HIV viral suppression and longevity among a cohort of children initiating antiretroviral therapy in Eastern Cape, South Africa

Abstract

Introduction: There are limited data on viral suppression (VS) in children with HIV receiving antiretroviral therapy (ART) in routine care in low-resource settings. We examined VS in a cohort of children initiating ART in routine HIV care in Eastern Cape Province, South Africa.

Methods: The Pediatric Enhanced Surveillance Study enrolled HIV-infected ART eligibility children zero to twelve years at five health facilities from 2012 to 2014. All children received routine HIV care and treatment services and attended quarterly study visits for up to 24 months. Time to VS among those starting treatment was measured from ART start date to first viral load (VL) result <1000 and VL <50 copies/mL using competing risk estimators (death as competing risk). Multivariable sub-distributional hazards models examined characteristics associated with VS and VL rebound following suppression among those with a VL >30 days after the VS date.

Results: Of 397 children enrolled, 349 (87.9%) started ART: 118 (33.8%) children age <12 months, 122 (35.0%) one to five years and 109 (31.2%) six to twelve years. At study enrolment, median weight-for-age z-score (WAZ) was -1.7 (interquartile range (IQR):-3.1 to -0.4) and median log VL was 5.6 (IQR: 5.0 to 6.2). Cumulative incidence of VS <1000 copies/mL at six, twelve and twenty-four months was 57.6% (95% CI 52.1 to 62.7), 78.7% (95% CI 73.7 to 82.9) and 84.0% (95% CI 78.9 to 87.9); for VS <50 copies/mL: 40.3% (95% CI 35.0 to 45.5), 63.9% (95% CI 58.2 to 69.0) and 72.9% (95% CI 66.9 to 78.0). At 12 months only 46.6% (95% CI 36.6 to 56.0) of children <12 months had achieved VS <50 copies/mL compared to 76.9% (95% CI 67.9 to 83.7) of children six to twelve years (p < 0.001). In multivariable models, children with VL >1 million copies/mL at ART initiation were half as likely to achieve VS <50 copies/mL (adjusted sub-distributional hazards 0.50; 95% CI 0.36 to 0.71). Among children achieving VS <50 copies/mL, 37 (19.7%) had VL 50 to 1000 copies/mL and 31 (16.5%) had a VL >1000 copies/mL. Children <12 months had twofold increased risk of VL rebound to VL >1000 copies/mL (adjusted relative risk 2.03, 95% CI: 1.10 to 3.74) compared with six to twelve year olds.

Conclusions: We found suboptimal VS among South African children initiating treatment and high proportions experiencing VL rebound, particularly among younger children. Greater efforts are needed to ensure that all children achieve optimal outcomes.

Keywords: antiretroviral therapy; late ART initiation; paediatric HIV; viral load; viral load rebound; viral load suppression.