Virological suppression among people living with HIV monitored through routine viral load testing in seven districts of Western Province, Zambia: a geospatial and programmatic analysis of kaoma pcr laboratory data, January-December 2025

Abstract

Achieving and sustaining virological suppression among people living with HIV (PLHIV) receiving antiretroviral therapy (ART) is essential for improving clinical outcomes, reducing HIV transmission, and achieving the UNAIDS 95-95-95 targets. Although Zambia has expanded routine viral load (VL) monitoring, disparities in virological suppression persist across districts. This study assessed virological suppression among PLHIV whose routine VL samples, collected from health facilities in seven districts of Western Province and tested at the Kaoma PCR Laboratory, using routine laboratory data from January to December 2025 to characterize geographic variation and inform targeted HIV program interventions. We conducted a retrospective cross-sectional study using de-identified routine HIV viral load records from the Kaoma PCR Laboratory for seven districts in Western Province, Zambia, between January and December 2025. Virological suppression was defined as a plasma viral load of < 1,000 copies/mL. Descriptive statistics were used to summarize participant characteristics and viral load suppression. Differences in suppression by age and sex were assessed using Pearson’s chi-square test, while district-level variation was visualized using geographic information system (GIS) mapping. A total of 31,288 routine VL records were analysed, of which 22,386 (71.6%) were from females and 27,779 (88.7%) were from adults aged ≥ 25 years. Overall, 93.4% (95% CI: 93.2–93.7) of clients achieved virological suppression (< 1,000 copies/mL). Virological suppression differed significantly by age (χ² = 311.49, p < 0.001), with the highest suppression among adults aged ≥ 25 years (94.3%; 95% CI: 94.0–94.6) and the lowest among children aged 0–4 years (83.1%; 95% CI: 76.3–88.3). Suppression was also significantly higher among females than males (94.1% vs. 91.8%; χ² = 54.74, p < 0.001). All seven districts achieved suppression rates above 91%, ranging from 91% in Sikongo to 95% in Nkeyema. However, only 30 of 140 (21.4%) health facilities achieved the UNAIDS target of ≥ 95% viral suppression. Virological suppression was high among PLHIV receiving routine viral load testing in the seven study districts. However, lower suppression among children, adolescents, young adults, males, and many health facilities highlights the need for targeted interventions to improve treatment outcomes and achieve the UNAIDS viral suppression target. Not applicable.