School of Public Health and Community Medicine

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NSW Hospital Infection Epidemiology and Surveillance Unit

The NSW Hospital Infection Epidemiology and Surveillance (HIES) Unit, is located in the School of Public Health and Community Medicine, at the University of New South Wales. The activities of the Unit focus on healthcare associated infections and community-based outbreaks, and includes surveillance techniques, outbreak management and behaviour of healthcare workers.

The Unit collaborates on research into patient safety, clinical epidemiology and healthcare worker behaviour that includes:

  • Patient safety
  • Pressure ulcer surveillance and prevention, multiple resistant microorganism, quality assurance programs.
  • Healthcare worker behaviour and practices related to
  • needle-stick injury, hand hygiene, standard precaution practices, patient safety activities.
  • Clinical epidemiology and surveillance methodology
  • Risk assessment of CVL, effectiveness of surgical site surveillance, post-discharge methodology.


The  HIESU provides epidemiology input to the Clinical Excellence Commission patient safety activities associated with infection prevention. These State-wide interventions aim at reducing healthcare associated infections and have included the NSW ICU central line associated bloodstream infection (CLABSI) project, the State-wide hand hygiene campaign in NSW public hospitals. Currently the Unit is collaborating with the World Health Organization (WHO) First Patient safety challenge: Clean Care is Safer Care and burden of healthcare associated infections. We are working in Cambodia exploring antibiotic prescribing practices with the aim of altering practices to reduce the risk of multiple resistant pathogens. Reduction of healthcare associated infections in Viet Nam and the impact of hand hygiene is currently being undertaken. Other research in Vietnam includes the amelioration of risk factors for blood-borne infections (including hepatitis b and C infections and HIV) associated with haemodialysis. 

Past activities

Between 1998 and 2001 a pilot surveillance project, called the Hospital Infection Standardised Surveillance (HISS), was developed and implemented on behalf of the NSW Health Department. This pilot was fully funded by NSW Health Department from and the objectives included:

  • develop and institute standardised surveillance protocol for hospitals
  • develop surveillance of healthcare associated infections focusing on patients with the highest risk of preventable infections
  • identifying sentinel surgical procedure(s) and sentinel hospital-acquired infection(s)
  • introduce hospital-based standardised analysis
  • collate aggregated data for member hospitals to establishing benchmark rates for sentinel infections.

The key components of the pilot HISS program were:

  • Voluntary membership
  • To provide an independent Unit which held no conflict of interest to receive, collate, aggregate and analyse data
  • Involvement of the stakeholders, ICPs, surgeons, intensivist, ward staff, in the hospital to collect data
  • Continuous analysis to identify unexpected trends using statistical process control charts
  • Providing assistance through periodic review of rates to identify factors associated with infection
  • Use of data to provide evidence-based policy development resulting in higher standards of patient care.

The HIES Unit collaborated to provide the latest in software and analytical techniques. The software for the SSI and IVD-RB modules, were developed in collaboration with the Division of Infection Control, Department of Infectious Diseases, Princess Alexandra Hospital, Brisbane. The statistical control chart (CUSUM and EWMA) applications were designed by Dr Tony Morton, Statistician, Department of Infectious Diseases, PAH, Brisbane and are under licence to the HISS program.

Pilot testing a standardised surveillance system identified that:

  • Infection control practitioners consistently apply standardised definitions,
  • Australia had no national rates for surgical site infection developed from aggregated rates. However, surgical site infection rates for Coronary Artery bi pass surgery, total hip replacement, colorectal and lower segment caesarean section were comparable with rates from the USA National Nosocomial Infection Surveillance (NNIS) system. Rates in the NSW pilot sites for vascular surgery and total knee replacement surgery were significantly higher than NNIS. This difference may have been in part due to the methodological difference between the pilot study and NNIS which allows individual hospital contributing to NNIS to provide small data samples (50-100 procedures) which will decrease the likelihood of identifying a reliable infection rate.
  • Central venous line-day data for CVL rates are unacceptably time consuming to collect, even when line-day data are restricted to ICU patients.
  • Analysis of the risk associated with CVL identified (i) the majority of patients have CVL in situ for up to 4 days (ii) the rate of CVL related BSI was 5.0 per 1000 (95%CI 3.0 - 7.0) (iii) the risk of CVL associated BSI increases significantly by day-13 & (iv) the risk of CVL associated BSI is greater than the risk associated with CVL insertion related pneumothorax.
  • Data collection for peripheral line associated infection rates identified the risk of a peripheral line related infection was very low (0.2 per 1000 line-days; 95%CI 0.0- 0.5) due to the removal of the lines within the recommended time frame of 48-72hours after insertion, 75% were removed within 48 hours.
  • An annual or biannual prevalence survey of peripheral lines in situ for length of time in situ to identify adherence rate to the recommended removal time for peripheral lines would be a better use of ICP surveillance time.
  • MRSA infection is epidemic regardless of bed sizes, however metropolitan hospitals had a significantly higher rate of MRSA infection, 7.3 per 10,000 acute care bed days, than principal referral hospitals, 3.3 per 10,000 acute care bed days. This difference may in part be due to different case-mix, increased age of patients with increased length of admission.