Infectious Disease Epidemiology Unit

Infectious Disease

Head: Professor Karin Leder MBBS(Hons) FRACP PhD MPH DTMH

Infectious Disease Epidemiology includes the study of the prevalence of infections in populations, the identification of risk factors, and the development and evaluation of effective treatment measures and prevention strategies.

The unit focuses on areas of water quality and public health, environmental impacts on infections, travellers' health, health issues in immigrants/refugees and infectious disease transmission modelling. The unit is also involved in studies on infectious diseases which represent important problems in clinical practice, including nosocomial infections and influenza.

Through its partnership with Water Research Australia Limited (WaterRA), the Infectious Disease Epidemiology Unit is a leading centre for research on public health issues relating to drinking water quality. Research projects in this area include the health impacts of microbial pathogens in drinking water, and the development of improved monitoring and risk management systems for drinking water supplies. More recently the research activities of the unit have expanded to include public health aspects of alternative water sources (including rainwater, greywater and recycled water). These lower quality water sources are being increasing used in urban areas for non-potable uses to conserve precious supplies of high quality drinking water, and as a result the potential for public exposure to these water types is increasing.

Staff

Prof Allen Cheng

Dr Martha Sinclair - Senior Research Fellow

Dr Robert Hall -  Senior Research Fellow

Dr Joanne O'Toole -  Research Fellow

Dr Fiona Barker - Research Fellow

Dr Nusrat Najnin -  PhD Student

Dr Ben Coghlan - PhD Student

Dr Sarah.McGuinness - PhD Student

Ms Pam Hayes - Research Assistant


Publications


Research

The main research interests of the Unit are:

1. Water and health:

Health issues related to drinking water, recycled water and rainwater are a major focus. Research has consisted of large randomised controlled trials, experimental work, data modelling, and questionnaires to better understand potential exposures and potential health risks associated with using different water sources. Outputs have significant implications on water guidelines and water policy in Australia.

2. Imported infections:

International travellers and immigrants play a key role in importing infections into Australia. Surveillance to understand changing trends in imported diseases is very important, as has been highlighted recently by the 2009 influenza pandemic. Travellers and immigrants face a variety of health risks, and research is also required to better understand risk factors for various infections, effective screening practices, and appropriate preventive measures that should be taken.

3. Infections in immunocompromised hosts:

There are a number of infections for which immunocompromised patients are at high risk. As an example, splenectomised patients have a significant risk of developing overwhelming and life-threatening infections from certain encapsulated bacteria. In conjunction with the Alfred hospital, staff of the ID Epidemiology Unit are involved in overseeing a state-wide "spleen registry", which captures patients undergoing splenectomies and provides them with advice to minimise their risks of infectious complications.

4. Antibiotic prescribing:

The unit collaborates with the Pharmacy Department at Alfred Health to improve antibiotic prescribing. This includes the evaluation of hospital wide interventions to influence prescriber behaviour, to the evaluation of pharmacokinetic modelling software to individualize drug dosing. Recent projects have demonstrated a reduction in broad spectrum antibiotic use following the introduction of a rapid audit and feedback system, and have demonstrated the feasibility of pharmacokinetic software to predict drug doses.

5. Healthcare associated infections:

The unit is linked to the Infection Prevention and Healthcare Epidemiology Unit at Alfred Health. Recent projects have looked at the risks of contact isolation in patients with multiresistant organisms, interventions to reduce colonisation with multiresistant organisms, and the epidemiology of healthcare infections.

6. Influenza surveillance:

The Unit was involved in setting up a national sentinel surveillance system for severe influenza in conjunction with the Alfred Hospital and the Australian National University. Currently, this system conducts sentinel surveillance at 13 hospitals nationally to provide data in real time to public health authorities. Recent studies have estimated influenza vaccine effectiveness against hospitalization with severe influenza.

7. Vaccination issues:

Staff of the Unit are involved in providing advice to the World Health Organisation regarding global vaccination priorites, specifically with regards to infections such as measles.

Some examples of recent/current projects

Emerging pathogens of concern to the water industry

This project is a review of knowledge on several environmental pathogens which may occur in water supplies. Such pathogens differ in several ways from the enteric pathogens from faecal waste that have traditionally been the focus of water quality management. In particular, environmental pathogens have the capacity to grow in water supplies and in the plumbing of buildings. They seldom cause serious infections in healthy people, and often occur in other environmental sources such as food and soil. Therefore the relative importance of water as a source of human infections is uncertain.

Improving access to safe water using Riverbank Filtration Technology

Diarrhoea is a leading cause of death and disease globally, with 90% of diarrhoea-related deaths annually being due to unsafe water, inadequate sanitation and poor hygiene. River water is a common water source, but water quality is often compromised by contamination with raw sewage and industrial effluent. In developing countries, technical water treatment solutions are unaffordable so simple, sustainable solutions are needed. Riverbank Filtration technology (RBF) uses natural, auto-regenerative treatment processes, so properly engineered RBF systems can remain effective indefinitely. RBF is inexpensive and can substantially reduce contaminant levels to improve water quality. The primary aim of this project is to investigate the effect of improving water quality via installation of RBF systems on diarrhoea incidence in six rural Indian communities. Project outcomes will have public health implications for India and other less developed countries with limited access to safe water. This is a collaborative project involving Monash University, The Energy and Resources Institute India, and the University of Rhode Island.

Establishing Australian Health Based Targets For Microbial Water Quality

It is of great public health importance to ensure that our drinking water supplies are safe. This is true both for conventional drinking water supplies and for supplies derived from alternative water sources, including water derived from recycled sewage. National guidelines exist for management of drinking water and recycled water supplies, but currently there are no targets for determining whether water has an acceptably low level of infectious agents. This project involves a number of steps to develop national consensus on health targets for microbial water quality.

Exposure assessment using cyanuric acid

This project will determine whether it is feasible to measure actual water ingestion during activities such as car washing by spiking the water with a non-toxic chemical (cyanuric acid) and measuring the amount of the chemical subsequently excreted in urine. Cyanuric acid is widely used in outdoor swimming pools to "stabilise" chlorine by protecting it from UV degradation. When ingested, this compound is not metabolised but is 100% excreted in the urine within 24 hours. Measurement of cyanuric acid in urine has been successfully used to estimate water ingestion during swimming.
Report to Participants (PDF)

Greywater use in the backyard: what are the health risks?

This project involved administering a survey to Melbourne householders asking them about their greywater use and monitoring greywater quality at selected households. Results have fed into a mathematical model to predict greywater related infection risk and disease burden. Report to Participants (PDF)

List of some past projects

*Health services utilisation and urban dual reticulation systems
*Exposure assessment for urban reticulation systems
*A series of exposure experiments: recycled water and alternative water sources
*Health effects of rainwater consumption
*Developing evidence-based strategic water quality monitoring systems
*The Water Quality Study* Economic evaluation of community gastroenteritis *Norwalk-like viruses and drinking water
*Disinfection byproduct exposure assessment
*Case-control studies of cryptosporidiosis (Melbourne and Adelaide)
*A system for the early detection of outbreaks of water-related gastroenteritis
*The effect of chlorination on the rates of gastroenteritis
*Fluoridation of drinking water supplies


Teaching

The Unit is actively involved in teaching both at the undergraduate and postgraduate levels, and coordinates the Masters of Clinical Research Methods program and a course entitled "Infectious Disease Epidemiology" for MPH students. Unit staff also supervise honours, doctoral, and post-doctoral students.