Applied Epidemiology of Infectious Diseases in Western Australia

Abstract

Western Australia (WA), covering 2,529,875 km2, or 1/3 of Australia, is the largest jurisdiction in Australia and the second-largest country division in the world. The capital city, Perth, boasts the largest city park in the world, Kings Park and is home to 2 million people. It is in this wonderful city that I was placed for my Masters of Philosophy in Applied Epidemiology (MAE). Through my placement in the Bacteriology Research & Development (R&D) Laboratory at PathWest Laboratory Medicine and at the Communicable Disease Control Directorate (CDCD) of WA Health I undertook the research presented in this thesis. Following on from previous work, I performed a cross-sectional survey of gastrointestinal carriage of and environmental contamination with Clostridium difficile in aged care facilities. I performed all the laboratory work in the Bacteriology R&D Lab. This research was performed with a prominent not-for-profit care organisation, located in the northern suburbs of metropolitan Perth. This chapter also includes a focused literature review regarding C. difficile in the elderly. In November 2014, I presented these findings at the Australian College of Infection Prevention and Control Conference in Adelaide. Through my placement at the CDCD, I worked with the Healthcare Associated Infection Unit (HAIU) to evaluate the Healthcare Infection Surveillance WA (HISWA) system in accordance with the CDC guidelines for evaluating a public health surveillance system. HISWA is a web-based, state-wide surveillance system that collects data on healthcare-associated infections from healthcare facilities across WA. Whilst working with the HAIU, I assisted in investigating an outbreak of community-associated MRSA in abattoir workers in a regional town. For this project I worked with the co-investigators in writing an article for publication. I also worked with the WA branch of OzFoodNet in investigating an outbreak of norovirus at a hotel restaurant in rural WA. For my data analysis project, I analysed mosquito trap site and enhanced case surveillance data for Ross River virus in the south-west region of WA from 2002 – 2013, using negative binomial regression and mapping software. This project was undertaken with assistance from the Mosquito-borne Disease Control group of WA Health, the Arbovirus Research and Surveillance Laboratory of UWA. I participated in a Communicable Disease Network Australia (CDNA) working group for investigating the pseudo-outbreak of Barmah Forest virus across Australia. For this project I wrote a report for the CDNA regarding the activities of the working group and analysed national notification data from 2000 – 2013. For the teaching exercises, I was involved in teaching a session on critical appraisal of scientific literature. For my Lessons from the Field I shared on sample size and power calculations. Overall the work in this thesis contributes to a broader understanding of infectious disease epidemiology and surveillance in Western Australia, particularly in regards to healthcare associated infections, gastrointestinal infections and arbovirus disease.