Weerawat ManosuthiSupeda ThongyenSamruay NilkamhangSukanya ManosuthiSomnuek SungkanuparphThailand Ministry of Public HealthMahidol University2018-10-192018-10-192013-02-01Journal of Medical Virology. Vol.85, No.2 (2013), 194-19910969071014666152-s2.0-84871045834https://repository.li.mahidol.ac.th/handle/123456789/31966Antiretroviral therapy (ART) has increased in resource-limited settings. This study determined the prevalence of HIV-1 drug resistance-associated mutations (DRAMs) among patients with chronic HIV-1 infections and compare DRAMs between CRF01_AE and B subtypes. ART-naive Thai patients who had ART initiation between 2010 and 2011 were enrolled prospectively. Genotypic assays were performed on viral reverse transcriptase and protease genes within 4 weeks before starting ART. DRAMs were assessed using the International AIDS Society-USA 2011 list. A total of 330 patients were included. HIV-1 subtypes included CRF01_AE (73%), B (23.9%), and others (3.1%). Median (IQR) CD4+ was 66 (23-172)cells/mm3 and median (IQR) HIV-1 RNA was 5.2 (4.6-5.8) log copies/ml. The prevalence of patients with ≥1 DRAMs for any antiretroviral agents was 17.6%. DRAM prevalence was 17% for non-nucleoside reverse transcriptase inhibitors (NNRTIs), 0.6% for NRTIs, and 0.6% for protease inhibitors (PIs). DRAMs to NNRTIs were V106I (7%), V179D (4.2%), V179T (1.8%), E138A (1.5%), V90I (1.2%), K103N (0.9%), Y181C (0.9%), and P225H (0.3%). DRAMs to NRTIs were M184V (0.3%) and T215S (0.3%). The only major DRAM for PIs was M46L (0.6%). Minor DRAMs to PIs including I13V, M36I, H69K, and L89M were observed more frequently in CRF_01 AE. By multivariate analysis, the factors "HIV-1 subtype B" and "low pretreated CD4+ cell count" were associated with a higher rate of DRAMs. HIV-1 DRAMs, especially to NNRTIs, are emerging in a middle-income country after widespread use of NNRTI-based ART. HIV genotypic assays before ART initiation in patients with chronic HIV-1 infection should be considered. J. Med. Virol. 85:194-199, 2013. © 2012 Wiley Periodicals, Inc. Copyright © 2012 Wiley Periodicals, Inc.Mahidol UniversityImmunology and MicrobiologyMedicineArticleSCOPUS10.1002/jmv.23452