Communicable Disease Control in the Australian Capital Territory

Abstract

The ACT Health, Communicable Disease Control Section (CDCS) is responsible for the surveillance, investigation and public health management of notifiable diseases in the Australian Capital Territory (ACT). In this thesis, I present work conducted as a Master of Philosophy in Applied Epidemiology (MAE) scholar, whilst placed at the CDCS for the period of 2016–2017. During my placement, I was involved in routine disease surveillance and investigation activities on a daily basis, and completed the competencies aligned with the MAE program.

One such requirement is the analysis of a public health dataset. In the ACT notifications of influenza has increased in recent years. To better understand the epidemiology of influenza in the ACT, I analysed influenza notification and test data over an 11-year period. The analysis confirmed increases in notifications, and tests were independent of increases in test positivity. Findings also identified differences in case characteristics and the positive test rate, depending on the testing pathology laboratory. The analysis supports the recommendation that influenza surveillance in the ACT would be strengthened by introducing negative test reporting.

For my epidemiological study I present a time series analysis of different temperature metrics and notifications of enteric disease in the ACT. Associations better temperature and salmonellosis and cryptosporidiosis notification incidence were found using different metrics of temperature. These Findings were consistent with previous research for all diseases; and comparison of different temperature metrics suggest a temperature measure accounting for recent past temperature trends may be a useful predictor of enteric infection.

During my placement in CDCS – the section responsible for conducting outbreak response, most commonly foodborne - offered me multiple opportunities to meet the outbreak investigation MAE requirement. Here, I present an outbreak of Salmonella Typhimurium associated with a Canberra café where two waves of cases with distinct MLVA profiles were identified. The epi-curve suggested an intermittent exposure source over multiple weeks and a case-control study and environmental investigated indicated wide spread contamination of the café as the cause of the outbreak. In the appendices to this bound volume I also present two additional outbreak investigations from my placement. An acute response case-series investigation of gastroenteritis in a visiting school group from Queensland focused on detailing illness characteristics to inform public health decision making in lieu of pathology testing. And an cohort study following a report of multiple cases of acute gastroenteritis of unknown aetiology in people who attended a wedding. The investigation hypothesised person-to-person transmission to likely be the source after no food items were found to have a significant association with illness.

In the final chapter, for my evaluation project, I present an assessment of varicella zoster virus (VZV) surveillance in the ACT. Considering the introduction of the National Shingles Vaccination Program in late 2016, prompted the evaluation to measure the system’s performance. As part of the evaluation, I identified deficiencies in the system that could be readily overcome to improve the quality of surveillance undertaken in the ACT and presented recommendations to improve surveillance effectiveness moving forward.

Overall this bound volume is representative of two years of learning and skill development, providing documentation of my MAE placement at ACT Health and my contributions to the territory’s public health system, community and research. Show more