Surveillance of HIV-1 Antiretroviral Drug Resistant Strains in Thailand

Abstract

In this study, surveillance of HIV-1 drug resistance was conducted on 307 AIDS/HIV infected patients who received ART for more than 6 months from 14 provinces in all parts of Thailand. Most of the patients were treated with GPO-VIR (67.7%), other NRTIs+NNRTIs regimens (23.1%) and only 7.2% of patients were treated with PIs regimens. All plasma samples of 307 patients were assessed for viral load level and 37 patients had viral load > 1,000 copies/ml that were further analyzed for HIV drug resistance by genotyping assay. The highest frequency of NRTI drug resistant mutation was M184V (97.1%) that associated with resistance to 3TC in 34 patients. Thymidine analogue-associated mutations (TAMs) were M41L (22.8%), D67N (34.3%), K70R (14.3%), L210W (11.4%), T215F (31.4%), K219R (20.0%). Mutations that associated with NNRTI drug resistance were A98G (14.3%), K101E (22.8%), K103N (34.3%), V108I (22.8%), Y181C (42.8%), Y188L (5.7%), G190S (34.3%) and P225H (8.6%). Resistance to NVP and EFV were found in 34 and 20 patients respectively. PIs-associated mutations were found in all 37 patients but only one patient was resistant to PIs. In conclusion, the percentage of ARV drug resistance were 11.4% (35/307) in all treated patients, 14.5% (18/124) in patients treated for > 3 years and 13.3% (8/60) in patients treated for >1-2 years.