Suboptimal adherence associated with virological failure and resistance mutations to first-line highly active antiretroviral therapy (HAART) in Bangalore, India

Abstract This study was conducted to examine the relationship between adherence, viral load (VL) and resistance among outpatients receiving highly active antiretroviral therapy (HAART) in Bangalore, India. In total, 552 outpatients were recruited and VL testing was conducted for all study participants. HIV-1 genotypic resistance testing was performed for 92 participants with a VL > 1000 copies/ml. Interpretation of resistance mutations was performed according to the Stanford database. Past-month adherence and treatment interruptions for >48 h were assessed via self-report. At baseline, 34 participants (6%) reported 48 h treatment interruptions. Combining the two adherence measures, 22% of participants were classified as ‘suboptimally adherent’. In total, 24% of study participants ( n =  132) had a detectable VL. Among the 92 samples sent for resistance testing, 68% had at least one nucleoside reverse transcriptase inhibitor (NRTI) mutation, with M184 V being the most common (65%) and with 48% having thymidine analogue mutations. Moreover, 72% had at least one non-nucleoside reverse transcriptase inhibitor (NNRTI) mutation and 23% had three or more NNRTI mutations. Both adherence measures were significantly associated with VL ( P P