一起小学乙型流感暴发疫情调查分析

Investigation and treatment of an outbreak of influenza B in a primary school in a district of Tianjin

目的分析天津环城某区一起小学流感暴发疫情的流行病学特征,探讨学校流感发病规律,为制定学校流感暴发疫情防控措施提供依据。方法按照《流感样病例暴发处置指南2012版》,2017年12月4日区CDC开始对该学校流感疫情进行调查,采集10份患者样本,采用RT-PCR方法进行流感病毒检测。结果本次流感暴发共发现病例83例,总罹患率4.33%,男女罹患率分别为4.44%和4.21%,差异无统计学意义(χ^2=0.060,P>0.05)。病例分布于一二三年级的11个班,三年级2班罹患率最高为37.78%,一年级5班罹患率最低为2.17%,各班级的罹患率差异有统计学意义(χ^2=52.570,P<0.05)。一年级罹患率最高为25.56%,二年级罹患率最低为2.56%,各年级差异有统计学意义(χ^2=10.860,P<0.05)。采集10名发病学生的咽拭子标本,4份为乙型(Yamagata)流感病毒核酸阳性,83名病例中仅1人接种流感疫苗。结论学校、幼儿园等集体单位是易发生流感暴发的重要场所,应密切关注疫情动态,积极落实日常消毒卫生管理制度,同时积极开展健康教育,接种流感疫苗,对预防流感暴发有重要意义。

Objective To analyze the epidemiological characteristics of an influenza outbreak in a primary school in a district around Tianjin, and to explore the regularity of influenza outbreak in schools, so as to provide basis for the formulation of prevention and control measures for influenza outbreak in schools. Methods According to the "Guidelines for Handling Influenza-like Case Outbreaks 2012 Edition", on December 4, 2017, CDC began to investigate the influenza epidemic situation in the school. Ten samples of patients were collected and the influenza virus was detected by RT-PCR. Results A total of 83 cases were found in this outbreak, with a total incidence rate of 4.33 %. The prevalence rates of men and women were 4.44 % and 4.21 %, respectively. There was no significant difference( χ^2=0.060,P>0.05).The cases were distributed in 11 classes of grade 12 and 3. The highest incidence was 37.78 % in class 2 of grade 3,and the lowest was 2.17 % in class 5 of a year. There was significant difference in the incidence among classes( χ^2=52.570,P<0.05). The highest incidence was 25.56 % in the first grade, and the lowest was 2.56 % in the second grade.There was significant difference among the grades( χ^2=10.860,P<0.05).Pharyngeal swab specimens of 10 students were collected. Four of them were positive for influenza B virus nucleic acid. Only one of 83 cases was vaccinated against influenza. Conclusion School, kindergarten and other collective units are important places prone to influenza outbreaks. We should pay close attention to the epidemic situation, actively implement the daily disinfection and hygiene management system, actively carry out health education and vaccinate against influenza outbreaks, which is of great significance to prevent influenza outbreaks.