Performance of the VISITECT® CD4 Test for Rapid Identification of Advanced HIV Disease at AHF-Supported Sites in Zambia: A Diagnostic Accuracy Analysis in a Zambian Population
Listed in
This article is not in any list yet, why not save it to one of your lists.Abstract
Background
Advanced HIV disease (AHD), defined as a CD4 count below 200 cells/mm³ or the presence of WHO Stage 3 or 4 clinical conditions, poses significant diagnostic challenges in resource-limited settings such as Zambia. Early identification of AHD is essential for improving outcomes for recipients of care (ROCs). The VISITECT® CD4 test, a point-of-care tool, offers potential for addressing these challenges; however, its diagnostic performance in Zambia remains under-evaluated. This study aimed to assess the sensitivity and specificity of the VISITECT® CD4 test for identifying AHD among ROCs at five AIDS Healthcare Foundation (AHF)-supported clinics in Zambia.
Methodology
A cross-sectional study was conducted between January 8 to May 31, 2024, at five AHF-supported clinics in Zambia. Participants included individuals who were newly diagnosed with HIV, re-engaging in HIV care, or presenting with unsuppressed HIV viral loads. Baseline clinical and demographic data were collected, and the diagnostic performance of the VISITECT® CD4 test was compared to the flow cytometry CD4 test (the gold standard) using STATA v15 to determine sensitivity, specificity, and other diagnostic accuracy metrics.
Results
Among 231 participants, 24.7% (57/231) had AHD based on the flow cytometry CD4 test, whereas 47.6% (110/231) were classified with AHD by the VISITECT® CD4 test. The VISITECT® CD4 test demonstrated a sensitivity of 96.5% and a specificity of 68.4%. The Negative Predictive Value was 98.4%, and the Positive Predictive Value was 50.0%. The overall diagnostic accuracy, as indicated by the area under the curve, was 0.82 (95% CI: 0.78, 0.87). AHD was significantly associated with age according to flow cytometry (p=0.029) but not according to the VISITECT® CD4 test (p=0.277). A significantly higher proportion of individuals with anemia had AHD across both tests (p<0.05).
Conclusion
The VISITECT® CD4 test demonstrated strong diagnostic accuracy for detecting AHD, making it a valuable rapid point-of-care tool in resource-limited settings. Its wider implementation could enhance early AHD detection and facilitate timely clinical interventions, warranting further exploration.
