Applied Epidemiology in the Hunter New England and Western Pacific regions

Abstract

In this thesis, I present work conducted as a Master of Philosophy (Applied Epidemiology) (MAE) Scholar based at the OzFoodNet sentinel site at Hunter New England Population Health. During my placement, I was involved in a number of public health investigations both locally and in the Western Pacific region. The MAE core competency requirements and the epidemiological skills that I developed through my field placement are demonstrated in the following chapters.

I was fortunate to be at the coalface of public health in my placement at the Local Health District and was able to be involved in a number of outbreak investigations. I led an investigation of an outbreak of Campylobacter in a rural community in New South Wales. This investigation included a retrospective cohort study with the aim of characterising cases and identifying the source of infection to prevent further illness. Data were collected on food and animal exposures prior to the first onset of illness in the community. We found no statistically significant food exposures, however this was complicated by near universal exposure to some food items. A review of cooking processes identified undercooked chicken as the likely source of infection in this outbreak. I was also involved in local outbreaks of gastroenteritis associated with a primary school and a Salmonella Typhimurium outbreak associated with a restaurant. In addition, I was involved in an investigation of paediatric severe acute respiratory infections requiring admission to intensive care units as a part of a World Health Organization deployment to Fiji in May 2016.

I conducted an epidemiological project examining environmental risk factors for human infection with Salmonella serovar Wangata in north east New South Wales. I designed and administered a case-control study in three Local Health Districts. Data on environmental exposures were collected for cases and two separate control groups: cases of Salmonella Typhimurium and community controls from the neighbourhood of cases. This project included a large data analysis component, with separate multivariable logistic regression models developed to analyse environmental exposures in each control group. Whole genome sequencing was used to examine the relatedness between human isolates and environmental specimens collected as a part of this project.

During my deployment to Fiji in May 2016, I was involved in the surveillance of infectious diseases following Tropical Cyclone Winston. I co-evaluated the Early Warning Alert and Response System (EWARS in a Box) with fellow MAE Scholar, Meru Sheel. Nine syndromes were reported to the EWARS system from 34 sentinel sites in Fiji. The web based EWARS system utilised smartphone reporting and was considered simple, acceptable and generally useful for users. Recommendations were made to improve the layout and interpretation of surveillance reports and to enhance operating procedures and guidelines for surveillance officers. This was the first time the EWARS in a Box system had been implemented in a Pacific Island Country and the experiences of the system in Fiji can be used to assist other countries in the region who are experiencing humanitarian disasters.