Diagnosis of canine echinococcosis: Comparison of coproantigen detection with necropsy in stray dogs and red foxes from northern Jordan

The sandwich enzyme linked immunosorbent assay (ELISA) was used as a diagno stic test for Echinococcus granulosos infection by detecting coproantigens in 94 stray dogs Canis familiaris and eight red foxes (Vulpes vulpes) from northern Jordan. The results were analyzed in relation to actual helminth i nfection as revealed by necropsy. The infection rate of dogs with E. gronul osus was 13.8 % with a worm load ranging between 3 - > 10,000 per infected dog. In contrast, eight of 13 E. granulosus infected dogs were coproantigen positive (overall sensitivity 61.5 %). The sensitivity increased to 82.5 % and 100 % in dogs harboring > 20 and > 100 worms/dog, respectively. The sp ecificity of coproantigen-ELISA was 91 %. The greatest cross-reactivity was found in dogs infected with Dipylidium caninum. The positive and negative predictive values for the coproantigen-ELISA test were 50 % and 94.2 %, res pectively. Thus, a coproantigen negative dog is most probably truly negativ e for E. granulosus. In contrast, a coproantigen positive dog may not be tr uly positive for E. granulosus, except if it has a high worm burden of > 10 0 worms/animal.