Ninth meeting of the working group on monitoring of neglected tropical diseases drug efficacy

The Working Group on Monitoring of Neglected Tropical Diseases Drug Efficacy has developed a protocol to guide assessments of drug efficacy against both schistosomiasis (with praziquantel) and soil-transmitted helminthiases (with albendazole and mebendazole). It also recommends testing drug combinations and co-administering albendazole and mebendazole with ivermectin to contain the risk of emergence of resistance. Assessments are recommended in particular in areas where preventive chemotherapy programmes have attained a high coverage for more than 5 years. To date, more than 20 drug efficacy trials have been performed in 15 countries (Table 1). While in most countries no signs of resistance to praziquantel have been observed, in others reduced efficacy has been noted. For example, the mean Schistosoma mansoni egg reduction rate in schoolchildren in Uganda who had received 8 or 9 previous rounds of preventive chemotherapy was found to be significantly lower than the mean reduction rate in schoolchildren who had received 5 or a lower number of rounds of preventive chemotherapy (2). Similarly, in some countries, doubtful efficacy results have been reported for mebendazole against hookworm infections.

The objectives of the meeting were: