Can source reduction of mosquito larval habitat reduce malaria transmission in Tigray, Ethiopia?
The development of irrigation schemes by dam construction has led to an increased risk of malaria in Tigray, Ethiopia. We carried out a pilot study near a microdam to assess whether environmental management could reduce malaria transmission by Anopheles arabiensis, the main vector in Ethiopia. The study took place in Deba village, close to a dam; Maisheru village, situated 3-4 km away from the dam, acted as a control. Baseline entomological and clinical data were collected in both villages during the first 12 months. Source reduction, involving filling, draining and shading of potential mosquito-breeding habitats was carried out by the community of Deba in the second year and routine surveillance continued in both villages during the second year. Anopheles arabiensis was highly anthropophilic (Human Blood Index=0.73), biting early in the night before people went to bed. The major breeding habitats associated with the dam were areas of seepage at the dam base (28%), leaking irrigation c