Genotypic resistance at viral rebound among patients who received lopinavir/ritonavir-based or efavirenz-based first antiretroviral therapy in South Africa.

NNRTI drug resistance mutations (DRM) are increasingly reported in Africans failing their first antiretroviral regimen. The Phidisa II trial randomized treatment-naive participants to LPV/r or EFV with d4T+3TC or ZDV+ddI. We report the prevalence of DRM in subjects who achieved HIV RNA 1000 copies/mL. Sixty-eight participants fulfilled the inclusion criteria. NNRTI-DRM were found in 17/36 (47.2%) EFV-recipients, and M184V/I mutation in 14/40 (35.0%) 3TC-recipients. No PI mutation was identified in 38 LPV/r-recipients. This is one of the first studies in Africa confirming the paucity of PI-associated DRM despite virologic failure.