Abstract
BACKGROUND: Undernutrition remains a major public health concern among HIV-positive children. Despite advancements in antiretroviral therapy (ART) effectiveness in managing HIV, these children still face nutritional challenges that impact their overall health. This study sought to determine the prevalence and identify the factors associated with undernutrition among HIV-positive children attending ART clinics in Bushenyi District, western Uganda. METHODS: Multi-facility based cross-sectional and analytical study was conducted among HIV-positive children aged 6 months to 12 years at five ART clinics in Bushenyi District. The study carried out from November, 2024 to February, 2025, Using consecutive sampling method. Data on socio-demographic characteristics, factors associated were collected using structured questionnaires and anthropometric measurements and analyzed using STATA Version 14.2. A bivariable and multivariable binary logistic regression analysis was performed to assess factors associated with undernutrition among HIV-positive children. RESULTS: Out of 385 children studied, 177/385 (45.97%) had undernutrition. The prevalence of stunting (36.62%), underweight (24.42%), and wasting (10.91%) being the most common forms, Key predictors of undernutrition included low caregiver education (aOR = 4.54{95% CI: 2.75–8.48}, p-value < 0.001), low household income (aOR = 9.22 {95% CI:3.15–26.93}, p-value < 0.001), low birth weight (aOR = 3.48 {95% CI:1.38–8.76}, p-value = 0.008), high viral load (aOR = 7.43 {95% CI:2.37–23.34}, p-value = 0.001), low CD4 count (aOR = 5.69 {95% CI: 1.81–17.90}, p-value = 0.003), ART duration < 12 months (aOR = 7.80 {95% CI: 2.33–26.10}, p-value = 0.001), missed ART doses > 5 doses (aOR = 8.45 {95% CI: 2.32–30.74}, p-value = 0.001), and opportunistic infections (aOR = 8.26 {95% CI:3.70–18.44}, p-value < 0.001). CONCLUSION: The prevalence of undernutrition was high. With significant rates of stunting, underweight, and wasting. Sociodemographic and clinical factors, including caregiver education, household income, ART adherence, and viral load and opportunistic infection, also played critical roles in undernutrition. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40795-026-01298-0.