粪抗原检测法诊断犬细粒棘球绦虫感染的研究Ⅱ.粪抗原检测的敏感性、特异性及实验感染犬排出粪抗原的动态观察

DIAGNOSIS OF ECHINOCOCCUS GRANULOSUS INFECTION IN DOGS WITH COPROANTIGEN DETECTION

用细粒棘球绦虫成虫虫体抗原及其抗体建立的双抗体夹心ＥＬＩＳＡ滴定成虫抗原的结果Ａ４５０值与抗原含量呈指数曲线关系，高度相关（ｒ＝０．９８）。实验感染家犬粪抗原含量在２．５－８．０μｇ／ｍｌ之间，因此本法在检测粪抗原中具有足够的敏感性。家犬泡状带绦虫的感染引起的交叉反应是影响本法特异性的主要问题。选择最适的抗体包被浓度可消除交叉反应。用细粒棘球蚴原头节感染家犬后，粪抗原呈低滴度阳性，至２１天后迅速升高。实验感染泡状带绦虫的家犬观察５０天粪抗原均在临界水平之下。作者推荐本法可用于家犬细粒棘球绦虫成虫感染的诊断。

A double antibody sandwich ELISA developed with the somatic antigen of E.granulosus adult worm and antibody system were used in antigen titration.The A450 values correlated with concentrations of antigen by an exponential curve.Coproantigen contained in feces of infected dogs were 2.1-8.0g/ml,therefore this method possess sufficient sensitivity for detection of coproantigen.The cross reaction were found in fecal samples of T.hydatigena infected dogs and this cross reaction could be eliminated by selection of optimal concentration of coating antibody.A low titre of coproantigen were found in feces ofter experimentally infection of dogs and elevated markedly at the 21th day.The authors recommanded this method to apply in coproantigen detection for diagnosis of E.granulosus infection in dogs.