ABSTRACT
The representation and analysis of maps of disease-incidence data is a basic tool in the analysis of regional variation in public health. The development of methods for mapping disease incidence has progressed considerably in recent years. One of the earliest examples of disease mapping is the map of the addresses of cholera victims related to the locations of water supplies by John Snow in 1854. In that case, the street addresses of victims were recorded and their proximity to putative pollution sources (water supply pumps) was assessed (Snow, 1854).
