Predictors of high viral load among adult HIV recipients of care in Zambia, 2021: a cross-sectional analysis of HIV case-based surveillance data


BACKGROUND: Controlling the HIV epidemic in Zambia will require achieving high viral suppression coverage, as outlined by UNAIDS 95-95-95 targets. Identifying and characterizing predictors of high viral load among recipients of care (RoC) could help guide development of interventions critical to improving HIV treatment outcomes.
METHODS: We conducted a cross-sectional analysis of HIV case-based surveillance data from January to December 2021 of adult RoC ('¥15 years) in Zambia with record of receiving antiretroviral therapy (ART) for '¥ 6 months and latest valid viral load (VL) measurement per national electronic health record. We assessed association of sociodemographic characteristics and ART duration on 31 December 2021, with high VL load, defined as >1,000 copies RNA/mL, based on the latest VL measurement in 2021. Regression analyses were conducted to estimate unadjusted and adjusted odds ratios to estimate effects of covariates independently associated with high VL.
RESULTS: A total of 531,864 HIV RoC met inclusion criteria with majority (64.8%) female, median age of 35 years (interquartile range [IQR] 29-42), and median ART duration of 52 months (IQR: 29-99). High VL occurred in 18,540 (3.49%) RoC, of whom 11,083 (59.90%) were females, and 13,822 (74.55%) had been on ART for > 18 months. Factors independently associated with high VL included: being male (adjusted odds ratio [aOR]=1.42, 95% confidence interval [CI]: 1.37-1.46), younger age: 15-19 (aOR=2.68, 95% CI: 2.52-2.85), 20-24 (aOR=1.78, 95% CI: 1.70-1.86), 25-29 (aOR=1.40, 95% CI: 1.35-1.46) compared to those > 30 year; shorter ART duration: 6 months (aOR =4.54 95% CI: 3.99-5.17), 7-12 months (aOR =2.75, 95% CI: 2.64-2.87), 13-18 months (aOR =1.42, 95% CI: 1.35- 1.49) compared > 18 months; and rural setting (aOR=1.15, 95% CI: 1.10- 1.19) compared to urban setting.
CONCLUSIONS: We identified being new on ART, male and young adult as predictors of high VL and intensifying activities centered on service delivery models for these risk groups will help the Country in its efforts to achieve high viral suppression coverage. Further evaluation of health services in rural settings may identify gaps in HIV service delivery. Identifying pathways for high VL among identified sub-populations may represent an opportunity to reach the UNAIDS 95-95-95 targets.