High prevalence of genotypic and phenotypic HIV-1 drug-resistant strains among patients receiving antiretroviral therapy in Abidjan, Cote d'Ivoire

To describe prevalence of antiretroviral (ARV) drug-resistant HIV-1 strains among patients with a history of earlier treatment with ARV drugs in Abidj an, Cote d'Ivoire. we determined mutations that confer HIV-1 ARV drug resis tance by sequencing the viral reverse-transcriptase and protease genes deri ved from plasma viral RNA of 68 individuals consecutively enrolled in the J oint United Nations Program on AIDS Drug Access Initiative (UNAIDS-DAI) wit h a history of earlier ARV drug treatment in Abidjan between August 1998 an d April 1999. Phenotypic ARV drug resistance was assessed using a recombina nt virus assay. Primary mutations associated with ARV drug resistance to at least one of the reverse-transcriptase inhibitors or protease inhibitors w ere detected in 39 (57.4%) of the 68 patients. The prevalence of mutations associated with resistance to ARV drugs was: 29 (42.6%) to zidovudine, 10 ( 14.7%) to lamivudine, one (1.5%) to didanosine, one K103N mutation (associa ted with resistance to delavirdine, nevirapine, and efavirenz), one Y181C m utation (associated with resistance to delavirdine and nevirapine). two to both indinavir (M46I/L and V82A) and saquinavir (G48V and L90M). and one ea ch to ritonavir (V82A) and nelfinavir (D30N). Phenotypic resistance to at l east one nucleoside reverse transcriptase inhibitor (RTI) was seen in 25 (3 9.7%) patients, to nonnucleoside RTIs in 5 (8%) patients. and to protease i nhibitors in 4 (6%) patients. The high prevalence we observed in this study may limit in future the effectiveness of ARV programs in the Cote d'Ivoire .