Creating a syndromic surveillance system

Abstract

This thesis is a summary of the work completed as part of the Masters of Applied Epidemiology (MAE) program at the Australian National University. The thesis is made up of 5 chapters, and 4 appendices that together describe all the work required to complete the MAE program.

My field placement was at Healthdirect Australia, which is a Council of Australian Governments (COAG) organisation that delivers a range of telephone and digital health and the last chapter details the measles investigation.

1.0.1 Chapter 2: Surveillance This chapter discusses a syndromic surveillance system for influenza-like illness created using the healthdirect helpline and the healthdirect online symptom checker data. I discuss the data sources used for the surveillance system, describe the epidemiology of influenza-like illness contacts, then evaluate the proposed system using the US Centres for Disease Control and Prevention Guidelines. I conclude that the proposed surveillance system has excellent representativeness and timeliness, and submit a dashboard that could be used to publish the system. However, weaknesses of the system are flexibility and sensitivity, which are due to the limited details collected on each call or visit.

1.0.2 Chapter 3: Data Analysis The data analysis chapter describes three projects undertaken to complement the creation of the surveillance system discussed in Chapter 2. The aims of these three projects were: to identify unusual activity in the data; to determine the correlation between Healthdirect Australia data sets with seven other data sets; and to establish a case definition that maximises correlation with other data sets. I find that the healthdirect helpline data correlates very well with other data sources, particularly with emergency department surveillance. I was also able to identify unusual behaviour during the 2009 pandemic year, and to identify the start and finish of an influenza season. I conclude that, due to the high degree of correlation between the Healthdirect Australia data and other data sources, this system could contribute to influenza surveillance in Australia by improving knowledge about the community level of disease.

1.0.3 Chapter 4: Epidemiology Project In this chapter, I further explore the work of the previous 2 chapters by expanding to 6 further syndromes. Two of these syndromes - adverse reaction following immunisation and gastroenteritis - demonstrated high utility if they were to be added to the proposed influenza-like illness surveillance system. The adverse reaction following immunisation syndrome data shows the ability both to detect a spike in activity, and also to mirror the epidemiological characteristics known about the event. The healthdirect helpline data for gastroenteritis demonstrates similar behaviour to gastroenteritis visits to the emergency department. On the other hand, an investigation into geographical variations in gastroenteritis did not identify smaller regional outbreaks, nor did it show the geographical spread of illness. I conclude however that surveillance on both gastroenteritis and adverse reaction following immunisation could be useful to public health departments.

1.0.4 Chapter 5: Outbreak Investigation The final chapter discusses work conducted while on secondment at the Western Sydney public health department. My work here consisted of assisting in investigating a measles outbreak, which affected 17 people from March to April on 2017. In the chapter, I discuss the epidemiology of the outbreak and the public health resources committed to containing the outbreak, particularly through contact tracing. I conclude that responding to measles outbreaks pose a large burden on public health departments, particularly through extra staff hours. However, literature has shown that this effort does result in a significant reduction in secondary measles cases. Show more