Comparative Assessment of rEPC1 antigen and Copro-antigen for diagnosis of Echinococcosis in dogs

Diagnosis of Echinococcus granulosus in the definitive host particularly in dog is the significant complication in the endemic area.
The aim of this study is serological detection of E. granulosus in the infected dogs.
Dot-ELISA based on the copro-antigen and recombinant EPC1 antigen (rEPC1) for antibody detection was performed. Blood and fecal samples were collected from eleven treated poppies with 90000–100000 protoscoleces (90% viability) and four treated poppies with distilled water as controls, on day before challenge and 7, 14, 21, 28 and 35 days post challenges. Furthermore, the blood and fecal samples were collected from 35 naturally infected dogs.
In terms of experimentally infected dogs, sensitivity and specificity of Dot- ELISA were close for both antigens (copro- antigen, rEPC1) that were determined to be 100%, 88% for copro–antigen, and 100 and 94% for rEPC1, respectively. In the context of naturally infected dogs, our findings showed similar sensitivity in Dot –ELISA based on the anti-body detection (using rEPC1), and antigen detection (using copro–antigen), (100%), while these methods provided different specificity about 75% for rEPC1 and 58% for copro–antigen.
Our findings indicated that both antigens are qualified. REPC1 antigen is not capable to detect the infection during the first 15 days post-infection, whereas the antibody cannot be detectable. REPC1 protein may work for screening of E. granulosus, while copro-antigen can be useful for diagnosis of current acute infection. However, both methods are recommended for screening of sheepdog, guard dogs and police dogs.