Urinary schistosomiasis treatments

Cochrane review confirms evidence and identifies gaps

TDR news item
13 August 2014

A review of treatments for urinary schistosomiasis finds a strong evidence base for the use of praziquantel and outlines future studies needed to determine whether combination treatments could be useful. This is a new edition of a Cochrane review first published in 1997 to evaluate the efficacy and safety of drugs for this disease.

Urinary schistosomiasis is a disease caused by parasitic worms which, if left untreated, can eventually lead to anaemia, malnutrition, kidney failure, or bladder cancer. The disease occurs mainly in school-aged children and young adults in sub-Saharan Africa.

The review of 30 randomised controlled trials enrolling over 8,000 subjects found that the World Health Organization recommendation to use praziquantel at 40 mg/kg is supported by high-quality evidence; this regimen cures on average around 60% of people and reduces the number of schistosome eggs in the urine by over 95%, at one to two months after treatment.

The review found that praziquantel is the most studied drug for treating urinary schistosomiasis and has the strongest evidence base that proves its effectiveness. However, at present, praziquantel is the main drug for treatment, and like all single treatments against parasites, is at risk of having the worms develop resistance to long-term use. Beyond praziquantel, few other treatments have been studied for urinary schistosomiasis. Metrifonate, which is not available today, appears to be effective, but evidence is less strong. Inconsistent results were obtained with the antimalarial drugs artesunate and mefloquine.

Implications for research

The authors, including TDR’s leader of intervention and implementation research Piero Olliaro, say dosing regimens for young children and incremental benefits of drug combinations should be studied further in rigorous, adequately powered trials using standardized outcome measures. The authors write that it is important and urgent that these parameters be agreed upon and applied.

For more information, contact:

Piero Olliaro (olliarop@who.int)