血吸虫病控制后检测循环抗原和抗体比较研究

目的在已达到国家血吸虫病传播控制标准后,选择一种更有效的、准确的诊断方法用于血吸虫病传染源的监测,巩固已取得的防治成果。方法用检测血吸虫循环抗原(ScAg)和检测血吸虫抗体(ScAb)的几种常用方法,对历史疫情较重,现已达到传播控制的流行村作平行检测,与历史检测结果作比较研究,并以病原学检查的毛蚴孵化法和Kato-Katz法检查对照。结果应用皮内反应试验(SK)检测皮肤型IgE抗体阳性率为22.6%和20年前(1985)检测阳性率23.5%比较,差异无统计学意义(P>0.05),用间接血凝法(IHA)检测SK试验阳性者为25.5%与过去(1985)检出阳性率29.1%相比,降低较少,酶免疫试验(ELISA)检测抗体仍有28.6%的阳性;采用一步酶免疫法(EIA)检测血吸虫循环抗原(ScAg),对粪检阳性的血吸虫病患者和正常健康人血清的有效诊断率达96.0%,平行检测上述血清阳性率为6.5%,与控制前(1998)的22.2%相比下降15.7%(P<0.01),而经粪检查出阳性的3例均在ScAg检出阳性者之内。结论检测血吸虫皮肤型IgE的SK只能反映历史的流行状况,检测血吸虫ScAb的IHA、ELISA,在反复化疗取得防治成效的流行区只能反映既往感染情况,特异性低,粪便检查受排卵因素影响漏检率高,检测血吸虫ScAg准确性高又能反映治疗后的效果,适合血吸虫病传播控制后用于疫情监测及传染源控制的有效查病方法。

Surveillance Effect by Detecting ScAg or ScAb after Schistosomiasis Transmission Being Controlled

Objective To select more effective diagnostic method for schistosomiasis reservoir surveillance after the disease transmission being controlled so as to consolidate the control effect.Method Several common diagnostic methods for detecting schistosome circulating antigen or antibody were parallelly applied in a historical hyper-endemic village but now the schistosomiasis transmission has been controlled.The results were compared with etiological hatching and Kato-Katz methods and historical diagnostic data.Result The positive rate of intradermal reaction rate(22.6%) showed no significant differences(P>0.05) with historical data(23.5%) in 1985.The positive rate of IHA in skin test positives was 25.5% which lowed a little than that(29.1%) in 1985.ELISA for detecting antibody still reached a positive rate of 28.6%.The positive rate of EIA,a method for detecting ScAg and with effective diagnostic rate of 96.0% to both stool positives or normal individuals was only 6.5% which lowed 15.7% as compared with 22.2% in 1998(P<0.01),and 3 cases positive in stool examination were also positive in EIA.Conclusion Skin test could only reflect historical epidemiological situation.IHA and ELISA in endemic area with better control effect after being carried out repeated chemotherapy could reflect the past infection situation.Because of many factors,stool examination had higher misdiagnostic rate.EIA for detecting ScAg showed higher accurancy and could reflect the control effect after chemotherapy,so it is a better method for disease surveillance and reservoir control in areas after schistosomiasis transmission being controlled.