Flutracking weekly online community survey of influenza-like illness annual report 2011 and 2012.

Flutracking is a national online community influenza-like illness (ILI) surveillance system that monitors weekly ILI activity and field vaccine effectiveness (FVE). This article reports on the 2011 and 2012 findings from Flutracking. There was a 22% increase in participants to 16,046 who completed at least one survey in 2012, compared with 2011 (13,101). By October 2012 (the end of the 2012 season), 54.2% of participants had received the 2012 seasonal vaccine, while by the end of the 2011 season, 55.9% of participants had received the 2011 seasonal vaccine. From 2007 to 2012 the FVE calculation for New South Wales participants demonstrated that the seasonal vaccine was effective except in 2009 when a novel H1N1 virus was dominant. The 2012 Flutracking ILI weekly incidence peaked in mid-July at 4.9% in the unvaccinated group, 1 month earlier than laboratory confirmed influenza. The 2011 Flutracking ILI weekly incidence peaked in mid-August at 4.1% in the unvaccinated group, 1 week later than laboratory confirmed influenza. Similar to laboratory notifications, there was an increase in ILI activity from 2010 to 2012, with the peak weekly ILI prevalence for 2012 Flutracking data, (unstratified by vaccination status), being higher (4.7%) than the peak weekly prevalence for 2011 (3.8%) and 2010 (3.7%). The 2012 Flutracking influenza season showed moderate levels of ILI, compared with lower levels of ILI seen in 2011 and 2010, and consistent with the increase in national influenza laboratory notifications.