Suchergebnisse

Mathematical models are useful tools for understanding complex dynamical systems, such as infectious disease epidemics. This thesis aims to apply techniques of mathematical modelling to the studies of HIV and hepatitis C epidemiology in Australia and Indonesia 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 to reflect incidence among PWID in Australia. This static mathematical model is developed to estimate how changes in sterile syringe distribution through NSPs may affect HIV and HCV incidences among PWID in Australia. Chapter 3 presents costeffectiveness and 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 evaluate past and project intervention impact is described in Chapter 4. The interface was applied to various risk and geographical populations in Indonesia in order to match HIV prevalence data, and coverage of antiretroviral therapy (ART). Trends in the expected 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 estimate an economically optimal ART expansion strategy for reducing HIV infections among high-risk populations in Indonesia. The impact 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 Indonesian government. Chapter 5 is yet to be published but is in the process of submission to an international journal.

AbstractIntroductionSimplified hepatitis C virus (HCV) diagnostic strategies have the potential to improve HCV diagnoses and treatment. We aimed to investigate the impact of simplified HCV diagnostic strategies on HCV incidence and its effect on HCV diagnosis and treatment among men who have sex with men (MSM) regardless of HIV status and use of HIV pre‐exposure prophylaxis (PrEP) in Taiwan.MethodsA compartmental deterministic model was developed to describe the natural history of HCV disease progression, the HCV care cascade and the HIV status and PrEP using among MSM. The model was calibrated to available data for HCV and HIV epidemiology and population demographics in Taiwan. We simulated the epidemic from 2004 and projected the impact of simplified testing strategies on the HCV epidemic among MSM over 2022–2030.ResultsUnder the current testing approach in Taiwan, total HCV incidence would increase to 12.6 per 1000 person‐years among MSM by 2030. Single‐visit point‐of‐care RNA testing had the largest impact on reducing the number of new HCV infections over 2022–2030, with a 31.1% reduction (interquartile range: 24.9%−32.8%). By 2030, single‐visit point‐of‐care HCV testing improved HCV diagnosis to 90.9%, HCV treatment to 87.7% and HCV cure to 81.5% among MSM living with HCV. Compared to status quo, prioritized simplified HCV testing for PrEP users and MSM living with diagnosed HIV had considerable impact on the broader HCV epidemic among MSM. A sensitivity analysis suggests that reinfection risk would have a large impact on the effectiveness of each point‐of‐care testing scenario.ConclusionsSimplified HCV diagnostic strategies could control the ongoing HCV epidemic and improve HCV testing and treatment among Taiwanese MSM. Single‐visit point‐of‐care RNA testing would result in large reductions in HCV incidence and prevalence among MSM. Efficient risk‐reduction strategies will need to be implemented alongside point‐of‐care testing to achieve HCV elimination among MSM in Taiwan.