The epidemiological transmission model for HIV and HCV was applied to IDUs and NSPs specifically in the Australian Capital Territory. The model was used to evaluate current NSPs versus no program and to project likely epidemiological impAustralian Capital Territorys of potential changes to the program. The model estimated the expected number of HIV and HCV cases in the Australian Capital Territory with and without NSP distribution of sterile injecting equipment (Figure 25). The estimated cumulative number of infections averted is presented in Figure 26. Less than one HIV infection would be expected due to syringe sharing by IDUs, on average, in the Australian Capital Territory even without NSPs. Thus, NSPs are currently not preventing HIV infections in the Australian Capital Territory. However, NSPs are very effective in averting HCV transmissions. It is estimated that over the last ten years they have averted 1,482 (1,451-1,534, IQR) new HCV infections.

Figure 25: Estimated HIV and HCV incidence in the Australian Capital Territory with and without NSPs

Text equivalent below for Figure 25: Estimated HIV incidence in the Australian Capital Territory with NSPsText equivalent below for Figure 25: Estimated HIV incidence in the Australian Capital Territory without NSPsText equivalent below for Figure 25: Estimated HCV incidence in the Australian Capital Territory with NSPsText equivalent below for Figure 25: Estimated HCV incidence in the Australian Capital Territory without NSPs

Text version of Figure 25

Top of pageFigures in this description are approximate as they have been read from the graph.

Figure 25 consists of four graphs:
    • Expected annual HIV incidence in the Australian Capital Territory with NSPs

      • The 100 model simulations remain static, well below 0.01 for all years between 1999 and 2009.

      • The median of the model simulations remains static, well below 0.01 for all years between 1999 and 2009.

      • The lower quartile of the model simulations remains static, well below 0.01 for all years between 1999 and 2009.

      • The upper quartile of the model simulations remains static, well below 0.01 for all years between 1999 and 2009.

      • The notification data for annual incidence of HIV in the Australian Capital Territory remains consistently below 0.01 for all years between 1999 and 2007.

    • Expected annual HIV incidence in the Australian Capital Territory without NSPs

      • The 100 model simulations rise from 0 in 1999 to a range of 0.03-0.18 in 2004. By 2006, simulations range from 0.03 to above 0.5.

      • The median of the model simulations rises from almost 0 in 1999 to 1.9 in 2009.

      • The lower quartile of the model simulations rises from almost 0 in 1999 to 0.1 in 2009.

      • The upper quartile of the model simulations rises from almost 0 in 1999 to 0.3 in 2009.

      • The notification data for annual incidence of HIV among Australian IDUs is consistently below 0.1 for all years between 1999 and 2007.

    • Projected annual HCV incidence in the Australian Capital Territory with NSPs

      • The 100 model simulations decrease gradually from a range of 160-200 in 1999 to a range of 90-110 in 2003 and remains consistent to 2009.

      • The median of the model simulations decreases gradually from 180 in 1999 to 100 in 2003 and remains consistent to 2009.

      • The lower quartile of the model simulations decreases gradually from 170 in 1999 to 90 in 2003 and remains consistent to 2009.

      • The upper quartile of the model simulations decreases gradually from 200 in 1999 to 110 in 2003 and remains consistent to 2009.

      • The notification data for annual incidence of HCV in the Australian Capital Territory is consistently below 200 for all years between 1999 and 2005. Top of page

    • Projected annual HCV incidence in the Australian Capital Territory without NSPs

      • The 100 model simulations increase sharply from a range of 280-480 in 1998 to 800-1180 in 1999 and decrease sharply to 180-320 in 2001. The model simulations decrease further to 0-80 in 2003 before increasing to 200-380 by 2006 and increase very gradually to 210-390 by 2009.

      • The median of the model simulations increases sharply from 390 in 1998 to 1050 in 1999 and decreases sharply to 200 in 2001. The median decreases further to 50 in 2003 before increasing to 290 by 2006 and increases very gradually to 300 by 2009.

      • The lower quartile of the model simulations increases sharply from 390 in 1998 to 1000 in 1999 and decreases sharply to 190 in 2001. The lower quartile decreases further to 20 in 2003 before increasing to 270 by 2006 and increases very gradually to 280 by 2009.

      • The upper quartile of the model simulations increases sharply from 390 in 1998 to 1100 in 1999 and decreases sharply to 210 in 2001. The upper quartile decreases further to 60 in 2003 before increasing to 310 by 2006 and increases gradually to 350 by 2009.

      • The notification data for annual incidence of HCV in the Australian Capital Territory is consistently below 200 for all years between 1999 and 2005.

Figure 26: Estimated cumulative number of HIV and HCV cases averted in the Australian Capital Territory due to NSPs

Text equivalent below for Figure 26: Estimated cumulative number of HIV cases averted in the Australian Capital Territory due to NSPsText equivalent below for Figure 26: Estimated cumulative number of HCV cases averted in the Australian Capital Territory due to NSPs

Text version of Figure 26

Figures in this description are approximate as they have been read from the graph.Top of page

Figure 26 consists of two graphs:
    • Expected cumulative number of HIV cases averted in the Australian Capital Territory due to NSPs

      • With NSPs (current coverage) the cumulative number of HIV cases remains consistently below 0.01 for all years between 1999 and 2009.

      • Without NSPs the cumulative number of HIV cases increases exponentially from below 0.01 in 1999 to 0.7 in 2009.

    • Expected cumulative number of HCV cases averted in the Australian Capital Territory due to NSPs

      • With NSPs (current coverage) the cumulative number of HCV cases increases gradually from below 100 in 1999 to 2000 in 2009.

      • Without NSPs the cumulative number of HCV cases increases sharply from 100 in 1999 to 1900 in 2001, where it remains until 2003, where it begins to increase gradually, reaching 3,500 by 2009.