Applied epidemiology of infectious diseases in Australia

Abstract

My placement for the Master of Philosophy in Applied Epidemiology (MAE) degree was with the Zoonoses, Foodborne and Emerging Infectious Diseases section (ZoFE), within the Office of Health Protection, Australian Government Department of Health. This placement has allowed me to apply the skills and knowledge of the epidemiology of infectious diseases acquired throughout my degree. I focused on the following four core projects. My review of the National Enhanced Listeriosis Surveillance System (NELSS) found that it had been invaluable in listeriosis surveillance in Australia since 2010. It has been used not only to detect clusters and outbreaks but has also assisted in the identification and investigation of possible sources of these outbreaks. NELSS is viewed as valuable with a high level of acceptability by the users of the system, despite limitations including a lack of understanding of system capabilities, duplication of data entry and the system not storing all available data. This review highlights the effectiveness of enhanced surveillance for a foodborne disease, though improvements are needed. In 2013 I was part of a team that investigated an outbreak of foodborne gastroenteritis linked to a buffet meal served at a Canberra restaurant. The cohort study and environmental and laboratory investigations suggested that a breakdown in cleanliness, temperature control and food handling practices resulted in contamination of the buffet food. Our investigation resulted in public health actions, such as repairs to the kitchen of the implicated restaurant, staff training and the development of food business management plans, to limit the potential for such an outbreak to occur in the future. As there is no reliable treatment for Australian Bat lyssavirus (ABLV) or rabies virus infection upon the onset of symptoms, treatment must occur as either pre or post-exposure prophylaxis. The National Human Rabies Immunoglobulin Database records information of people who have received Human Rabies Immunoglobulin (HRIg) in Australia as part of post-exposure prophylaxis treatment. Between 1 January 2010 and 31 December 2013, 3,003 individuals received HRIg for potential exposures to ABLV or rabies virus. A third received HRIg due to potential exposures to ABLV occurring in Australia. The current messaging for the risks of ABLV infection from bats in Australia should be reviewed and revised to ensure that it is appropriately targeted and effective. Two thirds of people received HRIg for potential exposures to the rabies virus overseas. Most occurred in Indonesia and most due to exposure to monkeys. We need to continue to warn of the risk of potential exposure to rabies virus when travelling overseas, particularly to Indonesia. Q fever is a zoonosis that has a wide range of reservoirs in Australia. In humans the disease can manifest as either acute febrile illness or chronic illness that may affect the heart or liver. The Australian Government funded the National Q fever Management Program (NQFMP) from 2000 to 2006, which provided screening and vaccination for target high risk groups. We found notified Q fever cases were predominately male, aged 40 to 59 years, who resided in Queensland or New South Wales. Interestingly the age of notified Q fever cases and the proportion of cases that were female both increased over time. It may be time to re-evaluate the at-risk groups recommended for Q fever vaccination as per the Australian Immunisation Handbook. Additionally, there may be a place for an agreed and consistent enhanced dataset for collection at the jurisdictional level or at the national level to better understand the epidemiology of Q fever in Australia. Show more