2009—2014年深圳市龙岗区中小学校甲型H1N1聚集性疫情流行动力特征

Epidemic dynamic characteristics of influenza A(H1N1)outbreaks in primary and middle schools of Longgang District in Shenzhen City from 2009-2014

目的通过2009—2014年深圳市龙岗区中小学校甲型H1N1流感聚集性疫情流行传播特征分析,揭示疫情传播规律,为流感新病毒的科学防控提供理论依据。方法对龙岗区2009—2014年中小学校甲型H1N1流感聚集性疫情流行特征进行描述、曲线拟合和相关分析,比较疫情的即时传播速率、扩散方式和基本再生数R0。结果 6年间学校甲型H1N1疫情60起,病例数1 034例,平均罹患率10.50%,病例主要发生在小学人群(67.12%),聚集性疫情基本再生数R0在8~10之间,高于社会一般人群。2009年流行期,疫情高发,流行动力强,累积病例曲线和即时速率呈幂函数方式增长。罹患率与发病人数(r=-0.431,P<0.01)和持续时间(r=-0.386,P<0.01)均呈负相关,发病人数与疫情持续时间呈正相关(r=0.601,P<0.01),传播方式为突破班级限制向全校传播。一般防控措施效果不明显。2013年疫情小活跃期,疫情流行动力微弱,持续时间短,疫情为班内局部传播,报告后立即得到有效控制。结论 2009—2014年深圳市龙岗区中小学校甲型H1N1疫情流行动力高于社会一般人群,2009年甲型H1N1流感聚集性疫情流行动力强于2013年,主要与人群抗体水平有关,应根据疫情的流行动力情况制定策略和采取相应的防控措施。

[Objective] By analyzing the epidemic characteristics of influenza A （H1N1） outbreaks in schools from 2009-2014,to reveal the epidemic spreading law and provide the theoretical basis for the scientific prevention and control of new influenza virus. [Methods] The epidemic characteristics of influenza A （H1N1） outbreaks in primary and middle schools of Longgang District from 2009-2014 were analyzed descriptively ,while the curve fitting and correlation analysis were performed. The propagation ve- locity,the transmission patterns and the basic reproduction number （R0） were compared.[Results] In the past 6 years,there were 60 influenza A （H1N1） outbreaks in schools,involving 1 034 cases,and the attack rate was 10.50%. 67.12% of cases were pri- mary school students. R0 of the outbreaks were between 8 and 10,which was higher than that in general population. The epidemic situation was serious in 2009 ,with the strong motive force, and the cumulative case curves and propagation velocity increased in a power function manner. The attack rate was negatively correlated with case number （r=-0.431 ,P〈0.01 ） and epidemic duration （r=-0.386,P〈0.01）,and there was a positive correlation between case number and epidemic duration （r=0.601 ,P〈0.01）. The communication mode was spread to the whole school through the class, and the general prevention and control measures had no obvious effect. There was a small active phase in 2013,the motive force of epidemic situation was weak and duration was short,the virus spread only in the class,and the epidemic situation had been controlled immediately after the outbreak was reported. [Conclusion] The epidemic intensity of influenza A （H1N1） outbreaks in primary and middle schools of Longgang District in Shenzhen City from 2009-2014 is higher than that in general population. The epidemic intensity of influenza A （H1N1） outbreaks in 2009 is higher than that in 2013 ,which is mainly related to the antibody level. The prevention strategy and control measures should be taken according to the epidemic dynamics status in different period.