ABSTRACT
Maps provide an efficient and unique method of demonstrating distributions of phenomena in space. In 1849 Shapter published a book which included a dot map of the distribution of deaths caused by cholera in Exeter from 1832 to 1834. A. T. A. Learmonth, well known for his medico-geographical studies in India and Pakistan, evolved an ingenious method of plotting on the same map health or disease data concerning both intensity and variability of incidence. Programmes such as SYMAP developed at the laboratory for Computer Graphics and Spatial Analysis of Harvard University in 1965 played instrumental roles in introducing health professionals to the great potential of computer mapping. Maps are also used to demonstrate the spatial diffusion of communicable diseases. The mapping of disease and the analysis of geographical variations and meaningful spatial patterns of disease afford a valuable contribution to the detection of the causes of those diseases whose aetiology is as yet unknown.
