Poor patient compliance reduces the efficacy of metrifonate treatment of Schistosoma haematobium in Somalia.

The degree of compliance during metrifonate therapy of Schistosoma haematobium infection has been evaluated together with its impact on drug efficacy in two rural villages in Somalia. Drug treatment was offered to all subjects with S. haematobium infection. 243 subjects were screened for the presence of eggs in the urine using a sensitive Nucleopore filtration method and 211 were positive. All infected patients were put on a treatment schedule of 3 doses of metrifonate 7.5 mg/kg at fortnightly intervals. Drug efficacy was evaluated 6, 12 and 32 weeks after treatment. Only 48% of the patients took all 3 doses, 15% took 2 doses and 37% only took 1 dose. The cure rate was maximal in Week 6 at 60, 44 and 30% in those who took 3, 2 and 1 dose, respectively. Corresponding egg reduction rates were 98, 90 and 84%, respectively. Drug efficacy throughout the follow up period was much greater in patients who complied with all 3 doses. It is unlikely that the goal of mass treatment programmes for endemic S. haematobium in villages in Africa will be realized due to poor compliance with the current dosage schedule for metrifonate of 3 doses of 7.5 mg/kg at fortnightly intervals.