Fig. 1

Map of Greater Accra region, Ghana showing study and other districts (map drawn by authors). The pie charts represent frequency of distribution of mutant alleles in each study site. The study districts were Accra Metropolis (5° 33′ 0″ N, 0° 12′ 0″ W), Ga West Municipal (5° 42′ 9″ N, 0° 18′ 0″ W), Ga South Municipal (5° 34′ 0″ N, 0° 20′ 0″ W), Ashaiman Municipal (5° 42′ 0″ N, 0° 2′ 0″ W) and Ada East District (5° 47′ 0″ N, 0° 38′ 0″ E)