Comparison of the effects of praziquantel and metrifonate treatment in schistosoma haematobium (mazeras strain) infection in hamsters

Abstract

Schistosomiasis is the second most important parasitic infection, after malaria, mainly infecting poor people in the tropics who can hardly afford the cost of the currently available drugs for treatment. Consequently, sub-curative doses to reduce morbidity while maintaining compatibility with the low economic status of the patients have been advocated. However, it has not been shown that sub-curative doses directly reduce morbidity, owing to ethical reasons. This study investigated the effect of praziquantel and metrifonate therapy on proliferative responses to schistosome antigens, histopathology and worm density in the Syrian golden hamsters infected with Mazeras strain of Schistosoma haematobium. The hamsters were infected with Mazeras strain of S. haematobium and then treated with two doses of either 200 mg/kg body weight metrifonate (n = 32) or 500 mg/kg body weight praziquantel (n = 32). Then their in vitro proliferative responses to schistosome antigens, pathology and worm reduction were compared. Both lymph node and spleen cells from both .treated and untreated hamsters showed increasing proliferative responses to schistosome antigens SSP, SWAP and SEA. No granulomas were observed in the livers of praziquantel-treated hamsters. Both metrifonate-treated and untreated hamsters had schistosome-egg-related granulomas 1, 3 and 7 weeks after treatment. No worms were recoyered from praziquantel-treated hamsters. There was a significant statistical difference between the number of worms recovered from metrifonate-treated hamsters and those from untreated hamsters in the first 3 weeks after treatment (p< 0.05). However, 7 weeks after treatment there was no significant difference (p > 0.05) between the numbers of worms recovered from these latter two groups of hamsters. These results suggest that praziquantel is more effective than metrifonate in the management of Mazeras strain of S. haematobium infections