1起学校甲型H1N1流感暴发流行特征分析

Analysis on epidemiological characterstics of an influenza A (H1N1) outbreak in a school

目的了解靖西市1起学校甲型H1N1流感暴发疫情的流行病学特征,为制定预防控制措施提供依据。方法开展现场流行病学调查,收集分析疫情资料,采取措施控制疫情;采用描述流行病学方法,调查近年来学校师生流感发病及流感疫苗接种情况,流感患者逐一个案调查登记,采集部分患者咽拭子标本送实验室检测确诊。结果累计发病49例,发病率为13.92%(49/352),其中男性28例,女性21例,男∶女性=1.33∶1;学生48例,发病率为14.77%(48/325),教师1例,发病率为3.70%(1/27)。临床特点以发热、咳嗽、咽痛等症状为主,多数患者潜伏期为2～3 d;发热38.0～38.9℃者45例(占91.84%),39.0～40℃者4例(占8.16%);发病时间以11月20日为发病高峰(24例、占48.99%),其次是11月21日(13例、占26.53%);发病班级以1811班发病较多(15例、占30.61%),其次为1810班(12例、占24.49%);发病年龄为12～45岁,13岁最多(27例、占55.10%),其次为12岁(13例、占26.53%)、14岁(8例、占16.33%)。患者咽拭子标本7人份,经实验室检测甲型H1N1流感病毒核酸阳性5人份,阳性率为71.43%。结论靖西市本起学校甲型H1N1流感暴发流行的发生,主要与易感人群积累、学校师生甲型H1N1流感人群免疫水平低有关。

Objective To understand the epidemiological characteristics of an outbreak of influenza A(H1 N1) in a school in Jingxi city,so as to provide the basis for developing preventive and control measures. Methods Field epidemiological investigation was carried out,the epidemic data was collected and analyzed,and measures were taken to control the epidemic.A descriptive epidemiological method was used to investigate the incidence of influenza and influenza vaccination among teachers and students in recent years.Influenza cases were investigated and registered.Throat swabs of some patients were collected and sent to laboratory for diagnosis. Results A total of 49 cases were found,with the incidence of 13.92%(49/352),including 28 males and 21 females,the sex ratio of male to female was 1.33∶1.There were 48 student cases,with the incidence of 14.77%(48/325),and 1 case was teacher,with the incidence of 3.70%(1/27).The main symptoms were fever,cough,pharynx.The latent period of most patients was 2-3 days;there were 45 cases(91.84%) had a fever of 38.0-38.9 ℃,and 4 cases(8.16%) had a fever of 39.0-40 ℃;the cases peaked in November 20(24 cases,48.99%),followed by November 21(13 cases,26.53%).The incidence of class 1811 was the highest(15 cases,30.61%),followed by class 1810(12 cases,24.49%);the age of cases ranged from 12 to 45 years old,and the highest number of cases occurred in age group of 13 years old(27 cases,55.10%),followed by 12 years old(13 cases,26.53%) and 14 years old(8 cases,16.33%).Totally 5 positive samples of influenza A(H1 N1)virus nucleic acid were found among 7 throat swabs,with the positive rate of 71.43%. Conclusion The outbreak of influenza A(H1 N1) in this school in Jingxi city is mainly related to the accumulation of susceptible population and the low immune level of the teachers and students in the school.