Syphilis and Lepto: an MAE in spirochaetes

Abstract

It was a privilege to complete my field placement for the Masters of Philosophy (Applied Epidemiology) (MAE), with the Burnet Institute between 2018 and 2022. In the midst of the global COVID-19 pandemic and a protracted part-time MAE journey, I am pleased to present here my final thesis, known colloquially as a 'bound volume' in MAE circles, which details how I have met the competencies required of a field epidemiologist for the MAE program. In chapter one, I provide an introduction to my MAE experience and outline how my projects and associated activities contribute to each of the requisite MAE competencies. In chapter two, I present an investigation into an increase in leptospirosis in the Cairns region of Far North Queensland. While heavy rainfall likely contributed to the spike in cases, my investigation was unable to confirm the presence or absence of a leptospirosis outbreak. I made recommendations to improve the identification of infecting serovars and the collection of exposure site data to support local leptospirosis surveillance and the ability to detect future outbreaks. In chapter three, I present an analysis of the trends in infectious syphilis among men who have sex with men (MSM) in Melbourne. Using sentinel surveillance data, I found that sustained efforts to increase syphilis testing among MSM in Melbourne were accompanied by increased annual syphilis test positivity and repeat infection among HIV-negative MSM, which suggested increased transmission in this population. I made a number of recommendations based on this finding and further research will be undertaken by the Burnet Institute to determine infectious syphilis incidence among HIV-negative MSM nationally. In chapter four, I present an evaluation of the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance of sexually transmitted infections and blood borne viruses (ACCESS) as Australia's sentinel surveillance system for sexually transmitted infections. ACCESS was found to be a highly useful surveillance system for monitoring the epidemiology of sexually transmitted infections in Australia and I proposed eight recommendations to the ACCESS executive committee to further strengthen the system. In chapter five I present my capstone epidemiology project, for which I developed and validated a diagnostic surveillance algorithm for infectious syphilis to demonstrate that longitudinal laboratory test results are sufficient to identify infectious syphilis cases for public health surveillance purposes. The algorithm showed acceptable diagnostic performance and will deployed in ACCESS and available for use by other similar surveillance systems. In chapter six I demonstrate my experience in teaching by presenting a data visualisation session I delivered to first year MAE students and a lesson I delivered to MAE colleagues in using some key Microsoft Excel functions for epidemiological data analysis. All of the research projects presented in this thesis contribute to the growing body of epidemiological research on infectious diseases in Australia and will help shape future public health activities and research endeavours, both locally and globally. It has been an honour to become a fully-fledged epidemiologist through the MAE program. Show more