7th Conference - Abstract 746

High Prevalence of Genotypic Antiretroviral (ART) Drug-Resistant HIV-1 Strains among HIV-1-Infected Patients Receiving ART in Abidjan, Ivory Coast

C. ADJE¹, R. CHEINGSONG-POPOV², T. ROELS^1‚2, G. DJOMAND¹, W. VERBIEST³, K. HERTOGS³, B. LARDER³, B. MONGA¹, M. PEETERS⁴, M. COULIBALY⁵, R. RESPESS², S. Z. WIKTOR², and J. N. NKENGASONG*^1‚2 for the UNAIDS HIV Drug Access Initiative Abidjan Ivory Coast. ¹Projet RETRO-CI, Abidjan, Cote d’Ivoire; ²CDC, Atlanta GA; ³VIRCO NV, Mechelen, Belgium; ⁴IRD, Montpellier, France; and ⁵UNAIDS, Abidjan, Ivory Coast

To determine the prevalence of ART drug-resistant HIV-1 strains among patients treated with ART in Ivory Coast, we selected all patients (n=68) with a history of current or past ART therapy who presented between August 1998 and April 1999 for inclusion in the UNAIDS-Sponsored Drug Access Initiative. HIV-1 plasma viral load and CD4+T cell counts were measured and genotypic drug resistance was assessed by sequencing the viral reverse-transcriptase and protease genes derived from plasma of the patients. We use the recombinant virus assay technology (antivirogram) to analyze 17 of these patients for phenotypic resistance, and HIV-1 subtypes were analyzed in a phylogenetic tree. Median (interquartile range) age of the 68 patients was 38 years (31-44), CD4+T cell count was 211 cells/mL (66-373), viral load was 4.8 log10 copies/mL (3.8 - 5.3) and duration of treatment (n=25) was 8 months (3-12). Of the 17 subset of patients assessed, 12 were infected with the IBNG-like viruses, 2 with subtype A, 1 each with subtype D, subtype A/E, and unclassifiable. Of the 68 patients, 39 (57%) had genotypic resistance to at least one reverse transcriptase inhibitor (RTI) or protease inhibitor (PI), and 15 (88%) of the patients with genotypic resistance had phenotypic resistant viruses. Specific drug resistant mutations were found in 29 (43 %) ZDV (T215Y/F, L210W, K70R, D67N, M41L), 10 (15%) 3TC (M184V/I), 1 (2%) Nevirapine (K103N, Y181C/I, G190A), 1 (2%) DMP266 (K103N), 2 (3%) each with Indinavir (M46I/L, V82A/F/T), Ritonavir (V82F/A/T/S), Saquinavir (G48V, L90M), and 1 (2%) with Nelfinavir (D30N). Our results indicate that ART drug resistance is common among patients in Abidjan with a history of ART and that this resistance amomg patients with non-subtype B infections is conferred by similar mutations to those documented for subtype B infections

Key Words: Antiretroviral, Resistance, Subtypes