HIV and Hepatitis C Among People Who Inject Drugs in Memphis, Tennessee: an Intersectional Risk Environment Analysis of the Social Determinants of Health.

Background: The Southern US is confronting bourgeoning HIV and hepatitis C virus (HCV) epidemics among people who inject drugs (PWID), yet little is known about shared and unique risk factors across the region. We applied an intersectional risk environment framework to understand infectious disease outcomes for sub-groups of PWID that experience multiple axes of social marginalization related to racial and ethnic identity and social and economic vulnerability.

Methods: HIV and HCV prevalence was estimated from the first iteration of the CDC's National HIV Behavioral Surveillance respondent driven sample of PWID in Shelby County, Tennessee in 2018. We ran adjusted multinomial models to test main and interaction effects of race/ethnicity and structural factors on the prevalence of a three-level outcome: HIV-only, HCV-only, and no infection.

Results: A total of 564 PWID participated, 558 (99%) completed HIV testing, and 540 (96%) HCV testing. Thirty (5%) were HIV-positive, 224 (40%) HCV-positive, and less than 1% were co-infected. Descriptive differences by race/ethnicity and levels of structural vulnerability for HIV and HCV subpopulations were present; however, there was no evidence for statistical interaction. In the final main effects model, HIV status was positively associated with non-Hispanic Black identity (aRR 4.95, 95% CI 1.19, 20.6), whereas HCV status was associated with non-white identity (aRR 0.11 95% CI 0.07, 0.18). Factors associated with HCV infection were higher scores of structural vulnerability (aRR 2.19 95% CI 1.10, 4.35), and criminal legal involvement (aOR 1.99 95% CI 1.18, 3.37).

Conclusion: This is the first study to implement local population-based survey data to evaluate distinctive intersections of ethnic/racial and social factors associated with HIV and HCV status among PWID in the Memphis region. Findings come at an opportune time as harm reduction programs are in development in the South and shed light to the need for socially equitable race conscious resource investment.