新型甲型H1N1流感潜伏期及其影响因素分析

The Analysis of Influenza A(H1N1) Incubation Period and its Influencing Factors

目的估计新型甲型H1N1流感潜伏期并分析其影响因素,为新型甲型H1N1流感的防控提供决策参考。方法利用来源于一次封闭环境下的新型甲型H1N1流感暴发数据,采用失效数据的参数生存分析模型,对新型甲型H1N1流感的潜伏期进行估计,并分析其影响因素。结果新型甲型H1N1流感平均潜伏期为4.65天,95%可信区间为(4.02,5.27)天,72.34%病例在7天内发病,95%的病例在12.96天内发病。与指数分布、对数正态分布、威布尔分布比较,伽玛分布为更适合本研究的参数分布。广泛探索了41个可能的影响因素,单因素分析时未发现对潜伏期有影响的因素,多因素分析发现:出入公共场所佩戴口罩者的平均潜伏期为不戴者的1.21倍,经常打扫卫生者平均潜期为不经常打扫者的70%,经常前往人流密集不通风地方者的平均潜伏期为不经常前往者的45%。结论生存分析的参数模型能较好地描述新型甲型H1N1流感潜伏期的特点,密切接触者的医学观察或隔离以14天为最佳,佩戴口罩、打扫卫生、避免前往人流密集不通风地方等一般防护措施对新型甲型H1N1流感的预防有效。

Objective To estimate incubation period of Pandemic Influenza A（H1N1） and to analyze the influencing factors.Methods Data from a Pandemic Influenza A（H1N1） outbreak in a closed environment was analyze with parametric survival analysis model to estimate Pandemic Influenza A（H1N1） incubation period,describe its characteristics,and explore the influencing factors.Results The incubation period of Pandemic Influenza A（H1N1） is 4.65 days on average,whose 95% confidence interval is（4.02,5.27） days.After infection,72.34% of cases are onset in 7 days and 95% of cases are onset in 12.96 days.Comparing to Exponential,lognormal and weibull distribution,Gamma distribution is the best distribution to describe this outbreak,No factor had found that can affect the incubation period by univariate analysis of 41 factors.By multivariate analysis,we found that the average incubation period of those wearing a mask when accessing to public places is 1.21 times of those not wearing a mask,the average incubation period of those regularly cleaning the dormitory is 70% of those not regularly cleaning the dormitory,and the average incubation period of those often going to crowded places with poor ventilation is 45% of those not often going to this places.Conclusion Parametric survival analysis model can describe the characteristics of Pandemic Influenza A（H1N1） incubation period appropriately.The time of medical observation or isolation of close contacts is 14 days for the best.General non-ventilated protective measures,such as wearing masks,cleaning,avoid visiting crowded and poorly ventilated place,is effective in protecting vulnerable persons.