Summary
Spatial analysis is making an increasingly important contribution to surveillance measures due to its ability to enable immediate visualization of information on the phenomenon studied. The authors describe the spatial distribution of prevalence and incidence of brucellosis in small ruminants in Sicily between 2001 and 2005. The study was conducted by integrating geographic information systems (GIS) technology (MapInfo Professional 7.0) with SaTScan™ software to perform an epidemiological analysis of the municipalities and to locate problem areas. A comparison between the thematic maps produced for brucellosis in small ruminants on the basis of prevalence and incidence data for each individual year has shown that in terms of prevalence, the area identified as the secondary cluster in 2001 became the primary cluster from 2002 onwards whereas, in terms of incidence, the distribution of the clusters was irregular throughout the entire region during the years studied.

Keywords
Brucellosis, Geographic information system, Incidence, Prevalence, Sicily, Small ruminant, Spatial analysis.