Flutracking Australia Influenza-like Illness Surveillance System: Evolution of methods from 2006-2016 (Preprint)
UNSTRUCTURED This paper documents the evolution of Flutracking from a pilot online influenza-like illness (ILI) survey of 394 participants in a local health region to a national surveillance system with over 30,000 participants in 2016. In 2018, there were over 40,000 survey responses per week in most weeks. In particular, this paper will describe how the methods have developed to meet the 1) changing aims of the system; 2) developing capabilities of the system; and 3) participant growth. The aim of this paper is to provide insights to other groups initiating participatory public health surveillance systems and to assist users of our data and reports to better understand Flutracking methods. Some of the key changes to Flutracking from 2006 to 2016 include: allowing participants to respond on behalf of other household members from 2008; adding health seeking behaviour questions in 2011; and offering an express survey and follow-up of unknown test results from 2016 onwards. The Flutracking system has demonstrated its ability to adapt to changes with minimal disruption to participants, and maintain consistency in data collection and reporting. As an example of success, Flutracking has been integrated in the Australian Government Department of Health’s regular influenza reports, and is now contributing weekly data to the transmissibility and impact measures for the Australian Government Department of Health’s application of the Pandemic Influenza Severity Assessment system. Flutracking data have consistently aligned with the timing of the peak level of influenza activity from other Australian influenza surveillance systems. Flutracking provided a unique insight into 2009 H1N1 influenza pandemic in 2009 demonstrating that the community level ILI attack rates were only slightly higher than 2008, and lower than 2007 in the community. Flutracking has demonstrated to be significantly less biased by treatment seeking behaviour and laboratory testing protocols than other surveillance systems during the 2009 influenza pandemic. In 2018, Flutracking expanded to New Zealand, with an average of over 2,800 surveys per week so far. The evolution of Flutracking’s methods has been pivotal to the success of this surveillance system.