Factors Associated with Virological Failure under Dolutegravir-based Therapy in HIV-1 Infected Patients in the Central African Republic (2023–2025)

Abstract

Introduction: HIV‑1 remains a major public health issue, with a prevalence of 3.5% in the Central African Republic. Dolutegravir (DTG)-based regimens are recommended as first-line therapy due to their high efficacy and resistance barrier, yet virological failure persists, influenced by patient, disease, and treatment-related factors. Objective: The study aims to identify factors associated with virological failure in patients receiving DTG-based therapy in the Central African Republic (2023–2025). Methods: A retrospective cohort study with a nested case-control analysis was conducted at the National Laboratory of Clinical Biology and Public Health in Bangui, including 1,800 patients across eight treatment sites. Virological failure was defined as a viral load ≥1000 copies/mL after ≥6 months of therapy. Data were collected using standardized forms, entered into Microsoft Excel, and analyzed using SPSS version 26. Descriptive statistics were used to summarize sociodemographic, clinical, and therapeutic characteristics. Associations with virological failure were first assessed using bivariate analysis, followed by multivariate logistic regression to identify independent predictors. Odds ratios (ORs) with 95% confidence intervals (95% CI) were calculated, and statistical significance was set at p < 0.05. Results: Virological failure decreased from 15% to 8% between the first semester of 2023 and the second semester of 2025. Mean viral load declined, while CD4 counts increased from 480 to 560 cells/mm³. Independent factors associated with failure were: average/poor adherence (AOR = 6.85), opportunistic infections (AOR = 3.92), and switching to second-line therapy (AOR = 1.63). Sociodemographic factors had a secondary effect. Discussion: These findings align with African and global data, confirming that viral suppression under DTG strongly depends on adherence and clinical monitoring, while failure persists due to poor adherence, opportunistic infections, or socio-economic constraints. Conclusion: DTG-based regimens demonstrate good immunovirological efficacy in the Central African Republic. Adherence, management of opportunistic infections, and proper transition to second-line therapy are key determinants of virological failure. Recommendations: Strengthen adherence support, ensure semi-annual monitoring, improve management of opportunistic infections, train healthcare personnel, and study viral resistance and socio-economic determinants.