Figure 3

Illustration of the different phases of a dengue outbreak and different levels of response. An example of an outbreak curve from Colombia in 2009 is shown here. An ‘outbreak alert’ is identified early through a combination of ‘alert signals’, and triggers an ‘initial response’. The evolution into ‘early’ and ‘full outbreaks’ are detected early using standard definitions and trigger appropriately staged ‘early’ and ‘emergency responses’.