Flutracking: a weekly Australian community online survey of influenza-like illness in 2006, 2007 and 2008.

Surveillance for influenza is an important public health function as it allows initiation and evaluation of public health measures. Flutracking is a weekly online survey of influenza-like illness (ILI) completed by community members that has been trialled in the 2006, 2007, and 2008 winter influenza seasons. The online survey allows participants to record their past and current influenza immunisation status and they receive a weekly email prompt to answer questions on the previous week's experience of cough, fever and time absent from normal activities. The weekly survey takes participants less than 15 seconds to complete. Symptom rates of Flutracking participants were compared by influenza vaccination status to estimate the incidence and severity of influenza and the field effectiveness of influenza vaccine. Participation rates increased from 394 in 2006 to 982 in 2007 and 4,827 in 2008. In 2008, 56% of participants were from New South Wales and 26% were from Tasmania. Greater than 70% of respondents replied within 24 hours of the survey being sent in 2007 and 2008. The 2008 influenza season appeared milder than 2007 with the peak weekly rate of cough and fever among all unvaccinated participants at 7% in 2008 compared with 15% in 2007. The peak week of influenza activity detected by Flutracking in 2008 was the week ending 31 August, which was contemporaneous with the peak week in other syndromic and laboratory influenza surveillance systems. Participation in the survey continues to grow and appears sustainable. A more balanced recruitment across jurisdictions will provide a more national perspective.