Seasonally as a determinant of the efficacy of praziquantel in population based chemotherapy: lessons from the practice

ABSTRACT

During October-November 1991, 1356 male farmers, 18-40 years old from a village in Fayoum Governorate, Egypt, were examined for Schistosoma hematobium infection. The prevalence of infection was 22.2%. Infected farmers were treated immediately with Praziquantel at the recommended dose of 40 mg/kg body weight in a single, oral dose. 12 weeks after treatment, 86/262 infected farmers were negative for S. hematobium eggs in urine. In another study conducted in a satellite village in the Nile Delta [Behaira Governorate], where S. mansoni infection is prevalent, all residents of both sexes between 5 and 50 years of age [n = 858] were examined for S. mansoni. The prevalence of S. mansoni was 69%. Infected subjects were treated with the same dose of Praziquantel during January-February 1994, with an overall resultant efficacy of 85.5% [471/551] and 97.2% [103/106] in 18-40 years old males 8-10 weeks post-treatment. The high cure rate in the second study was probably because treatment took place at 2 months after the end of the high transmission season