改进改良加藤厚涂片法诊断血吸虫病的研究

THE STUDY ON IMPROVEMENT OF "Modified Kato-Katz Method" FOR DIAGNOSIS OF SCHISTOSOMIASIS

目的将尼龙绢集卵法与改良加藤厚涂片法（简称加藤法）相结合加以改进，进行实验室预试验和现场研究。方法实验室设计制作EPG（每克粪虫卵数）分别为4、8、16、24、48、96六种阳性粪便标本，现场选定低、中、高三个不同感染率的流行村各粪检居民200人，对各EPG组和每人份粪便按30g、5g、41．7mg粪量分组，分别用改进法和加藤法作粪检，进行阳性检出率和EPG值的比较。结果改进法两组阳性检出率均高于加藤法，EPG在4时，加藤法未能检出，漏检率100％，EPG在24及其以上（新鲜血吸虫卵）两法检出率相等，检出EPG值相近。低度流行村，加藤法未能查出病人，改进法两组均可查出，且30g组优于5g组。中、高度流行村，加藤法检出阳性率渐增，但仍低于改进法；检出阳性病人EPG值，改进法的30g组与加藤法相近。结论EPG在24以下及低度流行区不宜用加藤法查病，采用改进法较好，EPG在24以上和中、高度流行区查病，两种方法均可采用。

Objective To develop a new improved methods in the laboratory and the field by combining modified Kato-Katz method and collecting egg method. Methods Six positive stool sam ples with 4, 8, 16, 24, 48 and 96 EPG respectively were prepared in the laboratory. Three villages with high,middle and lower prevalence were selected as pilot areas and stool samples from 200 per sons in each village were examined. Each stool sample was divided into three parts, e. g. 30g, 5g and 41. 7mg, and examined by irnproved method as well as modified Kato Katz method. Results The detection rate of positive stool in 30g and 5g groups by improved method was higher than that by modified Kato-Katz method. It was negative in the samples with EPG 4 by modified Kato-Katz method, with 100% of missing rate. While there were no significant different in detection rate and EPG count between the improved method and modified Kato-Katz method in detection of samples with EPG 24 and over 24. In the lower prevalence villages, the detection rate by improved method was higher than that by modified Kato-Katz method, and almost same results in the higher and mid dle prevalence villages. Conclusion The improved method is better to use in the stool samples with EPG less 24 and in the lower prevalence villages,than modified Kato-Katz method.