UC San Diego

Background: Incarceration is associated with increased risk of hepatitis C virus (HCV) among people who inject drugs (PWID). If properly implemented, public health oriented drug law reforms can reduce adverse health outcomes among PWID. This dissertation investigates (1) the cumulative effect of repeated incarceration on injecting risks among PWID in Tijuana; (2) the potential impact of implementing Mexico’s drug law reform on the HCV epidemic among PWID in Tijuana; and (3) the impact of a police education program on the burden of HCV among PWID in Tijuana. Methods: Chapter 2 examines the longitudinal association between cumulative incarceration with receptive syringe sharing using cohort data among PWID in Tijuana. Chapter 3 presents a mathematical model of incarceration and HCV transmission among PWID to estimate the 10-year population attributable fraction of incarceration to HCV incidence among PWID, and the impact of implementing drug law reform on HCV incidence among PWID in Tijuana. Chapter 4 estimates the impact of a real-life police education program on HCV disease burden among PWID in Tijuana, using epidemic modeling. Results: Chapter 2 showed every additional incarceration episode increased the odds of syringe sharing by 17% (95% confidence interval [CI] 1.05-1.29). The increased odds of receptive syringe sharing persisted up to 1.5 years post-incarceration. Chapter 3 projected that incarceration is associated with 5.4% (95% uncertainty interval [UI] 0.6-11.9%) of new HCV infections among PWID in Tijuana between 2022–2032. Also, fully implemented drug law reforms (decriminalization and OAT diversion) could reduce HCV incidence rate by 10.6% (UI: 3.1-19.2%) across 10 years. Chapter 4 showed that, over the 2-year implementation, Escudo reduced HCV incidence from 21.1 per 100 person years (/100py) (UI 17–27/100py) in 2016 to 20.7/100py (UI:16-26/100py) in 2018, averting 13 (UI: 3-26) infections from 2016-2018. Using a 50-year time horizon, a 2-year reduction in incarceration from Escudo could avert a total of 120 (UI: 19-260) cases of cirrhosis. Conclusions: These findings broaden the knowledge of the deleterious effects of incarceration on the health of PWID and inform evidence-based policymaking and interventions at the intersection of drug law reform, policing, and injection drug use.