Evaluating and informing programs fro the control of HIV and hepatitis C infection among female sex workers in Viet Nam

In the early 2000s, HIV surveillance in Viet Nam indicated that female sex workers (FSW) were among key populations with highest HIV infection rates. However, data on risk factors for HIV infection to inform prevention programs were limited. Data on HCV prevalence among FSW were scarce but suggested elevated burden in some regions of the country. Between 2004 and 2010, efforts were intensified nationwide to control HIV infection among FSW, and a series of cross-section surveys were conducted; in 2015 a national response was initiated to address high hepatitis C virus (HCV) burden. This thesis aimed to evaluate and inform HIV and HCV prevention among FSW in Viet Nam using empirical data from surveys and integrated analysis with program data. In Chapters 3 and 4, we report high HIV and HCV prevalence and up to 14% active HIV and HCV co-infection in urban settings. Strong associations between injection and non-injection drug use with both infections support the need for a comprehensive HIV and HCV prevention package addressing substance use risks among FSW. Inconsistent condom use was identified as an additional risk factor for HIV in provinces with HIV prevalence ≥10%, but not in provinces with <10% prevalence among street- and venue-based FSW, where only injection drug use was a significant behavioral risk factor. In Chapter 6, we synthesized four surveys conducted across 13 years and programmatic data collected over 23 years in Ho Chi Minh City, where HIV burden is highest. The scale and intensity of program coverage was low by global standards, even during peak funding and intervention coverage, and there was a clear lack of attention to substance use risks. Condom use and HIV testing uptake levels remained low across all years. Only knowledge about HIV transmission risks and perceived risk of infection reflected the scale of these interventions. The key behavioral determinants of consistent condom use were related to substance use, specifically daily alcohol intak