Persistence of K103N-containing HIV-1 variants after single-dose nevirapine for prevention of HIV-1 mother-to-child transmission

K103N-containing human immunodeficiency virus (HIV)-1 variants are selected in some women who receive single-dose (SD) nevirapine (NVP) for prevention of HIV-1 mother-infant transmission. We examined the persistence of K103N in women who received SD NVP prophylaxis. K103N was detected using the LigAmp assay (assay cutoff, 0.5% K103N). K103N was detected at 6-8 weeks in 60 (41.7%) of 144 women. Fading (lack of detection) of K103N was documented in 16 women by 2 years, 43 women by 3 years, and 55 women by 4 and 5 years. Slower fading was independently associated with HIV-1 subtype (D>A) and higher pre-NVP viral load. © 2007 by the Infectious Diseases Society of America. All rights reserved.