ABSTRACT
We established in Chapter 2 that the basic working units of disease data in a GIS include point (e.g., patient location), line (e.g., transmission route), and area (e.g., disease rate by county). Among these three data units, point data representing disease locations are the basic and most fundamental in spatial epidemiological studies. Point pattern analysis in spatial epidemiology concerns the distribution of disease events in space. At the elementary level, the spread of a disease in a community is revealed through the plotting of disease occurrences (at the residential locations of infected individuals) enabled with the geocoding or address matching function in a GIS (see Section 2.4 of Chapter 2 for detail). Point-by-point plotting is the simplest form of mapping disease occurrences.
