Low emergence of secondary antiretroviral drug resistance mutations among HIV‐1 subtype C‐infected Ethiopian patients

Abstract

Background: The emergence of HIV-1 drug resistance mutations has been mainly linked to the duration and composition of antiretroviral treatment (ART) as well as the level of adherence. In Ethiopia, firstline ART with NRTI and NNRTI was introduced in 2005 and PI in limited access was available since 2009. This study reports the emergence and pattern of secondary antiretroviral drug resistance mutations and long-term outcomes of ART. Methods: 127 HIV-infected treatment-naïve patients initiating ART at AIDS clinic of University of Gondar, Ethiopia were enrolled and followed for up to 36 months on ART. HIV viral load and drug resistance mutations were determined at baseline and after a median time of 30 months on ART using Abbott qRealTime HIV-1 assay and an in-house protocol, respectively. Genotypic drug resistance mutations were interpreted according the Stanford University drug resistance database [http://hivdb.stanford.edu] and to the IAS mutation list [http://iasusa.org/resistance-mutation]. Results: The mean baseline HIV viral load was 4.3091.03 log10 copies/ml. Viral suppression rate (HIV RNA levels B2.60 log10 copies/ml) after a median time of 30 months (range: 21-37) was found to be 88.2% (112/127). Of the patients with viral load >2.60 log10 copies/ml, six had harboured one or more drug-resistant associated mutation on RT region. The observed NRTI resistance associated mutations were the lamivudine-induced M184V mutation (n =4) and tenofovir-associated mutation K65R (n=1). The NNRTI resistance-associated mutations were K103N (n=2), V106M, Y181S, Y188L, V90I, K101E and G190A (n=1 each). Thymidine analogue mutations and major drug resistance mutation on PR region were not yet detected. Most of the patients with virologic failure and accumulated drug resistance mutations had not met the WHO clinicoimmunologic failure criteria and continued the failing regimen. Conclusions: The incidence and pattern of secondary antiretroviral drug resistance mutation is low and less complex than has been previously reported in sub-Saharan Africa. However, the data suggest the need for virological monitoring and resistance testing for early detection of ART failure.