Evaluation of four rapid tests to detect HIV recent seroconversion
Background: HIV incidence estimation represents a challenge to health authorities and carries a substantial cost. The use of rapid tests to identify recent seroconversion may be an alternative for studies of HIV incidence once they do not require complex laboratory infrastructure and are easily performed. This study assessed the feasibility of four rapid HIV tests which were modified in order to reduce its sensitivity (detuned), aiming the detection of recent seroconversion.
Methods: As gold standard, BED-CEIA assay (Calypte HIV-1 BED Incidence EIA Capture) which allows distinguishing patients with recent infection (less than 154 days) from patients with HIV chronic infection was carried out. Initially, the following rapid tests were evaluated: VIKIA® HIV-1/2, Rapid Check HIV 1 & 2, Teste Rápido DPP® HIV-1/2 Bio-Manguinhos and HIV-1/2 3.0 Strip Test Bioeasy. Dilutions with high concordance between rapid tests and gold standard were chosen. Rapid Check and Bioeasy were excluded due to discrepant results during dilution standardization. 213 HIV positive samples by two serological tests were selected, being 91 recent and 122 chronic by BED-CEIA assay. The samples were tested with VIKIA® (dilution 1:1100) and Bio-Manguinhos (dilution 1:560) assays.
Results: VIKIA® and Bio-Manguinhos tests results presented a concordance of 75.6% (95% CI: 71.6 to 76.9; Kappa = 0.465) and 77.9% (95% CI: 73.2 - 80.5; Kappa = 0.525), respectively. VIKIA® assay misclassified 52 samples and Bio-Manguinhos 47 samples.
Conclusions: The applicability of rapid tests in classifying recent and chronic infection has not been established and there is a lack of rapid tests designed to diagnose recent infection. Data showed the evaluated rapid tests are not recommended for detecting recent seroconversion, enlightening the need of developing standardized rapid tests which can be used as tools to estimate incidence of HIV infection.
G.E. Cuccarolo, A.C. Vanni, L.R. Motta, L.G.A. Borges, S.K. Kato, R.D. Sperhacke
Universidade de Caxias do Sul, Laboratório de Pesquisa em HIV/AIDS, Centro de Ciências da Saúde, Caxias do Sul, Brazil