The throat swab specimens of influenza-like illness( ILI) sent by the sentinel hospital were detected by Real-time PCR methods,and the positive specimens were inoculated with Madin-daiby canine kidney( MDCK) cells. The subtypes of influenza virus were identified by Hemag-glutination Inhibition Assay( HIA). Results A total of 548 samples of ILI throat swabs were detected,and 97 cases were positive,and the positive rate was 17. 70%,including 63 cases of new H1 N1 type( 64. 95%),24 cases of type Yamagata B( 24. 74%),and 10 cases of seasonal H3 subtype( 10. 31%). 43 strains of influenza virus were identified and cultured,and the positive rate was 7. 85%. The high positive rate of nucleic acid detection was in winter and spring( November to March);the highest proportion of influenza-like cases and influenza virus nucleic acid detection were 0 ~ 5 years old group( 42. 27%),and the highest positive rate was 6 ~ 17 years old group( 26. 05%). There was no significant difference in the detection of influenza virus between different genders( χ^2= 0. 05,P = 0. 819). The analysis of time,age group and gender,the results of virus isolation and identification were basically consistent with the results of nucleic acid detection. Conclusion The dominant strain of influenza virus in Ulanqab City was the new H1N1 type,and the A type H3N2 subtype and the B type Yamagata also appeared. The key populations for prevention and control were preschool children and the elderly. The key seasons for prevention and control are winter and spring. The monitoring of pathogens should be continuously strengthened,and timely vaccination against influenza according to surveillance conditions is an important measure to prevent influenza.