Wide-scale installation of insecticide-treated curtains confers high levels of protection against malaria transmission in a hyperendemic area of Burkina Faso

In a region of Sudanese savannah in Burkina Faso, insecticide-treated curtains were installed in 8 out of 16 zones, each covering an area of about 50 km(2). Longitudinal entomological monitoring using CDC light traps was performed in 4 villages (2 intervention, 2 control) over a period of 3 years (including I year prior to intervention). In the 3rd year a cross-sectional entomological survey using spray catches was performed in 84 villages (40 intervention). Indoor vector densities in protected houses showed large reductions (P = 0.01). The available data were also consistent with an impact on outdoor and unprotected indoor densities. The proportion of mosquitoes carrying sporozoites was 4.1% in protected villages compared with 11.5% in unprotected villages (P = 0.07). Entomological inoculation rates fell substantially (P = 0.01), reflecting these reductions. The impact of this intervention on mosquito survival appears to have been greater than those in similar trials conducted in the Gambia, Ghana and Kenya in which the intervention was applied over smaller areas.