Applied epidemiology of communicable and non-communicable diseases, Victoria, 2016–2017

Abstract

In this thesis, I present the projects and activities I have undertaken as a Master of Philosophy in Applied Epidemiology (MAE) Scholar in Victoria between February 2016 and November 2017. I was placed with the Environmental and Genetic Epidemiology Research Group at the Murdoch Childrens Research Institute (MCRI), and the Communicable Disease Epidemiology and Surveillance Unit at the Victorian Department of Health and Human Services (DHHS). At MCRI I worked on the Barwon Infant Study, a birth cohort study designed to investigate how early life environment can influence the development of immune disorders and neurodevelopmental outcomes. At DHHS, I had the opportunity to lead an outbreak investigation, undertake an evaluation of a public health surveillance system, and an epidemiological study. Through these placements I experienced the day-to-day activities of a research institute and a state public health unit. At MCRI I conducted a data analysis on the prevalence of aero-allergen sensitisation in infancy in the Barwon region in Victoria. Sensitisation to aero-allergens in infancy is considered rare and as a result few studies report the prevalence in infants. My data fills this gap in the literature using data from a population-derived cohort study. I reported the findings of this study at the Training Programs in Epidemiology and Public Health Interventions Network Global Scientific Conference, and the Australasian Epidemiological Association Conference in 2017. My surveillance evaluation involved the first stakeholder consultation of the Influenza Complications Alert Network (FluCAN), which was established in 2009 as part of Australia’s response to the A(H1N1/09) pandemic in order to provide sentinel surveillance of influenza requiring hospitalisation. As part of the evaluation I made a number of recommendations to improve the usefulness and operation of the surveillance system many of which have already been implemented. I presented the outcomes of this evaluation to key stakeholders at the annual National Influenza Surveillance Committee in 2017. I conducted an epidemiological study on Shiga toxin-producing Escherichia coli (STEC) using 15 years of Victorian data. The primary aims of this project were to describe the epidemiology of STEC in Victoria and to investigate the length of exclusion of cases in ‘high-risk’ groups (including food handlers, child and health care workers, and children attending child care) by diagnostic method. The results of this study will inform Victoria’s policy regarding the exclusion of cases in these ‘high-risk’ groups from workplaces and child care. I also conducted an outbreak investigation, including a case-control study in order to identify the source of an outbreak of Salmonella Typhimurium at a Melbourne café. The results of the case-control study indicated that hollandaise sauce was the likely cause of the outbreak and led to public health action. The high proportion of cases hospitalised in this outbreak demonstrates the serious health implications of salmonellosis and the potential consequences of deficient storage and food handling processes for high-risk food products such as hollandaise sauce. In this thesis, I present my experience of the MAE program, and demonstrate my fulfillment of the requirements of the program and the contribution my work has made to public health in Victoria.