Socio-ecological Determinants of Detectable Viremia among Pregnant People Living with HIV in South Brazil: The Role of Stimulant Use Disorder and Homelessness.

Pregnant patients living with HIV are a priority group for the recruitment into the HIV healthcare cascade to prevent adverse maternal and neonatal health outcomes. Understanding the structural, interpersonal, and individual factors that are associated with detectable HIV viremia is of importance to guide outreach and intervention priorities. This was a retrospective cohort study of pregnant patients living with HIV who delivered from January 1, 2017, to December 31, 2023, at a tertiary-level hospital and referral institution for HIV care in Porto Alegre, Brazil. The socio-ecological model was used to guide hypothesis testing regarding associations with detectable viremia. In total, 549 patients were included, of whom 110 (20%) were found to have detectable viremia. Significant differences between detectable and undetectable viremia included prenatal care, homelessness, having a sero-different partner, and stimulant use. Multivariable associations included prenatal care (adjusted Risk Ratio [aRR] = 0.20, 95% Confidence Interval [95% CI] = 0.15-0.26), homelessness (aRR = 4.02, 95% CI = 2.74-0.26), stimulant use disorder (aRR = 3.30, 95% CI = 2.23-4.87), crack use (aRR = 2.82, 95% CI = 1.85-4.29), and cocaine use (aRR = 1.89, 95% CI = 1.17-3.06). Intervention research should focus on housing and mental health services, and how to mitigate their impact on HIV healthcare. Intervention research is greatly needed as current tools may not be sufficient to tackle the issue of stimulant use disorder and its effects on ART adherence.