Updates on the clinical epidemiology of HIV-1 group O strains in Cameroon and potential implications on diagnosis and treatment strategies

Abstract

Cameroon is an epicentre of diverse HIV-1 strains, with challenges in diagnosis and disease management. The objective herein was to update the prevalence of HIV-1 non-M and compare diagnostic-performance of the 2-test vs. 3-test algorithms. A facility-based study was conducted in February 2024 on 2207 HIV-1 clinical-samples at the Chantal BIYA International Reference Centre, Yaoundé-Cameroon. Molecular-phylogeny and rapid-subtyping were performed for identifying HIV-1 non-M. Performances of rapid diagnostic tests (RDTs) used in the 2-test (determine and KHB) vs. 3-test (First Response, One Step and KHB) algorithms were evaluated on non-M, with ACRO Rapid Test (HIV1/2&p24) as independent RDT. No group-N (0%) nor P (0%) were found while 09 group-O strains were identified (0.4%; 95%CI: 0.2%-0.8%). For individuals harbouring group-O, (mean-age, 43±12 years; 50% female) median [IQR] duration since HIV-diagnosis was 627 [423-775] weeks, median [IQR] viremia, 12 385 [5 340-72 682] copies/ml and median [IQR] CD4 count [IQR], 52 [39-228] cells/mm³. One Step, KHB and ACRO Rapid Test (HIV1/2&p24) detected 8/8 group-O (100%-performance), First Response HIV1-2.0, 7/8 (87.5%-performance) and Determine HIV1/2, 6/8 (75%-performance), p=1.00. In this Cameroonian setting, HIV-1 group-N and P are scarce while group-O remains low (<1%). Transitioning from the 2-test (75%-performance) to the 3-test algorithm (87.5%-performance) could lead to improved diagnostic performance on currently circulating HIV-1 group-O, calling for updates in RDTs to adapt to viral dynamics.