Abstract: AIM: To observe the dynamic changes and disappearance of three kinds of schistosome
circulating antigens(CAgs) in infected rabbits before and after praziquantel treatment. METHODS:
Dot ELISA assays were developed by using 3 McAbs to determine the dynamic changes of the gut
associated antigen(GAA), membrane associated antigen(MAA)and soluble egg antigen(SEA)
respectively in sera of rabbits infected with S.japonicum. RESULTS: By the 4th week after
infection 39% of the rabbits infected with S.japonicum were GAA positive and only 8.6% were MAA or SEA positive. All the infected rabbits become positive with GAA, MAA and SEA by the 8th week after infection. The titers of the GAA, MAA and SEA in sera of the infected rabbits reached their peaks by the 10th week after infection. Titers from rabbits of the untreated group rabbits remained high level until the 27th week after infection. SEA titers were found negative in 10% of the inffected rabbits in the treatment group by the 6th week after treatment. The titers of GAA of, MAA’ and SEA were found negative in 20%, 80% and 70% of the rabbits in the treatment group, respectively, the 8th after treatment. GAA, MAA and SEA in sera except one of the treated rabbits were all negative by the 14th week after treatment. CONCLUSION: The determination of GAA is useful for the early diagnosis of schistosomiasis, while the determination of, MAA and SEA might be used for the efficacy evaluation.

Key words: Schistosoma japonicum, circulating antigen, dynamic observation, efficacy evaluation