摘要
目的分析郑州市流行性感冒(流感)流行特征,为流感防控提供依据。方法采用流行病学分析方法,描述性分析2021—2022年郑州市流感监测哨点医院报告的流感样病例(influenza like illnell,ILI)特征。对流感病毒核酸检测阳性的ILI咽拭子标本进行病毒分离,选取25株进行流感病毒HA和NA基因序列测定与分析。结果2021—2022年郑州市2658例ILI病例中,流感病毒核酸检测阳性376例,阳性率为14.15%。5~<15岁年龄组阳性率最高,为23.62%,职员组阳性率最高,为20.19%,不同年龄组、不同职业间阳性率比较,差异均有统计学意义(χ^(2)分别为113.241、188.639,P均<0.05);呈现明显的季节性,高峰分布于2021年10月—2022年3月,以及2022年8—10月。流感暴发疫情2021年报告12起,2022年4起,均为学校疫情。阳性标本中,乙型流感Victoria系(Bv系)322份,占85.64%;甲型H3型54份,占14.36%。与当年疫苗株比较,病毒株基因序列HA基因和NA基因核苷酸同源性,14株Bv系分别为97.9%~98.1%、99.2%~99.4%,11株甲型H3分别为97.97%~98.0%、97.3.%~99.4%;氨基酸位点变异方面,14株Bv系HA氨基酸序列均发生抗原表位区域氨基酸变异R148G、N165K、G196E;11株甲型H3 HA基因涉及抗原表位变异为B区K187N,少数毒株NA基因有两处氨基酸D197E(1/11)、E368K(1/11)变异位于NA蛋白头部的抗原决定簇。结论2021—2022年郑州市流感流行呈冬春季高发的季节性特征,并出现了8—10月的夏、秋季小高峰,应加强流感流行高峰期的病原学监测,做好预测预警。Bv系和甲型H3型流感病毒相对疫苗株均有不同程度抗原表位的变异,应继续加强对流感病毒HA和NA基因动态监测,及时筛选和更新流感疫苗。
Objective To understand the epidemic characteristics of influenza in Zhengzhou,and provide the evidence for the prevention and control of influenza.Methods Epidemiological analysis was used to analyze the characteristics of influenza-like illness(ILI)cases reported in influenza surveillance sentinel hospitals of Zhengzhou from 2021 to 2022.Influenza virus were isolated from ILI throat swab specimens with positive nucleic acid test,and 25 strains of influenza virus were selected for HA and NA gene sequence determination and analysis.Results Among the 2658 cases of ILI in Zhengzhou from 2021 to 2022,376 cases tested positive for influenza virus nucleic acid,with a positive rate of 14.15%.The positive rate in the 5~<15 years old age group was highest,which was 23.62%,and the positive rate in the staff group was the highest,which was 20.19%.The differences of positive rate were statistically significant among different age groups and occupations(χ^(2)=113.241,188.639,respectively;all P<0.05).Obvious seasonality was shown,and the peaks were distributed from October 2021 to March 2022,and from August to October 2022.There were 12 influenza outbreaks reported in 2021,and 4 in 2022,all of which occurred in school.Among the positive specimens,322 belonged to influenza B Victoria lineage(Bv lineage),accounting for 85.64%;and 54 belong to influenza A H3 type,accounting for 14.36%.Compared to the gene sequences of vaccine strains in the same year,the nucleotide homology of HA and NA genes of virus strains was 97.9%-98.1%and 99.2%-99.4%in 14 Bv strains,and 97.97%-98.0%and 97.3%-99.4%in 11 H3 HA strains,respectively.In term of amino acid site variations,the HA amino acid sequences among all 14 strains of Bv line all had antigenic epitope region amino acid variations R148G,N165K,and G196E;The HA gene of 11 A H3 strains involves antigenic epitope variation in the B region K187N,while a few strains of NA genes had two amino acid D197E(1/11)and E368K(1/11)mutations located in the antigenic determinant cluster of the NA protein head.Conclusions The influenza epidemic in Zhengzhou from 2021 to 2022 showed the seasonal characteristics of high incidence in winter and spring,with a small peak in summer and autumn from August to October.The etiological surveillance should be strengthened during the peak period of influenza epidemic to make predictions and early warnings.Influenza Bv and A H3 viruses have different degrees of epitope variation relative to vaccine strains.Dynamic monitoring of influenza virus HA and NA genes should be strengthened continuously,and influenza vaccines to should be screened and updated timely.
作者
胡乃月
王治国
戴蕾
王琳
赵升
僧明华
程春荣
HU Naiyue;WANG Zhiguo;DAI Lei;WANG Lin;ZHAO Sheng;SENG Minghua;CHENG Chunrong(Department of Microbiology,Zhengzhou Center for Disease Control and Prevention,Zhengzhou,Henan 450007,China;Henan Center for Disease Control and Prevention)
出处
《现代疾病预防控制》
2024年第3期196-202,共7页
MODERN DISEASE CONTROL AND PREVENTION
关键词
流感病毒
监测分析
分子变异
Influenza virus
Surveillance analysis
Molecular variation
