Kato-Katz法诊断日本血吸虫病误判因素的研究

Study on the misjudgement factors for the diagnosis of Schistosomiasis by Kato-Katz

目的探讨并分析Kato-Katz法厚涂片中血吸虫卵误判的原因,为今后的血吸虫病查病工作提供帮助。方法对三个试验点的初查Kato-Katz法血吸虫卵阳性片随机抽查5%进行复核;观察Kato-Katz法血吸虫卵阳性片在不同温度和不同时间下虫卵的形态变化。结果三个试验点总的阳性符合率为86.09%,假阳性率为13.91%。随着温度和时间的变化,血吸虫卵的形态也发生改变。结论由于血吸虫卵在Kato-Katz厚涂片中的形态与水洗片中的标准形态差异较大,且受实验条件的影响,很容易造成误判,必须加强质量控制和技术培训。

Objective To study on the factors for the misjudement of S. japonicum eggs by Kato- Katz, and help for the examination of schistosomiasis. Methods 5% of the positive samples which detected by the Kato-Katz method were random sampled and re-checked in three sites. The morphological changes of S. japonicum eggs were observed sander different temperatures and times. Results The positive coincidence rate was 86.09% in the three sites, and the false positive rate was 13.91%. The morphological of S. japonicum eggs was changed with temperature and time. Conclusion S. japonicum eggs by Kato-Katz was likely to be mis- judged due to the large difference on the standard shape for S. japonicum eggs in the thick smear of Kato- Katz and washing smear. The judgement of S. japonicum eggs was also influenced by experimental conditions. Therefore, the quahty control and technical training should be strengthened as soon as possible.