Infectious Diseases Epidemiology

COVID response

Infectious Diseases 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 is involved in diverse areas of clinical and public health infectious disease research including:

  • assessing risk factors, frequency and impacts of infectious complications for community-acquired and nosocomial infections among various patient groups;
  • improving data on risk of infections related to contaminated environmental and water exposures in Australia and overseas, with outputs providing evidence-based science for safely expanding alternative water source use (rainwater, greywater, recycled water), for updating drinking / recycled water guidelines, and for the efficacy of preventive interventions;
  • benchmarking methodology for assessing major risk factors associated with imported infections via analysis of global sentinel surveillance data.

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 included a review of the current knowledge of Legionella species and human health risks in relation to engineered water systems (for both potable and non-potable water) and associated water-using devices and end uses.

Heads of Unit

Professor Karin Leder
MBBS (Hons), FRACP, PhD, MPH, DTMH

Professor Allen Cheng
MPH, PhD, FRACP, Grad Dip (Clin Epi), MBBS

Staff

Dr Martha Sinclair – Senior Research Fellow
Dr Robert Hall – Adjunct Senior Lecturer
Dr Joanne O'Toole – Research Fellow
Dr Fiona Barker – Research Fellow
Dr Sarah McGuinness – Research Fellow
Ms Stacey Rowe – PhD Student
Ms Pam Hayes – Research Assistant

Publications

Research

The main research interests of the Unit are:

1. Water, sanitation and health

Health issues related to contaminated environments from poorly managed sanitation are a major focus of the Infectious Disease Epidemiology Unit. Karin is leading the assessment work for a major international project, RISE (Revitalising Informal Settlements and their Environments)

This is a five-year action research program funded by a range of partners including the Wellcome Trust, MFAT and the Asian Development Bank. RISE is trialling an engineering intervention involving a water sensitive approach to water and sanitation management in 24 informal settlements across Makassar, Indonesia and Suva, Fiji. The program’s primary goals are to improve sanitation, mitigate flooding and improve dwelling and open space provision in an integrated way. RISE is designed as a randomised controlled trial, and will be assessing both environmental and human health impacts on the 12 communities which receive the intervention in the first phase compared with the 12 which receive the intervention 2 years later. Multiple benefits are anticipated, including, fewer infections, better intestinal health among children, , fewer mosquito vectors,  better psychological wellbeing, improved economic and psychological health, and reduced gender inequality through the provision of secure domestic sanitation facilities.

rise-program.org

The infectious disease epidemiology unit also has a longstanding interest in understanding potential health impacts associated with exposure to drinking water, recycled water and rainwater. 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, and it is important to perform surveillance to understand changing trends in imported diseases. The role travellers play in spreading infections globally has never been more pronounced than with the SARS-CoV-2 pandemic, with travellers playing a key role as vectors of infection. In addition, travellers can  be markers (or "sentinels") of disease - if an infected traveller returns to a country with good testing abilities and good and surveillance infrastructure after visiting a place where testing capabilities are poor, the traveller may provide a signal (sometimes the first signal) of infection in the country they visited. Both during outbreaks and at other times, travellers and immigrants face a variety of health risks, and research is 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 individualise 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

Prof Allen Cheng leads FluCAN, 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 21 hospitals nationally to provide data in real time to public health authorities. Recent studies have estimated influenza vaccine effectiveness against hospitalization with severe influenza. Visit the FluCAN website.

7. Vaccination issues and infectious disease notifications

Staff of the Unit are involved in providing advice to the World Health Organisation regarding global vaccination priorities, specifically with regards to infections such as measles. They are also using data linkages to assess factors associated with vaccine uptake and disease notifications in Victoria.

8. Antimicrobial resistance (AMR)

The Unit is involved with Monash’s Centre to Impact AMR, a newly-established collaboration to co-ordinate activities related to AMR across the University and beyond.

Some of our recent / current projects

RISE (Revitalising Informal Settlements and their Environments)

As described above, the Unit is involved in a flagship project being run through Monash University, RISE, see rise-program.org.

Review of Legionella in Water Systems

In recent decades there has been increasing concern about health risks associated with opportunistic microbial pathogens, such as Legionella bacteria, in tap water supplies. These environmental microorganisms seldom cause illness in healthy people, however severe infections may occur in those who have underlying conditions which compromise the normal defences of the body. This project involves a review of the current knowledge on Legionella species and human health risks in relation to engineered water systems (for both potable and non-potable water) and associated water-using devices and end uses. Specific scenarios of interest will be identified by consultation with water industry partners, and a qualitative risk assessment framework to evaluate health risks for each of the selected scenarios will be developed. This is a collaborative Water Research Australia project.

Management of Environmental E. coli

The bacterium E. coli has traditionally been regarded solely as an inhabitant of the gastrointestinal tract of warm-blooded animals, and has therefore been used as an indicator of recent faecal pollution in water supplies. However, it is now well established that free-living E. coli populations exist worldwide in soil and water in the absence of faecal input. These environmental E. coli strains have significant genetic differences from faecal E. coli, but most are indistinguishable by tests commonly used to assess water quality. Some environmental E. coli strains can form high density “blooms” in water storages and their presence triggers the same initial public health response as E. coli from faecal pollution events. This collaborative Water Research Australia project addressed key knowledge gaps and developed an evidence-based approach for the management of environmental E. coli blooms in Australian water supply systems.

Fact Sheet

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.

Fact Sheets on Acanthamoeba, Burkholderia, Legionella, Mycobacteria, Pseudomonas and Mosquito-borne diseases

Fact Sheet on Naegleria

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 was to investigate the effect of improving water quality via installation of RBF systems on diarrhoea incidence in rural Indian communities. Project outcomes have been reported McGuinness (2020).

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. This project involved a number of steps to develop national consensus on health targets for microbial water quality and has provided important inputs for the revision of Australian Drinking Water Guidelines .

Exposure assessment using cyanuric acid

This project demonstrated that 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. This successful pilot study showed that the methodology was practical and we now have a way to actually measure water ingestion from spray exposures instead of using “expert opinion”.

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)

Some of our past projects

Teaching

The Unit is actively involved in teaching both at the undergraduate and postgraduate levels, and coordinates the Infectious Disease Epidemiology for MPH students. Unit staff also supervise honours, doctoral, and post-doctoral students.