TEMPORAL DIFFERENCES IN PRAZIQUANTEL-INDUCED AND OXAMNIQUINE-INDUCED TEGUMENTAL DAMAGE TO ADULT SCHISTOSOMA-MANSONI - IMPLICATIONS FOR DRUG-ANTIBODY SYNERGY

A temporal study of the effects on the tegument of Schistosoma mansoni adult worm following in vivo praziquantel and oxamniquine treatment w as performed. Drug-induced damage to the tegument, exposure of surface antigens and attachment of host antibody occurred rapidly, within 1 h , following praziquantel treatment. Oxamniquine-treated worms required 4-8 days for these effects to be apparent. The 2 drugs differed in th e degree and sites of damage on the worm surface. The administration o f 2 different polyspecific rabbit sera with drug significantly increas ed the efficacy of praziquantel when administered with the drug, but n ot when given 6-9 days after drug treatment. In contrast, only 1 serum was synergistic with oxamniquine when administered with drug and both sera were synergistic when given 6-9 days after drug treatment. The e ffect of immune killing of drug-treated worms is discussed.