Figure 2. The number of cases by date of illness onset following the 2010 and 2011 triathlon competitions, Copenhagen.

Day of onset of illness for cases with known onset date following the 2010 competition (blue bars, n= 345), and the 2011 competition (red bars, n=64). The 2010 competition took place on 15 August (blue arrow) and the 2011 competition on 14 August (red arrow).