基于广东省一起风疹爆发疫情评价病例隔离及应急接种措施的效果

Evaluation on Effect of Case Isolation and Emergency Vaccination in a Rubella Outbreak in Guangdong Province

目的评价采取隔离患者和应急接种措施所取得的效果,为控制爆发疫情提供防控建议。方法应用ReedFrost修正型模型模拟不同条件下疾病流行过程,评价指标为对模拟得出的发病数与实际发病数做卡方检验,估计实际防控措施与何种模拟条件相符,进而判断其防控效果。结果模拟从第二代病人开始每代病人被隔离70%的发病曲线与应急接种发挥作用前的实际发病曲线相近,对预测值(86人)和实际值(71人)进行卡方检验,两者没有统计学差异(P>0.05)。模拟不采取任何措施将发生病例594例,从第二代病人开始每代病人被隔离70%将发生病例189例,比不采取任何防控措施减少68.2%的病例发生。实际采取了隔离并于后期开展了应急接种,发生病例98例,比单纯采取隔离措施减少48.1%病例发生。模拟在隔离的基础上于疫情早期(3月16日)开展有效应急接种将发生病例51例,比后期(4月26日)开展应急接种减少48.0%病例发生。结论 Reed-Frost修正型模型对该起爆发疫情的模拟效果比较理想。模型分析显示,采取一定隔离措施和后期应急接种在阻断疫情传播上均能发挥一定作用,早期开展应急接种比后期开展能进一步减少病例的发生。建议当学校等集体单位发生疫苗可预防传染病时,应对所有病人实施隔离的同时尽早开展应急接种,以有效阻断疫情扩散。

Objective Evaluate the effect of case isolation measures and emergency vaccination to provide prevention suggestions for controlling the outbreak of diseases. Methods Reed-Frost correction model was used to simulate the epidemic processes of diseases in different conditions. The evaluation index refers to chi-square test between the simulation incidence and the actual incidence for estimating what kind of simulation conditions to match the actual control measures and for judging the prevention and control effect. Results 70% of the incidence curves were similar to the actual incidence curves before emergency vaccination works. The result of chi square test between the predicted value（ 86） and the actual value（ 71） showed the difference had no statistically significance. 594 cases would occur if no measures were taken in the simulation. 189 cases would occur if 70% of cases in each generation were isolated starting from the second generation,a decrease of 68. 2% compared with not taking any control measures. 98 Cases would occur if taking the isolation measures and carrying out emergency vaccination lately,a decrease of 48. 1% compared with the isolation measures only. 51 Cases would occur if carrying out effective e-mergency vaccination at the base of isolation in the early epidemic（ March 16th）,a decease of48. 0% compared with taking emergency vaccination lately（ April 26）. Conclusion The simulation results for the outbreak by Reed-Frost correction is ideal. The model analysis shows that taking isolation measures and emergency vaccination lately could play a certain role in preventing the spreading of the epidemic. Taking emergency vaccination early could further reduce the occurrence of the cases than lately. We suggest taking the isolation and carrying out emergency vaccination as soon as possible to block the spread of disease quickly when vaccine preventable infectious diseases happen at schools.