2019—2022年四川省阿坝州哨点医院流感监测结果分析

Surveillance results of influenza in the sentinel hospital of Aba Prefecture of Sichuan Province from 2019 to 2022

目的分析四川省阿坝州2019—2022年流感监测结果,了解流感流行规律及毒株亚型特征,为今后流感预警防控提供参考。方法根据《全国流感监测方案(2017版)》收集2019年1月至2022年12月四川阿坝州人民医院的流感样病例(ILIs)鼻咽拭子样本,采用实时荧光PCR方法检测流感病毒及其亚型。结果在2019—2022年阿坝州4202份鼻咽拭子中,PCR检出核酸阳性病例446例,阳性率为10.61%(446/4202),其中甲型占51.57%(230/446),乙型占48.43%(216/446)。不同性别间阳性率明显不同(χ^(2)=135.803,P<0.001),其中女性(19.05%)明显高于男性(6.98%);不同年龄组间阳性率明显不同(χ^(2)=191.346,P<0.001),3~6岁组中最高,为18.16%(180/991)。2019—2022年阿坝州流感流行总体呈下降趋势,冬春季(10月至次年4月)为高发期。另外,不同性别和年龄组流感病毒亚型的构成比明显不同(χ^(2)=91.401,P<0.001;χ^(2)=578.988,P<0.001),甲型H1N1、H3N2和乙型BV亚型交替成为优势型别。结论阿坝州2019—2022年流感流行总体呈下降趋势,冬、春季高发,3~6岁儿童为高发人群,甲型H1N1、H3N2和乙型BV亚型交替流行,提示在流感高发期对重点地区和人群需加强健康教育、提高疫苗接种率并监测毒株亚型转换,进而防止流感疫情暴发与流行。

Objective To analyze the surveillance results of influenza in Aba Prefecture of Sichuan Province from 2019 to 2022,and understand the epidemic and subtyping characteristics of influenza virus,and provide reference for early warning,prevention and control of influenza in the future.Methods According to the National Influenza Surveillance Program-2017 Edition,the nasopharyngeal swabs of influenza like cases(ILIs)were collected from Hospital of Aba Prefecture in Sichuan Province from January 2019 to December 2022.Real time fluorescent PCR was used to detect the subtypes of influenza virus.Results In a total of 4202 nasopharyngeal swabs of ILIs from 2019 to2022,446 positive samples were detected using real-time fluorescent PCR,with the positive rate of10.61%(446/4202).Among them,the type A of influenza virus accounted for 51.57%(230/446),and type B accounted for 48.43%(216/446).The positive rate in females was significantly higher than that in males(19.05%vs 6.98%,χ^(2)=135.803,P<0.001).The positive rate was differed significantly among different age groups(χ^(2)=191.346,P<0.001),and the highest rate was observed in the group of age 3-6 years old at 18.16%(180/991).The positive rate showed a declined trend from 2019 to 2022,and the high-incidence season occurred in winter and spring(from October to April).In addition,the composition rates of different subtypes of influenza virus in different gender or age groups showed significant difference(χ^(2)=91.401,P<0.001;χ^(2)=578.988,P<0.001),and H1N1,H3N2 and BV subtype were the dominant alternate epidemic virus strains.Conclusions Overall,the epidemic trend of influenza showed a significant decline in Aba Prefecture from 2019to 2022,the main infection population is children aged 3-6 years old,and H1N1,H3N2 and BV subtypes were the dominant alternate epidemic virus.Hence,it is necessary to strengthen health education for key areas and populations,enhance the vaccination rate and monitor the transformation of subtypes of influenza virus to effectively prevent the outbreak and epidemic of influenza during the influenza season.