Coproantigens: early detection and suitability of an immunodiagnostic method for echinococcosis in dogs

In the present study immunodiagnostic tests for Echinococcus granulosus-specific coproantigens have been evaluated. The techniques are based on polyclonal antisera collected from dogs experimentally infected with E. granulosus protoscoleces. ELISA, Countercurrent immunoelectrophoresis (CCIEP) and Immunodot were evaluated for their application in coprodiagnosis. The level of coproantigens was detectable on day 7 post-infection and reached a maximum level on day 56 as detected by ELISA. Very high O.D values were obtained when faecal samples of 7-8 weeks post-infection were used. Besides this, immunodot and CCIEP were also tested and the 4th week post-infection samples gave significant reactions. It is evident from the results that ELISA was more sensitive and detected the coproantigens as early as the first week post-infection whereas immunodot and CCIEP detected coproantigens later. The latter methods are rapid, cost-effective and can be used to diagnose suspect cases of echinococcosis under field conditions. Thus, it is suggested that future studies should be aimed at early detection of echinococcosis by a rapid and cost-effective immunodot test.