2.4. Mapping

In order to map the sites where seropositive persons were detected, data were imported into ArcGIS v.9.3.1 (Esri, Redlands, CA, USA) (Mitchell, 2005). The following layers were implemented: (i) the location of the sites by transfer of the information from Google Earth; (ii) the digital elevation model using corresponding information from the Greek Databank of Hydrological and Meteorological Information (http://www.hydroscope.gr) that represents the relief of the Greek State at a scale of 1:50,000 (cell size 25 m × 25 m); (iii) the land cover of the area of focus using the CORINE Land Cover Program (http://www.eea.europa.eu/publications/COR0-land- cover); and (iv) the administrative division (NUTS 3) with the corresponding annotation of the areas.