Geographical information systems (GIS) and risk maps of urinary schistosomiasis in Ogun State, Nigeria

Abstract

Remotely-sensed environmental images and geographical information system (GIS) are used to develop risk maps of the probability occurrence of urinary schistosomiasis and population at risk in Ogun State, Nigeria. The model was developed using Arc View GIS 3.2a Software and incorporating infection, population, rainfall, vegetation, temperature, soil-types, altitude, and school locations data. The resulting risk maps created suggested that urinary schistosomiasis is widely distributed, occurring in all the local government areas in the state. The high-risk areas (≥ 50% prevalence) were confined to foci in the
north-western part of the state. The models correctly predicted both the presence and absence of infection, the probability risk at any locality in Ogun State, as well as estimating the population at risk. The model estimated that 98.99% of school-aged children in the state are living in urinary schistosomiasis-suitable areas and are at risk of infection. As such, necessary preventive measures should be incorporated into water resources, projects, which are known to promote urinary schistosomiasis transmission. This investigation provides for the first time, detailed and comprehensive maps of the distribution of urinary schistosomiasis in Ogun State, which would help guide control efforts.

Keywords: GIS, risk maps, urinary schistosomiasis, school children, Ogun State.

Nigerian Journal of Parasitology Vol. 29 (1) 2008 pp. 42-49