Weekly influenza-like illness incidence rate (/100,000) according to Sentinelles network by age for the epidemic period of winter 2011–2012.

<p>yo: year-old. Source: réseau Sentinelles, INSERM/UPMC, <a href="http://www.sentiweb.fr" target="_blank">http://www.sentiweb.fr</a> Accessed 24 March 2015. Age is a risk factor for CRTI. The figure shows that the ILI incidence during the epidemic season (weeks 5 to 12 of 2012, during winter 2011–2012) is age-dependent. Children aged between 0 and 9 years have the highest incidence rates, up to 434 cases/100,000 at season’s peak.