Prevalence and patterns of transmitted drug resistance in HIV-infected adult patients initiating antiretroviral therapy in Hanoi, Vietnam

Abstract

As antiretroviral therapy (ART) coverage for HIV-infected patients in Vietnam continues to increase, data on the prevalence and patterns of transmitted drug resistance (TDR) mutations are important to guide national ART strategies. TDR was evaluated in 345 antiretroviral-naïve patients consecutively initiating first-line ART in the clinical trial of Virological Monitoring in Vietnam (VMVN) at Bach Mai Hospital in Hanoi between April 2011 and October 2013. TDR mutations were identified by Sanger sequencing of HIV pol gene and were defined based on the 2009 World Health Organization surveillance drug resistance mutation (SDRM) list. 330 plasma samples were successfully sequenced in both protease and reverse transcriptase regions of HIV pol gene. 323 samples were subtype CRF01_AE; two were subtype A/CRF01_AE, two were subtype BC, one was subtype C; one was subtype F/C recombinant. SDRMs were identified in 16 (4.8%) patients. Among them 6 (38%) patients carried mutations conferring resistance to nucleoside/tide reverse transcriptase inhibitors (NRTIs) (K70E, V75M, K219N/E, T215S), 5 (31%) to non-nucleoside reverse transcriptase inhibitors (NNRTIs) (K101E, K103N, Y181C, G190A), 4 (25%) to protease inhibitors (PIs) (M46I/L, I54L, L90M), and one to both NRTIs and NNRTIs (L74I, V75M, M184V, T215F, K101E, G190A). The level of TDR remains low despite the rapid scale up of ART in Vietnam over the past 10 years. TDR to PIs was identified in 4 patients for the first time in Ha Noi. As PIs are the main component of 2nd-line therapy and the last resort for patients with drug-resistant virus in Vietnam. The detection of TDR to PIs is of concern and requires further investigation.