On the estimation of date of infection in an outbreak of diarrhea due to contaminated foods

这项研究考察了估计因食用受某种食源性病原体污染的食物而引起的腹泻暴发感染日期的新方法，如大肠杆菌O-157：H7。本文提出了计算极大似然估计和可信区间的简单方法，假设(1)感染的日期相同，(2)潜伏期服从对数正态分布。此外，为了处理任何概率分布与观察潜伏期不太匹配的情况，使用从过去观察到的潜伏期分布中提取的几个参数来建立数据驱动回归模型，这些参数已累积在专门设计的数据库中。通过许多过去的数据，其中一些来自日本最近爆发的大肠杆菌O抗原157：H抗原7，验证了所提出方法的有效性和适用性。

This research examined new methods for estimating the date of infection in an outbreak of diarrhea caused by eating foods contaminated by some sort of foodborne pathogens such as Escherichia coli O-157 : H7. Simple methods for calculating maximum likelihood estimator and confidence interval are proposed assuming (1) a common date of infection and (2) the incubation period has a lognormal distribution. Further, to deal with the case where any probability distributions do not fit well to the observed incubation periods, data-driven regression models were proposed using several parameters abstracted from the past observed distributions of incubation periods which have been accumulated in a specially designed data base.The validity and applicability of the proposed methods were illustrated with many past data, some of them are from recent outbreaks of Escherichia coli O-antigen 157 : H-antigen 7 in Japan.