Experimental schistosomiasis mansoni: I- effects of Biltricide and discotome of different intensities of infection

Biltricide [Bayer, Germany] and the Egyptian version Distocide [Eipico] were subjected to comparative study to evaluate their efficacy on experimental Schistosomiasis mansoni using different intensities of infection. 372 Albino mice were divided into 3 groups infected with 50, 100 or 150 cercariae. Seven weeks later each group was subdivided into control, Biltricide- or Distocide-treated subgroups. There were no significant differences between Biltricide and Distocide in different intensities of infection regarding all parameters [ova/g stool, liver and intestine 2 and 4 weeks post treatment [p >0.05]]. Oogram patterns showed reduction in the number of mature ova, increase of dead ova and disappearance of immature stages and distribution and number of worms and couples, which was more reduced 4 weeks post treatment. In conclusion, Biltricide and Distocide are equally effective irrespective to intensity of infection

Experimental schistosomiasis mansoni: II- efficacy of RO 15-5458 Hoffmann-la Roche on different intensities of infection

Efficacy of RO 15-5458, as an antischistosomal drug in a dose of 15 mg/kg body weight, has been evaluated on 370 infected mice at different intensities [50, 100, and 150 Schistosoma mansoni cercariae/mouse]. Praziquantel [Biltricide 2 x 50 mg/kg body weight], for comparison and a vehicle as control, were included in the study. At the 2nd week post treatment [post ttt] praziquantel gave better effect than that of RO 15-5458. However, at the 4th week, both drugs gave more or less similar results. RO 15-5458 showed significant reduction of fecal eggs of 97.3%, 96.7% and 94.6% in mild, moderate and heavy infections, respectively, versus control group [P <0.001]. It also decreased ova/g liver and intestine significantly [P <0.001]. Oogram patterns revealed that immature stages disappeared in light infection, but persisted in moderate and heavy infections, while Praziquantel was effective in all stages. Worm burdens decreased significantly [P <0.001] in mild [79%], moderate [91.6%] and heavy [89%] infections recording a significant difference [P <0.01] in heavy infection with Praziquantel which gave a better effect [93.0%]. Regarding hepatic shift, it reached 85% by the 4th week post ttt. So, RO 15-548 showed a higher antischistosomal efficacy in light and moderate infection than in heavy one. It may need a higher dose to be as efficient as Praziquantel. Furthermore, it might be a good substitute for Praziquantel when resistance developed in a certain endemic area