SURVEILLANCE OF HIV-1 DRUG-RESISTANCE MUTATIONS IN THAILAND FROM 1999 TO 2014.

Antiretroviral resistance has long been a serious problem in Thailand. In order to monitor developmental rate of mutations and its impact of the national policy, frequency of drug-resistance mutations in HIV-1 reverse transcriptase (RT) and protease (PR) were analyzed from 24,279 blood plasma samples collected from 1999 to 2014. HIV-1 drug resistance mutations were influenced by drugs that have been used widely as first-line regimens. M184I/V was the most common (53.1% prevalence) RT inhibitor (NRTI) mutation. Other NRTI-associated mutations increased dramatically after the Universal Coverage Scheme was launched in 2007, but declined on the whole after introduction of the Thai National Guidelines in 2010. However, non-NRTI-associated mutations increased between 1999 and 2007, but have remained constant since, with Y181I/C the most (31.4%) prevalent. PR drug-associated mutations (M36I/L/V, H69K/R and L89I/M/V) previously considered as CRF01_AE polymorphisms constituted > 90% prevalence in all samples. The launch of antiretroviral treatment influenced the pattern of mutations and the Universal Coverage Scheme also impacted the rate of development of resistance mutations on a national scale. Drug resistance trends in Thailand could be ascribed to drug regimens that have been used for over a decade. Results from this study can be used as indicators of the success of the Universal Coverage Scheme. Knowledge of the trend of HIV drug-resistance mutations, past and present, is essential in formulating an effective antiretroviral treatment strategy.