Malaria outbreak control in an African village by community application of 'deet' mosquito repellent to ankles and feet

The malaria vector Anopheles arabiensis Patton (Diptera: Culicidae) shows a marked predilection (>80%) for biting the ankles and feet of human subjects, as revealed by our previous observations at Malahlapanga in the Kruger National Park, South Africa. Topical application of insect repellent, 15% deet (N,N-diethyl-3-methylbenzamide), to feet and ankles reduced the overall biting rate of An. arabiensis by 69%. A focal malaria epidemic in Albertsnek village (25degrees33' S, 31degrees59' E) near the Mozambique border, following flooding during February 2000, provided an opportunity to apply these findings of operational research for outbreak containment. Twice-nightly topical application of deet to ankles and feet of Albertsnek inhabitants was followed by rapid restoration of pre-epidemic malaria incidence levels after one incubation period. This encouraging outcome should be attempted in other outbreak-prone settings where infective mosquito bites are sporadic and malaria has unstable endemicity.