Disease may be taken as some degree of failure by the organism to challenges posed by the internal or external environments or both. Among populations, the degree of failure to adjust to some of these challenges is reflected crudely by morbidity and mortality indices reflect variations in space and time. The spatial distribution of morbidity and mortality is often non-random and many of the Ivariables in the external environment which are hypothesized as challenges to health also follow non-random spatial distributions. Geographical environment which is a complex web of land, air, water and socio-economic conditions of the society is therefore an over-riding factor in the dispersal and diffusion of diseases in a variety of ways and thus needs a careful examination and analysis in portraying the disease distribution patterns in time and space.

Keywords: Morbidity, Mortality, Spatial Distribution, Geographical Environment.