2015—2020年铜陵市流行性感冒监测结果分析

目的 了解铜陵市流行性感冒（简称流感）流行特征，为辖区流感防控提供科学依据。方法 通过中国流感监测信息系统收集2015—2020年铜陵市流感样病例（influenza-like illnesses，ILI）、病原学监测和ILI暴发疫情等监测数据，分析ILI的分布特征以及病毒阳性标本的人群、时间分布和分型等流行特征。结果 2015—2020年，铜陵市2家哨点医院报告ILI共计26 862例，其中5岁以下人群占比最高，为46.04%（12 367/26 862）；流感样病例百分比（ILI%）为3.11%（26 862/862 671），各年度ILI%差异有统计学意义（χ2=941.478，P<0.05）；监测年度内共出现8次就诊高峰，主要发生在冬春季。共采集ILI标本8 490份，总阳性率为12.60%（1 082/8 490），男性和女性阳性率分别为14.44%（586/4 059）和11.19%（496/4 431）；各年龄组中，5～14岁组阳性率较高，为22.41%（322/1 437）；各年度中，以2017—2018年度阳性率较高，为20.63%（255/1 236）；不同性别、年龄组、年度间阳性率差异均有统计学意义（χ2=20.038、249.020、941.478，P均<0.05）。不同监测年度中，甲型H1N1、A（H3N2）流感在每个监测年度均有流行，B型流感Victoria 系和 Yamagata 系则呈交替流行。共报告流感暴发疫情20起，均发生在中小学。结论 铜陵市流感流行季节主要为冬春季，5～14岁组儿童青少年为发病重点人群，需加强学生疫苗接种及重点场所流感监测。

Analysis on the surveillance results of influenza virus in Tongling City from 2015 to 2020

Objective  To understand the epidemic characteristics of influenza in Tongling City for evidence in prevention and control of influenza in this area. Methods  Data of influenza-like cases (ILI), together with surveillance data on the etiology and influenza outbreak in Tongling were collected from 2015 to 2020 through Chinese Influenza Surveillance Information System, and analyzed for the distribution of ILI and epidemiological characteristics, including the population with positive virus samples, time distribution and virus classification. Results  A total of 26 862 ILI cases were reported in 2 sentinel hospitals of Tongling from 2015 to 2020. ILI cases were dominated by children under the age of 5 (46.04%, 12 367/26 862).The average ILI% was 3.11% (26 862/862 671), with difference among years (χ2=941.478, P<0.05) . Eight peaks were observed in the monitoring year, primarily seen in winter and spring. In total, 8 490 case samples were collected, of which 1082 were positive (12.60%). The positive rate was 14.44% (586/4 059) and 11.19% (496/4 431) for males and females, respectively, and the highest in population aged between 5 and 14 years (22.41%, 322/1 437). The positive rate was relatively higher between 2017 and 2018 (20.63%, 255/1 236), and was different among genders, ages and years (χ2=20.038, 249.020, 941.478, respectively; all P<0.05). The dominant strains of influenza were differently epidemic in each surveillance year. Influenza A(H1N1) pdm09 virus and influenza A(H3N2) were prevalent, yet influenza B/Victoria and B/Yamagata were alternately prevalent in each surveillance year. A total of 20 influenza outbreaks were reported, all of which were in primary and secondary school students. Conclusion  The influenza usually waves in winter and spring seasons in Tongling City, and primarily affect population between 5 and 14 years of age. The results suggest that it is necessary to strengthen the vaccination of students before the epidemic peak and surveillance in key places.