Matsuyama Ryota, Akhmetzhanov Andrei R, Endo Akira, Lee Hyojung, Yamaguchi Takayuki, Tsuzuki Shinya, Nishiura Hiroshi
Graduate School of Medicine, Hokkaido University, Sapporo, Japan.
Japan Science and Technology Agency, Core Research for Evolutional Science and Technology, Saitama, Japan.
PeerJ. 2018 Apr 2;6:e4583. doi: 10.7717/peerj.4583. eCollection 2018.
A Rohingya refugee camp in Cox's Bazar, Bangladesh experienced a large-scale diphtheria epidemic in 2017. The background information of previously immune fraction among refugees cannot be explicitly estimated, and thus we conducted an uncertainty analysis of the basic reproduction number, .
A renewal process model was devised to estimate the and ascertainment rate of cases, and loss of susceptible individuals was modeled as one minus the sum of initially immune fraction and the fraction naturally infected during the epidemic. To account for the uncertainty of initially immune fraction, we employed a Latin Hypercube sampling (LHS) method.
ranged from 4.7 to 14.8 with the median estimate at 7.2. was positively correlated with ascertainment rates. Sensitivity analysis indicated that would become smaller with greater variance of the generation time.
Estimated was broadly consistent with published estimate from endemic data, indicating that the vaccination coverage of 86% has to be satisfied to prevent the epidemic by means of mass vaccination. LHS was particularly useful in the setting of a refugee camp in which the background health status is poorly quantified.
2017年，孟加拉国科克斯巴扎尔的一个罗兴亚难民营发生了大规模白喉疫情。难民中既往免疫人群的背景信息无法明确估计，因此我们对基本再生数进行了不确定性分析。
设计了一个更新过程模型来估计基本再生数和病例确诊率，易感个体的减少被建模为1减去初始免疫人群比例与疫情期间自然感染人群比例之和。为了考虑初始免疫人群比例的不确定性，我们采用了拉丁超立方抽样（LHS）方法。
基本再生数范围为4.7至14.8，中位数估计为7.2。基本再生数与确诊率呈正相关。敏感性分析表明，世代时间的方差越大，基本再生数越小。
估计的基本再生数与根据地方病数据发表的估计大致一致，这表明必须达到86%的疫苗接种覆盖率才能通过大规模接种疫苗预防疫情。拉丁超立方抽样在背景健康状况量化较差的难民营环境中特别有用。
