日本血吸虫卵计量变异的模型建立与参数估计  

Establishment of A Stochastic Model for Variation in Fecal Schistosoma japonicum Egg Count and Estimation of Its Parameters

作　　者：余金明[1,2,3] 袁鸿昌[1,2,3] 陈启明 杨求吉[1,2,3] 

机构地区：[1]上海铁道大学医学院预防医学教研室 [2]上海医科大学 [3]上海师范大学奉贤校区

出　　处：《中华预防医学杂志》1999年第1期37-39,共3页Chinese Journal of Preventive Medicine

摘　　要：目的建立虫卵计量变异的随机模型，并估计描述虫卵计量变异特征的参数。方法随机模型把人群中虫卵计量总变异分成两个来源：①虫卵计量在个体间的变异；②个体内虫卵计量的变异。用具有重复虫卵计数的实际资料对模型的参数进行估计。结果参数Ｍ、ｒ值在各年龄组中不同，ｋ值在各年龄组中近于相同；ｒ和Ｍ值的最佳年龄分割点分别为８和１２岁；模型Ｅ中假定ｋ值在各年龄组中相同，ｒ值在２～７岁和８岁以上年龄组间不同，Ｍ值在２～１１岁和１２岁以上年龄组间不同，ＡＩＣ值最小。结论年龄可能为影响Ｍ，ｒ值的重要因素。Objective To establish a stochastic model suitable for interpreting the variation in fecal Schistosoma japonicum egg count, and to estimate its parameters and to describe it. Methods Total variation in fecal egg count with a stochastic model can be divided into two kinds of sources, ① inter individual variation, and ② intra individual variation. Parameters in the model were estimated with the data collected in actual fecal egg count. Results Parameters M and r differed and k kept nearly the same in various age groups. The best cut off point of r and M for age splitting was at eight and 12 years, respectively. Parameter k was assumed the same in different age groups in the model E, and r differed in the groups of 2～7 years and 8～years of age, and M differed in the groups of 2～11 years and 12～years of age, with a minimum value of Akaike information criterion ( AIC ). Conclusion Age may be an important factor contributing to the estimations of parameters M and r , and the model E was the best one.

关 键 词：日本血吸虫 虫卵计量变异 数学模型 

分 类 号：R532.21[医药卫生—内科学]