Anti-HIV Serological Profiles and Concordance of Chemiluminescent Immunoassay Screening With a Supplemental Rapid Test Among Blood Donors in Côte d'Ivoire.

INTRODUCTION: HIV screening by chemiluminescent immunoassay (CLIA) enables the simultaneous detection of anti-human immunodeficiency virus (HIV)-1/2 antibodies (Abs) and the p24 antigen (Ag), ensuring high sensitivity and specificity. Viral typing is essential for the clinical follow-up of seropositive blood donors. This study aimed to identify anti-HIV Ab profiles among blood donors who tested positive by CLIA and to assess the concordance between CLIA screening and supplemental rapid testing. METHODS: A descriptive study was conducted at the Regional Blood Transfusion Center of Bouaké from November 2024 to February 2026. Blood donors were screened for HIV using two CLIA platforms (MAGLUMI and MACCURA). The testing algorithm consisted of CLIA screening, followed by HIV Bioline rapid testing for serological typing and a follow-up test on a new blood sample. CLIA-reactive samples were classified as concordant reactive when confirmed by the HIV Bioline test and as presumed false positives when the initial CLIA-reactive result was not confirmed by HIV Bioline and became non-reactive on repeat CLIA testing on a new sample. RESULTS: Among 21,643 blood donors screened, 79 (0.37%) were reactive by CLIA. A male predominance was observed (sex ratio: 2.8). The mean age was 33.9 years in men and 31 years in women. Of these, 44/79 (55.7%) were classified as concordant reactive, 19/79 (24.1%) as presumed false positives, and 16/79 (20.2%) as indeterminate (CLIA-reactive but HIV Bioline-negative pending follow-up). Among the confirmed reactive samples, 34 (43.0%) were infected with HIV-1, 1 (1.3%) with HIV-2, and 9 (11.4%) had HIV-1/HIV-2 dual infection. Two cases of hepatitis B co-infection were also identified. The MAGLUMI assay showed a specificity of 99.93%, a proportion of concordant reactive results of 77.5%, and a presumed false-positive rate of 0.07%, whereas the MACCURA assay showed a specificity of 99.87%, a concordance of 65%, and a presumed false-positive rate of 0.13%. Signal-to-cutoff (S/CO) ratios were higher in concordant reactive samples (1.89-500) than in presumed false-positive samples (1.03-11.56). CONCLUSION: Despite their high performance, CLIA assays require confirmatory testing to determine the HIV type (HIV-1 or HIV-2), reduce false-positive results, and ensure a reliable diagnosis.