学校乙型流感爆发的传播模式研究

Study on space-time outbreak transmission pattern of influenza B in school

目的探讨乙型流感爆发疫情的时空传播规律,为流感爆发防控提供科学依据。方法采用易感者-染病者-恢复者(Susceptible-Infected-Recovered,SIR)动力学模型特点以及爆发调查资料计算基本再生数;通过详细流行病学调查,绘制疫情时空传播过程图。结果该起乙型流感爆发疫情的基本再生数为1.88;疫情历时8d,共出现病例39例,病例均在同一班级,班级罹患率为78.0%;在无干预情况下,新发病例数呈指数增加趋势,随着时间推移,病例出现的空间顺序有很明显的规律,先从左到右再覆盖至整个班级,新发病例均在上一代病例的附近出现。结论乙型流感在学校爆发时具有较强的传播能力,近距离飞沫传播可能是此次流感爆发的主要传播途径,应及早采取隔离治疗患者、减少近距离接触、加强健康宣教等防控措施。

Objective To explore space -time transmission regularity of influenza B, thus provide evidences for influenza outbreak and prevention and control. Method According to the characteristics of Susceptible - Infected - Recovered （SIR） mechanical model and calculation the basic reproductive number basis outbreak investigations, adoption detail epidemiology investigations and rendering space - time propagation process chart. Results The basic reproductive number of the outbreak was 1.88, epidemic lasted for 8 days, and 39 cases in all, which were in a same class, the attack rate was 78. 0%. Without intervention, the number of new cases showed a exponential growth. Over time, the spatial order of cases had obvious regularity which was from left to fight and then cover all the class averagely. New cases always turned up near the old one. Conclusions Transmission capacity of influenza B outbreaks were powerful in school, droplet transmission was main probable transmission route. Taking isolation measures and cure the patients at early stage, reducing close contact, strengthening health education can control the disease.