Modelling HIV and hepatitis C among injecting drug users in Australia and HIV among risk groups in Indonesia: projection and cost-effectiveness analysis

Mathematical models are useful tools for understanding complex dynamical systems, such as infectious disease epidemics. Thisthesis aims to apply techniques of mathematical modelling to the studies of HIV and hepatitis C epidemiology in Australia andIndonesia particularly focused on viral transmission with intravenous drug use. This thesis is divided into five chapters.Chapter 2 formulates a predictive relationship between NSPs and the risk of HIV/HCV transmission among PWID, calibrated toreflect incidence among PWID in Australia. This static mathematical model is developed to estimate how changes in sterilesyringe distribution through NSPs may affect HIV and HCV incidences among PWID in Australia. Chapter 3 presents costeffectivenessand return on investment analyses of NSPs with respect to HIV/HCV infections among Australian PWID.A graphical user interface around a new mathematical model developed to estimate HIV transmission in Indonesia and evaluatepast and project intervention impact is described in Chapter 4. The interface was applied to various risk and geographicalpopulations in Indonesia in order to match HIV prevalence data, and coverage of antiretroviral therapy (ART). Trends in theexpected HIV incidence both overall and in each population group are calculated.Chapter 5 presents a cost-effectiveness analysis of ART expansion in Indonesia. In this chapter, the analysis is used to estimatean economically optimal ART expansion strategy for reducing HIV infections among high-risk populations in Indonesia. Theimpact of increasing ART coverage and expansion of treatment-eligible criteria are assessed.Chapters 2 and 3 of this thesis are published in international journals. Chapter 4 is published as a report to the Indonesiangovernment. Chapter 5 is yet to be published but is in the process of submission to an international journal