Retrospective analysis done during the past 30 days before the event was officially reported showed that EDE Alerts were already triggered as early as 30 days (median of 27.5 and range 14Á30 days) prior to the date of the NEC report. The number of days associated with EDE 'alerts' out of the 30 days prior to the NEC official report date had a median of 9.5 days (range of 3Á14 days). A total of 17 municipalities had reported dengue cases above the alert or epidemic threshold with 8/17 of these municipalities having at least 1 day in the previous week with a case count of more than 5 while 9/17 had case counts of 5 or less for all 7 days in the past week. For municipalities with at least 1 day with a case count of 5 or more for the previous 7 days, the median of the number of days with associated EDE alerts was 5 (range 0Á7 days). For municipalities with case counts of 5 or less for all 7 prior days, no alerts were usually generated (median 0 and range 0Á2 days).