2014年-2018年重庆市渝中区流感样病例监测结果分析

目的了解本地区流感变化趋势和病原学流行特征,为流感防控提供科学依据。方法前瞻性调查2014年-2018年4个流行年度流感样病例(influenza-like-illness,ILI)占门急诊就诊比例,以及样本流感病毒分离结果。结果筛选出ILI 10403例(0.49%),ILI百分比在夏冬两季达峰值;采集ILI咽拭子3031份,流感病毒核酸检测阳性600份(19.80%),其中季节性H3型297株(49.50%),新甲H1型147株(24.50%),B型Yamagata型94株(15.67%),Victoria型60株(10.00%),混合型2例(占0.33%);冬季(26.92%)和夏季(23.29%)的阳性率显著高于秋季(10.72%)和春季(16.70%),差异有统计学意义(P<0.05);5岁~14岁、15岁~24岁、25岁~59岁和60岁~年龄组人群样本的阳性率分别为14.29%、20.32%、20.52%和17.43%;2014年-2017年3个流行年度以季节性H3型和B型流感病毒为优势毒株,2017年-2018年以新甲H1型、季节性H3型和B型流感病毒为优势毒株。结论本地区流感高发季节为冬季和夏季,各流行年度优势毒株不同,且同一流行年度冬、夏2个流行高峰优势毒株也不同。

Monitoring and analysis of influenza-like illness in Yuzhong District,Chongqing from 2014 to 2018

Objective To investigate the epidemiological and pathologic characteristics of influenza cases in this region,so as to provide reference for prevention and control.Methods We prospectively investigated the composition ratio and pathogenic change of influenza-like illness(ILI)from 2014 to 2017.Results A total of 10403 ILI cases were selected and accounted for 0.48%of all outpatients.The incidence of ILI peaked in the winter and summer of each year.3031 throat swab specimens of ILI were collected and 600 strains of(19.80%)influenza virus were isolated,including 297(49.50%)strains of seasonal A(H3),147(24.50%)strains of A(H1),94(15.67%)strains of type B Yamagata,60(10.00%)strains of Victoria and2 mixed cases of A and B.The positive rate in winter(26.92%)and summer(23.29%)was significantly higher than that in autumn(10.72%)and spring(16.70%),with the differences statistically significant(P<0.05).The positive rates of samples from people at 5-14 years old,15-24 years old,25-59 years old,and 60-years old were 14.29%,20.32%,20.52%,and 17.43%,respectively;from 2014 to 2017,H3 and B influenza viruses were the dominant strains,and new A-H1,seasonal H3 and B influenza viruses were the dominant strains from 2017 to 2018.Conclusion There are two peaks of influenza epidemic in this district,one in winter and the other in summer.The dominant strains of influenza virus are different annually,as well as in winter and summer peaks of each year.