Retention in care of people on antiretroviral therapy who inject drugs in South Africa.

Background: Retention of people who inject drugs (PWID) on antiretroviral therapy (ART) is critical for viral suppression. However, PWID, a key population, traditionally have poor retention in care (RiC). Objectives: To determine the prevalence of and factors associated with RiC at 6 months, following ART initiation in three South African districts. Method: Data of 333 PWID (adults 18+ years), who commenced ART between July 2022 and March 2023, were retrieved from TIER.Net electronic database. Results: RiC after 6 months on ART was 40% (n = 132). Bivariate analysis showed higher retention among those on Opioid Substitution Therapy (OST) with treatment support compared to those without support (95% vs 39%; P < 0.001); and lower RiC among those with unstable housing compared to those with stable housing (12% vs 75%; P < 0.001). In the survival analysis, PWID with unstable housing had a 5-fold increased risk of poor RiC (adjusted hazard ratio [AHR] = 4.94; 95% confidence interval [95% CI]: 2.35-10.35), while those in OST had a 75% decreased risk of poor RiC (AHR = 0.25; 95% CI: 0.10-0.60). Conclusion: PWID face significant challenges in remaining engaged in ART care, particularly those experiencing unstable housing. OST uptake can facilitate improved RiC and health outcomes, highlighting the need for expanded harm reduction strategies. Addressing unstable housing remains urgent to strengthen HIV treatment outcomes for PWID in South Africa.