日本血吸虫病常用诊断方法现场查病效果的评估

目的 评估几种常用血吸虫病诊断方法现场查病的效果。 方法 2005年11月，选取江西省鄱阳湖沿岸3个血吸虫病流行村的6~65岁居民为调查对象，用改良加藤厚涂片法（Kato-Katz法， 3张涂片）和尼龙绢集卵孵化法进行病原学检测的同时，分别用胶体染料试纸条法（DDIA）、快速酶联免疫吸附试验（F-ELISA）及2种间接红细胞凝集试验（IHA-A和IHA-B）进行血清学检测，以评价该几种检测方法的效果。 结果 3村共检测居民1 864人，平均粪检阳性率为9.7%。改良加藤法在血吸虫病中度、重度流行区的漏检率相对稳定，为20.0%~27.8%；尼龙绢集卵孵化法的漏检率在每克粪便虫卵数（EPG）＞100时相对稳定（约25％）。DDIA、F?鄄ELISA、IHA?鄄A和IHA?鄄B的平均阳性率分别为47.8%、50.0%、66.3%和40.1%。以病原学检测结果为金标准，DDIA、F?鄄ELISA、IHA-A和IHA-B的敏感性分别为75.3％、65.8％、85.6％和76.0%；特异性为55.1％、51.7％、35.7%和63.6％。与其他几种免疫血清学诊断方法相比，IHA?鄄B试剂的特异性、Youden指数、阳性似然比及粪检符合率最高。DDIA法与IHA-B法的符合率最高（77.3％），而F-ELISA和IHA-A的符合率最低（61.5％）。 结论 在血吸虫病中、重度流行区，改良加藤法虫卵检出率和稳定性均优于尼龙绢集卵孵化法；IHA-A的敏感性最高，IHA-B的4个指标最高，具有较高的现场使用价值，但需进一步提高其敏感性。

Effectiveness of Routinely Used Assays for the Diagnosisof Schistosomiasis japonica in the Field

Objective To evaluate the effectiveness of routinely used assays for schistosomiasis diagnosis in the field. Methods From late November to early December 2005, 6-65 years old inhabitants from 3 endemic villages were examined by Kato-Katz technique (3 thick smears) and nylon bag sedimentation/hatching method. At the same time, dipstick dye immunoassay(DDIA), fast enzyme linked immunosorbent assay (F-ELISA), indirect haemagglutination test A (IHA-A) and B ( IHA-B) were carried out in parallel. Results 1 864 people were examined by stool examination with an average positive rate of 9.7%. The missing rate of DDIA was relatively stable in medium and heavily endemic areas of schistoso-miasis. The missing rate of nylon bag sedimentation/hatching method was 25% and relatively stable when the number of eggs per gram of feces(EPG) was larger than 100. The average positive rate of DDIA, F-ELISA, IHA-A and IHA-B was 47.8%, 50.0%, 66.3% and 40.1% respectively. Using stool examination as the gold standard, the sensitivity of DDIA, F-ELISA, IHA-A and IHA-B was 75.3%, 65.8%, 85.6% and 76.0%; and the specificity was 55.1%, 51.7%, 35.7% and 63.6%, respectively. Among the four sero-diagnostics, the specificity, Youden index, positive likelihood rate and coincidence of IHA-B were the highest. Conclusion Kato-Katz method is more stable and effective than nylon bag sedimentation/hatching method in medium and heavily endemic areas of schistosomiasis japonica. The sensitivity and spec-ificity of these four diagnosis kits are lower than 90%.