Prevention and Control of Communicable Diseases in Australia

As modern transport and technology bring the world's growing animal and human populations closer together, the public health challenges associated with the spread of infectious diseases are expanding. However, in parallel, advances in laboratory technology, communication and management have led to new ways to identify, manage and combat these threats. This thesis presents five projects to fulfil the core competencies required for the Master of Philosophy in Applied Epidemiology. The projects demonstrate the diverse range of epidemiological skills needed to respond to the challenge of infectious diseases in the 21st century. While placed at the National Centre for Immunisation Research and Surveillance (NCIRS), I completed two projects related to the prevention of disease through immunisation. Additional placements were completed at Communicable Diseases Branch, at New South Wales (NSW) Health and in West Africa as part of the World Health Organization (WHO) Ebola support team. I completed an analysis of rubella and congenital rubella syndrome (CRS) notifications and hospitalisations in Australia from 2008-2012. The report highlights the success of the Australian immunisation program in preventing cases of CRS in Australia and draws attention to the high proportion of rubella and CRS attributable to importation from endemic countries. The ease with which diseases can cross borders was further highlighted through the course of the Ebola virus disease (EVD) epidemic in west Africa, 2014-2015. In response to the threat posed to Australia by the EVD epidemic, I was invited to oversee the establishment and evaluation of a program of screening and monitoring arrivals from EVD affected countries in NSW. The evaluation described the appropriate management of arrivals who developed symptoms and provided recommendations to improve the efficiency of the program. Six months later, I was deployed as an epidemiologist in Sierra Leone. In this role, I supported the implementation of public health responses to EVD, including case investigation and contact tracing. Closer to home, I investigated an outbreak of atypical pneumonia among five staff and students of a veterinary school in rural NSW. The use of culture independent testing technology, i.e., real-time polymerase chain reaction testing, provided crucial laboratory evidence to support epidemiological findings implicating equine fetal membranes as the source of the outbreak. To our knowledge this was the first report of Chlamydia psittaci transmission from a horse to humans. As a result of the investigation, recommendations regarding the use of personal protective equipment for the examination of abnormal equine fetal membranes have been disseminated to veterinarians state-wide. Lastly, I evaluated the effectiveness of text messaging and calendar reminders to improve the timeliness of childhood vaccinations. Initial results showed that among the group that received both text message and calendar reminders, children were 26% more likely to have received their vaccinations on time compared to the control group (p-value=0.156). These results demonstrate the potential of new technologies to address the problem of under-immunisation in Australia. The work presented in this thesis contributes to knowledge and practice in communicable disease control both in Australia and overseas