Fig. 1From: Monitoring sick leave data for early detection of influenza outbreaksIncidence of influenza-like illness and sick leave in Ile-de-France. Incidence per 100,000 per week of influenza-like illness and sick leave in Ile-de-France, the most populous region in France, 2010–2017. Christmas and summer school holidays (increased worker leave periods) are shown at the bottomBack to article page