Investigation and surveillance of infectious diseases

Abstract

In this thesis, I present selected works I conducted in my Master of Philosophy Applied Epidemiology (MAE) placement at the Vaccine Preventable Disease Surveillance (VPDS) Section of the Office of Health Protection (OHP), at the Australian Government Department of Health from March 2013 to November 2014. The works presented comprise my MAE requirements and describe my experiences as an MAE. I discuss my role in the day-the-day activities of the VPDS section, including the surveillance of notifiable diseases, being the secretariat for the rotavirus working group, writing annual reports and editing Communicable Disease Intelligence Journal submissions. I also describe my role as a Watch Officer for the National Incident Room within the OHP. I investigated a foodborne outbreak of gastroenteritis at a Mother’s Day buffet luncheon in the Australian Capital Territory (ACT), where curried prawns and Caesar salad were the suspected cause of the outbreak. The investigation was unable to determine the aetiological cause of illness but highlighted the risk often associated with serving buffet style meals. I present two epidemiological studies. The first is an analysis of notified Legionella infections from 2001 and 2012. Describing the epidemiology of legionellosis in Australia, the analysis found rates of infection are low and more likely to affect males and vulnerable populations such as the elderly. Comparing these results to a previous review of legionellosis in Australia (1991-2000), we found age, sex and season of infection were consistent, but notification rates were stable and higher compared with rates from 1991 to 2000, and Legionella longbeachae was notified more than Legionella pneumophila. I presented the findings of my analysis in an oral presentation at the 2014 Public Health Association of Australia 43rd Annual Conference in Perth. The second epidemiological project I undertook examined why Indigenous status was underreported in National Human Papillomavirus Vaccination Register (NHVPR). Analysing female vaccination records from 2007 to 2012, we identified 46% were missing Indigenous status. We reviewed the literature, examined register data and consulted with jurisdictional health departments to identify what barriers exist that potentially prevent the reporting of Indigenous status to the NHVPR. I evaluated the National Notifiable Diseases Surveillance System (NNDSS) as a surveillance system for influenza. The evaluation found that the NNDSS is an acceptable, simple and useable system that provides high quality data for the national surveillance of laboratory-confirmed influenza. However, improvements in the systems flexibility and sensitivity would ensure higher quality surveillance data continues to be available. Lastly, to fulfil my teaching requirements I prepared a ‘Lessons From the Field’ case study on how to work with Aboriginal and Torres Strait Islander data and conducted a teaching session on measurement and information biases as part of a half day training session undertaken for the MAE cohort of 2014. This thesis describes my experiences in my MAE placement, the fulfilment of requirements and the findings of my investigations. The work presented in this thesis contributes to the work of VPDS section by improving our understanding of communicable disease surveillance in Australia.