2015-2018年成都市某哨点医院儿童流感病原学监测结果分析

Analysis on Pathogenic Surveillance Results of Influenza in Children From A Sentinel Surveillance Hospital in Chengdu City From 2015 to 2018

目的分析成都市2015-2018年儿童流感病原学特征,为制定儿童流感防治策略提供科学依据。方法对成都市某哨点医院2015-2018年采集的流感样病例(ILI)患儿咽拭子标本,采用实时荧光定量RT-PCR法检测标本中流感病毒核酸并分型。描述性统计流感病毒在流感样症状患儿中的检出率和各个亚型或系的构成比,确定不同年份的流行毒株和优势毒株,分析不同亚型流感病毒的流行趋势,比较流感病毒在不同年龄段儿童中分布情况。结果共采集4 144份0~14岁流感样症状患儿标本,其中核酸阳性671份,总阳性率16.19%。其中,检出新A(H1)195份(29.06%),A(H3)197份(29.36%),B(Victoria)138份(20.57%),B(Yamagata)141份(21.01%)。4个年度的流感病毒检出率分别为11.80%、20.72%、23.77%和8.40%。2015-2017年病原流行均呈双峰态,新A(H1)、A(H3)和B型交替流行。<3岁年龄组阳性率最低,为7.30%;6~14岁年龄组阳性率最高,为30.85%。结论除2018年夏季外,监测年度内每月均有流感检出。其中新A(H1)和乙型流行高峰主要为冬春季,夏秋季流行高峰主要为A(H3)。6岁以上学龄儿童是最容易感染流感的人群,应加强防控。

Objective To analyze the pathogenic characteristics of children’s influenza in Chengdu from 2015 to 2018,in order to provide the scientific basic for the strategy of children’s influenza prevention. Methods The throat swab samples of children with influenza-like(ILI) were collected at a sentinel hospital in Chengdu during 2015-2018. The influenza virus nucleic acid was detected and typed by using the method of real-time fluorescence quantitative RT-PCR. The detection rate of influenza virus in children with ILI and the composition ratio of each subtype were described. The epidemic strains and dominant strains in different years were determined. The epidemic trend of virus with different subtypes was analyzed. The distribution of virus in different age groups was compared. Results A total of 4 144 throat swab specimens were collected in ILI children aged 0 to 14 years old,and 671 samples showed positive(16.19%),including 195 strains(29.06%) of A(H1) type,197 strains(29.36%) of A(H3) type,138 strains(20.57%) of B(Victoria) and 141 strains(21.01%) of B(Yamagata). The positive rates of influenza virus from2015 to 2018 were 11.80%,20.72%,23.77% and 8.40%,respectively. The result showed that the peak of influenza epidemic appeared twice in 2015-2017,and the A(H1),A(H3) and B subtype of influenza were alternately prevalent. The positive rate in children under 3 years old was the lowest(7.30%) and the children older than 6 years old had the highest positive rate(30.85%).Conclusion Except for the summer of 2018, the influenza is detected in every month of the monitoring year. The peak of detection rate of influenza A(H1) and B subtype appeares in winter and spring,whereas the peak in summer is caused by A(H3). The school-age children older than 6 years old are the high-risk group of influenza, the targeted protection and control measures should be strengthened.