PREVALENCE AND FACTORS ASSOCIATED WITH FALSE NEGATIVE RAPID DIAGNOSTIC HIV TESTS AMONG PATIENTS ON ANTIRETROVIRAL THERAPY WITH A NON-DETECTABLE VIRAL LOAD IN KAMPALA, UGANDA: A CROSS-SECTIONAL STUDY

Abstract

ABSTRACT Background Evidence emerging from Sub-Saharan Africa indicates that people living with HIV (PLHIV) on long-term antiretroviral therapy (ART) especially when the viral load is undetectable, may falsely test negative for HIV on rapid diagnostic tests. This study assessed the prevalence and factors associated with false negative rapid diagnostic HIV tests among Patients on antiretroviral therapy, with undetectable viral load levels at Kisenyi Health Center IV, Kampala, Uganda. Methods Between October 2023 and February 2024, a cross-sectional study was conducted among 1,248 PLHIV on ART with undetectable viral loads at Kisenyi Health Center IV. Participants were recruited consecutively, and HIV re-testing was conducted in accordance with the national serial rapid testing algorithm. The algorithm includes a screening test (Determine™ HIV-1/2), a confirmatory test (Stat-Pak®), and a tie-breaker test (SD Bioline®). Enzyme-linked immunosorbent assay (ELISA) was used as the final confirmatory method. Data on socio-demographics and clinical characteristics was collected using an electronic data abstraction tool. Logistic regression analysis was done to assess for factors associated with false negative results, using STATA version 14.0. Results The median age of the participants was 34.0 (interquartile range 29.0-42.5 years). The prevalence of false-negative rapid test results was 3.2% (40/1248; CI:2.20-4.2). CD4 (aOR 1.001, CI:1.001-1.003) and duration on ART (aOR 0.884, CI:0.801-0.978) were significantly associated with false-negative HIV results. Conclusion False-negative results were observed in approximately 3 in every 100 PLHIV on ART with an undetectable viral load. Serial rapid testing alone may be suboptimal for detecting HIV infection in this population. Further confirmatory testing in individuals who test negative on rapid testing is recommended.