Cluster size for the different epidemics. Time has been rescaled and π represents the Fall peak and 3π the Spring peak. Cluster Size for cases is shown in (a) and cluster size for cases-water in (b) Different symbols represent different epidemics a temporal window of 5 days for the disease data was used for this figure, but see additional figures for a disaggregation for the different epidemics and temporal windows. In (a) the occurrence of small clusters is clearly abundant, moreover medium size clusters (less than 6 Km) are less abundant and bigger clusters are rare, this pattern is not clear for (b). In addition, clusters clearly occur more often in the Fall peak and in the Spring.