2009-2017年度甘肃省平凉市流行性感冒病原学特征分析

Analysis on the pathogenic characteristics of influenza in Pingliang city of Gansu province,2009-2017

目的分析平凉市2009年4月至2018年3月监测年度流行性感冒病原学特征,为本市流感防控提供科学依据。方法采集此期间流感样病例标本,用实时荧光定量PCR进行流感病毒核酸检测,用犬肾细胞分离培养,从时间、性别、年龄分布分析流感流行特征。结果共采集标本5158份,流感病毒核酸检测阳性率18.71%(965/5158),其中甲型H1N1亚型、A(H3N2)亚型和乙型流感病毒占比依次为23.79%、35.99%和40.22%。流感病毒年检出率依次为39.32%、10.56%、10.24%、18.38%、15.75%、9.03%、20.98%、12.86%和18.13%;0~6岁组检出率最低,7~17岁组检出率最高,不同年龄组核酸阳性检出率差异有统计学意义(P<0.05);流感病毒核酸阳性病例主要分布在12月至次年3月;分离到流感病毒110株,分离阳性率15.49%。结论平凉市流感冬春季高发,不同年度流感病毒优势株交替频繁,呈混合流行态势,建议加强冬春季流感防控措施,每年九月上旬为重点人群接种流感疫苗。

Objective To reveal the pathogenic characteristics of influenza in the surveillance years during the periods of 2009-2017 in Pingliang city of Gansu province, so as to provide scientific basis for the prevention and control of influenza in the city.Methods The samples from influenza-like illness cases were collected for real-time fluorescent quantitative PCR detection of influenza virus nucleic acids. Cell culture was performed with the canine kidney cell line. The influenza epidemic characteristics were analyzed for time, gender and age distributions.Results For 5 158 surveillance samples, the positive rate of influenza virus nucleic acids was 18.71% (965/5 158), and the proportions of influenza A (H1N1), influenza A (H3N2) and influenza B viruses were 23.79%, 35.99% and 40.22%, respectively. The detection rates of influenza virus in 9 surveillance years were 39.32%, 10.56%, 10.24%, 18.38%, 15.75%, 9.03%, 20.98%, 12.86% and 18.13%, respectively. The incidence rate in 0-6 years old group was the lowest, while the rate in 7-17 years old group was the highest. The differences in the detection rates of nucleic acids by age groups were statistically significant (P<0.05). The influenza virus nucleic acid positive cases were mainly distributed from December to the next March. Ten strains of influenza virus were isolated and the positive rate of isolation was 15.49%.Conclusions The incidences of influenza in Pingliang city were high in winter and spring. The dominant strains of influenza virus were replaced frequently in different years, showing a character of epidemics by mixed dominant strains. The prevention and control measures for influenza in winter and spring should be strengthened. Influenza vaccination should be provided for high risk populations in early September each year.