Kato-katz′虫卵计量法的定量回收虫卵实验研究

Studies on the Systematic and Sampling Errors of Kato-katz's Quantitative Method by the Recovery of Schistosoma Japonica Eggs Added to Human Feces

通过在阴性人粪中加入血吸虫卵并回收虫卵的方法,对Kato-katz虫卵计量法的虫卵回收率和抽样误差作实验研究,从而对方法的敏感性和适用性作出正确的估价。实验结果表明,在EPG≤100的条件下,该方法的虫卵回收率仅30.0～84.3％,并存在抽样误差,误差大小与粪中的虫卵数及检查片数有关。在EPG<50的地区不宜用Kato-Katz法代替粪孵法作定性检查。

An experimental evaluation of kato-katz's quantitative technique on systematic and sampling errors has been performed by the recovery of S.japonica eggs previously added to the feces of noninfected people with different density of eggs.The results of 24 slides examined (equivatent to lg.feces) with different graduation,2,5,10,20,50 and 100EPG,of eggs added to showed that the mean recovery rates of fecal egg were 30.0% ~84.3%,respectively.Kato-katz's method has had systematic error,being loss of eggs during preparation,but also the number of eggs sampled on the slides.The sampling error could be checked by increasing size of samples of increasing the number of slides examined.According to the economic veiw and the results of the experiment,4~6 slides were satisfactory.