Applied Epidemiology in New South Wales: Viruses, Vectors and Vomitus

Abstract

Abstract

Hunter New England Population Health is responsible for the delivery of population health services to the Hunter New England Local Health District (HNELHD) region of New South Wales (NSW). From February 2022 to October 2023 I undertook my MAE field placement in the Health Protection team. From March 2022 to January 2023 I was also able to support the work conducted by the One Health Branch at Health Protection NSW. This thesis presents the projects undertaken during my field placement as well as work with the One Health Branch.

This thesis describes four significant public health problems. The four major projects are: 1) A serological survey of Japanese encephalitis virus (JEV) infection in high-risk townships, NSW, Australia, 2022. This serosurvey was conducted to determine the proportion of people infected with JEV in high risk towns in NSW and to identify possible risk factors for infection. The study was the first community-based JEV serosurvey completed in south eastern Australia and demonstrated 1 in 11 people in high risk areas of NSW were infected with JEV after a single arbovirus season. The results informed public health response activities including vaccination, mosquito bite prevention campaigns and public health communications. 2) An investigation into an outbreak of Salmonella Typhimurium (STm) associated with a conference held at a venue in Terrigal, NSW. Following the identification of an outbreak on 1 December 2022, a state-wide outbreak response was initiated. A retrospective cohort study was conducted of all conference attendees, event and venue staff who had consumed food at the venue. This chapter describes the epidemiological, microbiological and environmental investigation and results. It also describes the control measures and the implications of the outbreak for food safety. 3) A cross-correlation analysis of influenza laboratory data and self-reported influenza-like illness in NSW, 2010 to 2019. This analysis was conducted to compare the performance of the FluTracking influenza-like illness timeseries to influenza laboratory percent positivity data and notified influenza case data. This analysis demonstrated that self-reported fever and cough were strongly correlated with both percent positivity and notifications data in years where the influenza season followed a typical epidemiological pattern. Results from this analysis contribute to the validation of FluTracking as an influenza surveillance system. 4) A surveillance evaluation of the utility of FluTracking during the COVID-19 pandemic, 2020-2022. This study was conducted as a mixed methods sequential exploratory design and included data from 18 stakeholders. This chapter describes the FluTracking system, it's usefulness as a participatory surveillance system adapted for COVID-19, and the main contributions of FluTracking for COVID-19 disease surveillance. Findings include the strengths and limitations of participatory COVID-19 surveillance, and recommendations for improvement of FluTracking.

This thesis also describes other public health activities undertaken during this time, including: representation of the MAE program at TEPHINET International Nights in Atlanta, Georgia, USA; contribution to the NSW Japanese Encephalitis virus outbreak response; contribution to the NSW Cryptosporidiosis control guideline review; development of a questionnaire for hepatitis of unknown aetiology; conducting data analysis and writing for the 2021 NSW OzFoodNet annual report; teaching other MAE scholars; and tutoring in to the Master of Public Health program with the Wollotuka Institute at the University of Newcastle. These projects and experiences fulfil the core requirements of the Australian National University Master of Philosophy (Applied Epidemiology) program. Show more