The effect of size of surface drinking water sources on dracunculiasis prevalence in the Northern Region of Ghana

Abstract

The effect of the size of surface drinking water sources on the prevalence of dracunculiasis was investigated in two villages (total population 6122) in the Northern Region of Ghana. Cross-sectional house-to-house surveys were carried out during 1990 and 1991 to assess dracunculiasis prevalence and the use of different water sources. Distances to water sources used by the households were measured. During 1990, in Tali village, inhabitants who lived far from the dam and had used water from small ponds nearby for drinking in the previous year, had a high dracunculiasis prevalence. It increased with distance and reached 19.5% for those over 2500 metres away from the dam. Dam users (inhabitants living less than 500m from the dam) had a lower dracunculiasis prevalence (5.6%). All the small ponds dried up in 1990; Guinea worm infection was independent of distance in 1991, and reflected the prevalence among dam users (5.4%). In another village, Tolon, the use of water from a small dam, which dried up in the mid 1990 dry season, was associated with a high prevalence of dracunculiasis in the following year (10.6%), while use of a relatively large dam that lasted all year round was associated with significantly lower dracunculiasis prevalence (6.6%). The findings of this study shed light on the impact of water sources with different capacities on dracunculiasis prevalence, and support the theoretical reasoning that small water sources are a greater health hazard than larger ones.