The influences of environmental factors on the spatial distribution of urinary schistosomiasis in Federal Capital Territory, Abuja, Nigeria, using Geographical Information System and Remote Sensing

Abstract

A study was conducted in the FCT, Abuja, to investigate the influences of environmental factors on the prevalence and distribution of urinary schistosomiasis, using the Geographic Information System (GIS) and Remote Sensing (RS). Prevalence data were derived from the survey of infection in school children in 83 primary schools between 2011-2013. Remotely sensed environmental data of altitude, rainfall, soil type, and Normalized Difference Vegetation Index (NDVI) were downloaded from the United States Geological Survey website hosting the Moderate Resolution Imaging Spectroradiometer (MODIS) data specific to the geo-location of prevalence data. The environmental data and prevalence data were processed and analysis in GIS using spatial intepolation and displayed as maps. The overall prevalence of the infection in the FCT was 14.8%. Soil type was the only significant environmental variable among the listed ones in the determination of the pattern of prevalence of urinary schistosomiasis in the FCT. These were then tested using the Logistic Binary Regression Analysis (Backward stepwise – Likelihood Ratio method) and the model correctly predicted the pattern of infection to the tune of 84% by identifying 84 schools harbouring infected pupils using the equation p =1/1+e-z where p is the probability of finding infection in the FCT and z=1.030 + (1.204 x Soil type). The result of this study showed that among the three soil types plinthosol, lixitol and leptosol, plinthosol was a major determining factor in the prevalence of urinary schistosomiasis in the FCT.

Keywords: Geographic Information System; Remote Sensing; schistosomiasis; mapping; Nigeria.