The cost effectiveness of mass drug therapy for intestinal helminths.

This article reviews the principles involved in establishing the cost effectiveness of mass drug therapy for the major intestinal nematodes and the intestinal form of schistosomiasis, as well as the extent to which the available studies have provided definitive answers. For governments or agencies that have decided to introduce a control programme, there is considerable evidence about the comparative cost effectiveness of different types of delivery strategies. For example, mass treatment is more cost effective than selective treatment (treatment after individual screening) in high prevalence areas and at observed prices. Mass treatment targeted at known high risk groups, such as schoolchildren, for the major intestinal helminths (apart from hookworm) can be more cost effective than population-based mass treatment. However, this raises the question whether any form of mass anthelmintic chemotherapy is an efficient use of scare health resources in view of the competing demands for scarce public funds, and for the scarce resources of other funders of healthcare including donors, nongovernmental organisations and missions. Some evidence that it is an efficient use of resources is available; this article concludes by outlining the type of information that is required to strengthen the argument for mass therapy.