采用间接血凝试验(IHA)确定湖区血吸虫病中度流行区化疗对象的可靠性分析

目的分析ＩＨＡ法在湖区血吸虫病中度流行区确定化疗对象的可靠性。方法选择洞庭湖沿岸疫情基本一致的流行村６个，居民感染率均在１０％～１５％之间。每年对其一半人群采用ＩＨＡ法过筛，抗体滴度在１： １０及以上者作为化疗对象，同时用Ｋａｔｏ－Ｋａｔｚ粪检法考核化疗效果。结果ＩＨＡ法阳性者包括了９０．７％～９６．１％的Ｋａｔｏ－Ｋａｔｚ粪检阳性者在内。１９９７、１９９８年ＩＨＡ和粪检都为阳性的人群，１９９９年粪检阴转率为８０．５％和７７．７％。ＩＨＡ和粪检均为阴性的人群，粪检考核阴性率仍保持９６．４％到 ９８． ３％。单就１９９７年粪检阳性者而言，１９０９年粪检阴转率为 ７４． ４％。结论在湖区血吸虫病中度流行区，采用ＩＨＡ确定化疗对象，可将９０％以上的粪检阳性对象和粪检查不出的大量血吸虫病人包括在内，其阳性和阴性结果是可靠的。

RELIABILITY OF APPLICATION OF IHA METHOD TO DETERMINE CHEMOTHERAPY TARGETS OF SCHISTOSOMIASIS IN MODERATELY ENDEMIC AREAS OF LAKE REGION

Objective To analyze the reliability of application of IHA method to determine, chemotherapy targets of schistosomiasis in moderately endemic areas of lake region. Methods Around Dongting Lake areas, a total of 6 villages where schistosomiasis prevalence rate was in the range of 10% to 15% were selected for the study. Half of I7opulation in each village was annually screened by indirect hemagglutination assay (IHA ) and residents with positive titer l: 10 or over were accepted as chemotherapy targets. Chemotherapy effects were checked up by Kato-Katz method. Results 90' 7 % ~ 96. 1 % positive cases detected by Kato-Katz were in keeping with post tive ones determined by IHA. 80. 5 % and 77. 7 % of the co-positive cases by IHA and Kato-Katz in l997 and 1998 were reversed to negative by Kato-Katz in 1999. on the other side, 96. 4% to 98. 3% of the co-negative cases by IHA and Kato KaTz were still kept to negative by Kato-Katz. However, merely positive cases by Kato-Katz in 1997, the returning negative rate was 74.4% in l999. Conclusion IHA could include more than 90% of positive cases by Kato-Katz and a number of cases whose schistosoma eggs in stool could not he detected by Kato Katz. Hence the findings (both positive and negative ) detected by IHA were reliable.