Long-term virological outcomes, failure and acquired resistance in a large cohort of Ugandan children

Abstract

Abstract Objectives To evaluate long-term virological failure (VF) and drug resistance among HIV-infected Ugandan children on first-line ART. Methods In a multicentre prospective cohort study, viral load (VL) and drug resistance mutations (DRMs) were investigated at baseline and 6 monthly intervals in children (age ≤ 12 years). VF (two consecutive VLs >1000 copies/mL or death after 6 months of ART) was defined as early VF (0–24 months of ART) or late VF (25–48 months of ART). An active regimen was defined as partially active if the genotypic susceptibility score (GSS) was <3. Results Between 2010 and 2011, 316 children were enrolled. Viral suppression was achieved in 75.8%, 71.5%, 72.6% and 69.2% at 12, 24, 36 and 48 months. VF occurred in 111/286 (38.8%), of which 67.6% was early and 32.4% late VF. Early VF was associated with a partially active regimen at baseline (OR 6.0, 95% CI 1.9–18.5), poor adherence (OR 3.1, 95% CI 1.3–7.4) and immunodeficiency (OR 3.3, 95% CI 1.1–10.2). Late VF was associated with age >3 years (OR 2.5, 95% CI 1.0–6.6) and WHO stage 3/4 (OR 4.2, 95% CI 1.4–13.4). Acquired DRMs were detected in 27.0% before 24 months, versus 14.4% after 24 months (P < 0.001). A total of 92.2% of the children with early VF, versus 56.2% with late VF, had a partially active regimen (P < 0.001). Conclusions VF rates were high, occurred predominantly in the first 24 months and appeared to increase again in year four. Risk factors and patterns of early VF/DRMs were different from those of late VF/DRMs. Virological control may improve by close monitoring and prompt switching to second-line therapy in the first 24 months. Late VF may be prevented by early start of ART.