Introduction: Viral load (VL) testing is essential for monitoring the effectiveness of antiretroviral therapy (ART) in children living with HIV. Zambia has national guidelines supporting routine VL monitoring, but gaps in testing access and result utilization may hinder optimal paediatric HIV care. Despite high VL access, utilization for clinical decisions remains suboptimal.

Materials and methods: A cross-sectional analytical study was conducted among 290 HIV-positive children aged 0–10 years receiving ART across 25 health facilities in Eastern Province, Zambia, from January 2024 to January 2025. Retrospective data were collected from SmartCare and facility records, focusing on VL testing access, suppression outcomes, ART regimen, adherence, and treatment duration. Statistical analyses included Chi-square tests and multivariate logistic regression. Virological suppression was defined as plasma viral load <1,000 copies/mL and virological failure as ≥1,000 copies/mL on two consecutive measurements, at least three months apart, with adherence support between tests, in accordance with WHO guidelines.

Results: VL testing access was recorded in 98.3% (n = 285) of the children, with 84.8% (n = 246) achieving virological suppression. Suppression was 86.3% among those with access to testing, compared to 0% in those without. A significant association was found between VL access and suppression (χ²(1) = 20.42, p < 0.001). After adjusting for adherence and duration on ART, VL access remained a significant predictor of suppression. However, delayed regimen switches and inconsistent documentation in cases of virological failure (15.2%) negatively impacted outcomes.