日本血吸虫病粪检次数与检出机会的估计

作者用实验数据与Poisson分布及负二项分布相拟合,结果与Poisson分布的拟合更为满意。根据Poisson分布的规律推算出检查不同次数感染者能被检出的概率,由此也可根据所要求的检出率确定检查次数。本文所介绍的推算方法与结果可作为粪检工作中确定粪检次数的依据。

ESTIMATIONS ON THE FREQUENCY OF STOOL EXAMINATION AND PROBABILITY OF DETECTION OF OVA OF SCHISTOSOMA JAPONICUM

Pecal examination is a reliable method for detecting schistosomiasis. Though there are several kinds of examination methods, all the conclusions must be based on the existence and the number of eggs in a certain amount of feces, e. g. in 50mg of feoes per sample by Kato's methods. Are conclusions based on such a small sample of feces valid? Is the sensitivity for detection of infected people high enough? These can be answered by calculating the probability distribution of eggs in feces.In this paper, it is shown that experimental data fitted better with the Poisson model than with the negative binomial model.Based on the Poisson distribution the probability of detection of infected cases by different times of stool examination can be calculated. Also the frequency of stool examinations can be determined according to the detection rate required. These calculatory methods and their results may provide a basis to determine the appropriate frequency of stool examination and to estimate the probability of detecting infecting people for preventing schistosomiasis.