Modelling the hepatitis C virus epidemic in Australia

Razali, Karina; Thein, Hla Hla; Bell, Jane; Cooper-Stanbury, Mark; Dolan, Kate; Dore, Greg; George, Jacob; Kaldor, John; Karvelas, Maria; Li, Jiong; Maher, Lisa; McGregor, Sharyn; Hellard, Margaret; Poeder, Fiona; Quaine, Julianne; Stewart, Kim; Tyrrell, Helen; Weltman, Martin; Westcott, Owen; Wodak, Alex; Law, Matthew

doi:10.1016/j.drugalcdep.2007.05.026

« Previous Next »Drug and Alcohol Dependence
Volume 91, Issue 2 , Pages 228-235, 1 December 2007

Modelling the hepatitis C virus epidemic in Australia

Karina Razali
- National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, NSW 2010, Australia
- Corresponding author. Tel.: +61 2 93825 0900; fax: +61 2 9385 0920.
Hla Hla Thein
- National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, NSW 2010, Australia
Jane Bell
- Department of Health and Ageing, Canberra, ACT 2601, Australia
Mark Cooper-Stanbury
- Australian Institute of Health and Welfare, Canberra, ACT 2617, Australia
Kate Dolan
- National Drug and Alcohol Research Centre, University of New South Wales, Sydney, NSW 2052, Australia
Greg Dore
- National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, NSW 2010, Australia
Jacob George
- Westmead Millenium Institute, Westmead, NSW 2145, Australia
John Kaldor
- National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, NSW 2010, Australia
Maria Karvelas
- Victorian Government Department of Human Services, Melbourne, VIC 3000, Australia
Jiong Li
- National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, NSW 2010, Australia
Lisa Maher
- National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, NSW 2010, Australia
Sharyn McGregor
- Department of Health and Ageing, Canberra, ACT 2601, Australia
Margaret Hellard
- Burnet Institute, Melbourne, VIC 3001, Australia
Fiona Poeder
- Australian Injecting and Illicit Drug Users League Inc., Canberra, ACT 2600, Australia
Julianne Quaine
- Department of Health and Ageing, Canberra, ACT 2601, Australia
Kim Stewart
- NSW Health, North Sydney, NSW 2060, Australia
Helen Tyrrell
- Australian Hepatitis Council, Woden, ACT 2606, Australia
Martin Weltman
- Nepean Hospital, University of Sydney, Sydney, NSW 2006, Australia
Owen Westcott
- NSW Health, North Sydney, NSW 2060, Australia
Alex Wodak
- Alcohol and Drug Service, St Vincent's Hospital, Sydney, NSW 2010, Australia
Matthew Law
- National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, Sydney, NSW 2010, Australia

Received 13 December 2006; received in revised form 30 May 2007; accepted 30 May 2007.

Abstract

Background

Hepatitis C virus (HCV) infection in Australia is predominantly transmitted through injecting drug use. A reduction in the heroin supply in Australia in late 2000 and early 2001 may have impacted the number of injecting drug users (IDUs) and consequently the number of new hepatitis C infections in Australia. This paper updates estimates of HCV incidence and prevalence between 1960 and 2005.

Methods

Simple mathematical models were used to estimate HCV incidence among IDUs, migrants to Australia from high HCV-prevalence countries, and other HCV exposure groups. Recent trends in numbers of IDUs were based on indicators of injecting drug use. A natural history of HCV model was applied to estimate the prevalence of HCV in the population.

Results

The modelled best estimate of past HCV incidence showed a consistent increasing rate of HCV infections to a peak of 14,000 new seroconversions in 1999, followed by a decline in 2001–2002 coincident with the decline in heroin availability. HCV incidence was estimated to be 9700 (lower and upper limits of 6600 and 13,200) in 2005. Of these, 88.7% were estimated to be through injecting drug use, 7.2% among migrants and 4.1% through other transmission routes. An estimated 264,000 (lower and upper limits of 206,000 and 318,000) people were HCV antibody positive in 2005.

Conclusions

Mathematical models suggest that HCV incidence in Australia decreased from a peak of 14,000 new infections in 1999 to 9700 new infections in 2005, largely attributable to a reduction in injecting drug use. The numbers of people living with HCV in Australia is, however, estimated to continue to increase.

Keywords: Hepatitis C virus, Australia, Mathematical models, Epidemic, Injecting drug use