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日本血吸虫卵计量变异的模型建立与参数估计 |
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余金明 袁鸿昌 陈启明 杨求吉 Sake De Vlas Bruno Gryseels
【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,模型E为最佳模型。 【关键词】 寄生虫虫卵计数 血吸虫,日本 模型,统计学
Establishment of A Stochastic Model for Variation in Fecal Schistosoma japonicum Egg Count and Estimation of Its Parameters YU Jinming*, YUAN Hongchang, CHEN Qiming, et al. *Department of Preventive Medicine, School of Medicine, Shanghai Tiedao University, Shanghai 200070 【Abstract】 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. 【Key words】 Parasite Schistosoma japonicum Models, statistical
过去有关血吸虫病的数学模型研究主要局限于理论研究,较少与实际相结合,现在已经发生了转变[1-3]。改良Kato法诊断血吸虫感染和吡喹酮治疗血吸虫病是近些年来的两个重大突破,它使病原诊断从过去的定性向定量迈出了一大步。但该方法在检测低度感染人群时,会漏诊相当部分的轻度感染者。1992年以来,中国大部分流行区已成为中低度流行区[4]。正确评估改良Kato 法检测的结果,对血吸虫病的防治和科研都有着极为重要的意义。作者通过建立虫卵计量变异的数学模型,使得人[1] [2] 下一页 上一个医学论文: 炼焦工人淋巴细胞微核率与血浆苯并 a 芘浓度相关性研究 下一个医学论文: 表达疟原虫裂殖子表面蛋白1减毒鼠伤寒杆菌的稳定性
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