INTRODUCTION

in order to promote rapid care of HIV-positive people and to reduce the human immunodeficiency virus (HIV) transmission in Gabon, the national screening algorithm is essentially based on rapid diagnostic tests (RDTs). However, most of these RDTs are not evaluated. Their sensitivities and specificities remain unknown locally. The aim of this study was to determine the diagnostic performance of 3 RDTs used for HIV-1> screening in Gabon.

METHODS

of the one hundred and sixteen (116) samples tested, 60 plasmas were HIV-1 positive with known genotypes and viral loads; 51 sera were HIV-1 negative while 5 had an undetermined serological status. All the samples were tested by quantitative RT-PCR (Gold standard) and by the following RDTs: Vikia, Alere Combo and Alere Determine. The sensitivities and specificities of the different RDTs were calculated using Epi Info version 6.04dfr. The level of agreement between tests was determined by Cohen´s Kappa test.

RESULTS

the three RDTs´ sensitivity according to HIV-1/M subtypes was 100% (95% CI: 92.6-100) while their specificities ranged from 94.6% (95% CI: 84.2-98.6) for the Vikia test to 96.4% (95% CI: 86.6-99.4) for the Alere Combo and Alere Determine tests, respectively. The concordances between the three RDTs were excellent with kappa values ranging from 0.931 (95% CI: 0.864-0.977) to 0.948 (95% CI: 0.890-1.00).

CONCLUSION

the three RDTs showed a maximum sensitivity of 100% and specificities ranging from 94.6% to 96.4%. The specificities obtained with these RDTs are lower than those recommended by the WHO for their inclusion in an HIV-1 screening algorithm.