Background:
Advances in HIV and hepatitis C virus (HCV) prevention and treatment have led to plans to end the HIV epidemic and achieve HCV elimination by 2030. Data on long-term trends in the uptake of combination HIV/HCV prevention services and their impact on HIV/HCV incidence among people who inject drugs (PWID) are limited.
Methods:
The AIDS Linked to the IntraVenous Experience (ALIVE) study is a community-based cohort of PWID aged ≥18 years in Baltimore, Maryland with 5 enrollment periods: 1988-89, 1994-95, 1998, 2005-08, and 2015-18. We assessed trends in HIV and HCV seroincidence, prevalence of injection practices, self-reported use of prevention and treatment services, HIV viremia (>400 c/mL) and HCV viremia (>500 IU/mL) using Poisson and logistic regression with generalized estimating equations. Data were censored at 12/31/2019 (prior to the COVID-19 pandemic).
Results:
Overall, 5,506 participants attended 68,107 semi-annual visits. At enrollment, median age was 37 years; 26% were female. Of 2,657 initially HIV-seronegative participants, 282 seroconversions occurred over 18,452 person-years (py). Of 593 initially HCV-seronegative participants, 115 seroconversions occurred over 3,576 py. HIV incidence declined from 4.1/100py in 1988-1992-a period without combination prevention services-to 0.5/100py in 1999-2001 (IRR=0.12 [95%CI=0.06-0.23]) and continued to decline to 0.1/100py in 2017-2019 (IRR=0.02 [0.00-0.13]) (Figure). Although HCV seroincidence similarly declined from 9.8/100py in 1988-1992 to 1.7/100py in 1999-2001 (IRR=0.18 [0.08-0.39]), it generally remained high thereafter (e.g., 4.0/100 py in 2017-2019). Early declines in HIV and HCV incidence were associated with declines in injection drug use (89% in 1988; 51% in 2001; 36% in 2019) and increases in prescribed methadone use (10% in 1988; 22% in 2001; 44% in 2019) and syringe services program use (36% in 1998; 44% in 2001; to 51% in 2019). Later declines in HIV incidence were also associated with increases in ART use (55% in 2006; 96% in 2019) and declines in HIV viremia (63% in 2007; 36% in 2019). However, HCV seroincidence remained high during periods in which HCV treatment uptake increased (2% in 2014; 56% in 2019) and HCV viremia declined (84% in 2006; 36% in 2019).
Conclusions:
In a cohort of PWID, HIV and HCV seroincidence decreased over time corresponding with increased prevention efforts and behavioral changes; however, HCV seroincidence remained high. Intensified efforts are needed to achieve HCV elimination among PWID.
