2018-09-272018-09-272018-052018-09-27May 2018http://hdl.handle.net/10388/11212Although injecting drug users (IDUs) and female sex workers (FSWs) carry a disproportionate burden of HIV in Vietnam, little is known about the dynamics of the HIV epidemic among these high-risk populations. This thesis involved a secondary data analysis of the ‘2009 HIV/STI Integrated Biological and Behavioral Surveillance’ (IBBS) study to identify the correlates of HIV among IDUs and FSWs in Vietnam. It also involved the creation and simulation of an Agent-based model (ABM) to characterize the dynamics of the HIV epidemics among IDUs and FSWs, and to explore the effects of different intervention strategies. Data collected from 3,038 male IDUs, 2,530 street-based sex workers (SSWs) and 2,768 venue-based sex workers (VSWs) from 10 provinces in Vietnam during 2009-2010 were analyzed using descriptive statistics, bivariate and multivariate logistic regression analyses. An ABM was constructed using key behavioral data from the IBBS study. Different intervention scenarios based upon different levels of behavioral change were then simulated and compared. The aggregated prevalence of HIV infection was 30.6% (n=930) among male IDUs, 10.6% (n=267) among SSWs and 6.7% (n=186) among VSWs. Lifetime needle sharing, duration of drug injection ≥ 5 years, and having regular sexual partners who injected drugs were associated with increased risk of HIV among IDUs. Independent correlates of HIV infection in multivariate analysis, regardless of sex work types, included lifetime injecting drug use, high self-perceived HIV risk, and age ≥ 25 years. Intervention scenarios of lowering needle sharing levels among those who injected drugs resulted in the largest reductions in HIV infection in all simulated populations and across various intervention scenarios of behavioral change. The majority of the reductions occurred when needle sharing levels declined from 50% to 40% and to 30%, respectively. The HIV epidemic in Vietnam requires targeted prevention interventions among populations at high-risk of HIV infection. Results from the thesis suggest drug injection-related risks play an important role in fueling the epidemic and thus underscore the need to strengthen HIV harm reduction services in Vietnam. The thesis demonstrates that the use of ABM well complements traditional epidemiologic regression-based analysis in providing important insights into the complex dynamics of the HIV epidemics among IDUs and FSWs.application/pdfHIV epidemicModelingInjecting drug usersFemale sex workersVietnamThesis2018-09-27