Frequency of protease and reverse transcriptase drug resistance mutations in naïve HIV-infected patients.

Background: Infections with drug-resistant HIV viruses in naïve subjects may cause antiretroviral (ARV) treatment failure. The prevalence of ARV resistance mutations in HIV-1 transcripts of infected naïve patients from northeast Mexico was determined in this study.

Methods: RNA was extracted from plasma samples of 42 naïve individuals who were diagnosed between February 2001 and September 2003 as HIV-1 infected. Both protease (Pr) and reverse transcriptase (RT) were sequenced in 30 patients. In six samples only the RT segment was sequenced and in three samples only the protease segment was analyzed.

Results: One of 36 isolates (2.8%) had the M184V resistance mutation to nucleoside retrotranscriptase inhibitors. In the Pr segment, only minor mutations were detected in 27/33 isolates (81.8%).

Conclusions: In this first study, prevalence of major mutations associated with ARV resistance in naïve patients in northeast Mexico is low compared to other countries, perhaps due to a low level of exposure of this population to ARV drugs.