Efficacy and cost-effectiveness of environmental management for malaria control

Roll back malaria (RBM) aims at halving the current burden of the disease b y the year 2010. The focus is on sub-Saharan Africa, and it is proposed to implement efficacious and cost-effective control strategies. But the eviden ce base of such information is scarce, and a notable missing element is the discussion of the potential of environmental management. We reviewed the l iterature and identified multiple malaria control programmes that incorpora ted environmental management as the central feature. Prominent among them a re programmes launched in 1929 and implemented for two decades at copper mi ning communities in Zambia. The full package of control measures consisted of vegetation clearance, modification of river boundaries, draining swamps, oil application to open water bodies and house screening. Part of the popu lation also was given quinine and was sleeping under mosquito nets. Monthly malaria incidence rates and vector densities were used for surveillance an d adaptive tuning of the environmental management strategies to achieve a h igh level of performance. Within 3-5 years, malaria-related mortality, morb idity and incidence rates were reduced by 70-95%. Over the entire 20 years of implementation, the programme had averted an estimated 4173 deaths and 1 61205 malaria attacks. The estimated costs per death and malaria attack ave rted were US$ 858 and US$ 22.20, respectively. Over the initial 3-5 years s tart-up period, analogous to the short-duration of cost-effectiveness analy ses of current studies, we estimated that the costs per disability adjusted life year (DALY) averted were US$ 524-591. However, the strategy has a tra ck record of becoming cost-effective in the longer term, as maintenance cos ts were much lower: US$ 22-92 per DALY averted. In view of fewer adverse ec ological effects, increased sustainability and better uses of local resourc es and knowledge, environmental management - integrated with pharmacologica l, insecticidal and bednet interventions - could substantially increase the chances of rolling back malaria.