Geospatial Modelling of Buruli Ulcer Prevalence in Amansie West District, Ghana

Buruli ulcer (BU) is a disease caused by mycobacterium ulcerans (MU). The large number of cases and the complications currently associated with the disease as well as its long-term socio-economic impact could have a substantial effect on the rural economy. Knowledge gaps about the exact mode of transmission and factors that pre-dispose to infection motivated this study. This study employed geographical information systems (GIS) and geostatistics to establish relationship between BU and postulated risk factors in Amansie West District of Ghana. Semivariograms were computed to determine the strength and spatial dependency of the pattern of disease as well as summarize the variation. The risk of developing the disease was estimated by kriging. Ordinary kriging was chosen in the variogram modeling. The BU data sets exhibited a highly positively skewed histogram with possible outlying. The length of spatial autocorrelation (practical range) was much longer than sampling interval (lag size).The kriged map showed that there are large patches of BU disease in the southern part of the study area with few isolated cases in the other parts.. The research revealed that the disease is prevalent in the southern portion of the district which is drained by rivers Oda and Offin. The southern portion is also characterized by intense mining and agricultural activity. The paper concludes that intense human interaction with aquatic environment may be responsible for the high prevalence of BU in the District.