甘肃省定西市2014年-2017年流感病原学监测分析

Surveillance and etiological analysis of influenza in Dingxi, Gansu during 2014-2017

目的通过分析定西市近4年流感监测数据,掌握其病原学特征及流行形势,为今后该地区流感防控提供科学依据。方法采用real-time PCR方法对哨点医院采集送检的流感样病例(ILI)咽拭子标本进行核酸检测,对所有阳性标本进行犬肾细胞(MDCK)病毒分离培养、鉴定。结果2763份ILI咽拭子标本中,流感病毒核酸总阳性率为20.59%;阳性样本中乙型、季节性H3和新甲型H1N1的构成比分别为42.36%、35.50%和22.14%。对阳性标本进行病毒MDCK细胞分离培养,获得毒株176株。不同性别间阳性率差异无统计学意义(χ^2=0.239,P>0.05),不同年龄组流感病毒阳性率差异有统计学意义(χ^2=143.75,P<0.05),以5岁~14岁年龄组阳性率最高。每一年度流感流行均呈单峰,主要集中在当年12月-次年3月,各年稍有不同。结论定西市流感呈季节性、单峰型分布,主要集中在冬春季,每年优势病原均有变化,主要感染人群为儿童。因此应继续加强流感病毒的监测及流行季节前儿童流感疫苗的接种。

Objective To analyze the surveillance data of influenza in Dingxi City in the past four years,and grasp the etiological characteristics and epidemic situation of influenza,so as to provide scientific basis for the future prevention and control in the region.Methods Throat swabs were collected from influenza-like illness(ILI)from surveillance sentinel hospitals in Dingxi City,the nucleic acid of virus was detected by real-time fluorescence PCR,and all of the positive samples of influenza virus were isolated and identified with canine kidney cells(MDCK).Results In the 2763 ILI throat swabs,the total positive rate of influenza virus*nucleic acid was 20.59%(596/2763),of which the composition rates of influenza B,influenza A H3 and influenza A H1N1 in positive samples were 42.36%,35.50%and 22.14%.Influenza virus MDCK cell isolation and cultivation were conducted on 596 positive samples,and 176 strains were obtained.There was no statistical significance on the difference between sexes(x^2=0.239,P>0.05).The differences in the positive rate among different age groups had statistical significance(x^2=143.75,P<0.05),with the highest positive rate of 5-14 years old group.High incidence of influenza occurred from December to the next March,with single peak in each year.Conclusion The popular feature of influenza was seasonal and unimodal in Dingxi,Gansu,mainly concentrated in winter and spring.The predominant virus changes every year and the main infected population is in children.Therefore,surveillance of influenza viruses should be strengthened and influenza vaccines should be vaccinated to children before the epidemic seasons.