Resistance to efavirenz and nevirapine has not been associated with mutations at position 138 of reverse transcriptase. In an evaluation of virologic suppression rates in PEPFAR (President's Emergency Plan For AIDS Relief) clinics in Kenya among patients on first-line therapy (RV288), 63% (617/975) of randomly selected patients on antiretroviral therapy were suppressed (HIV RNA<400 copies/ml). Among those with non-nucleoside reverse transcriptase inhibitor resistance (n = 101), 14 (13.8%) had substitutions at 138 (A, G, K or Q), mutations selected only by etravirine and rilpivirine in subtype B viruses. All 14 patients received efavirenz or nevirapine, not etravirine or rilpivirine, and were predominantly subtype A1. This may be the first report of efavirenz and nevirapine selecting these mutations in these subtypes.
aU.S. Military HIV Research Program, Global Health Programs, Walter Reed Army Institute of Research, Silver Spring
bHenry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, Maryland, USA
cKenya Defense Forces (KDF), United States Army Medical Research Unit – Kenya (USAMRU-K), Nairobi, Kenya
dKenya Medical Research Institute (KEMRI)/Walter Reed Program, South Rift Valley (SRV), US Army Medical Research Unit-Kenya (USAMRU-K), Kerich, Kenya
eSouthern Highlands Walter Reed Program, Mbeya, Tanzania.
Correspondence to Keith Crawford, PhD, RPh, US Military HIV Research Program/Walter Reed Army Institute of Research, Bethesda, Maryland, USA.
Received 4 September, 2013
Revised 5 November, 2013
Accepted 5 November, 2013