Prevalence of drug resistance and newly recognised treatment-related substitutions in the HIV-1 reverse transcriptase and protease genes from HIV-positive patients naïve for anti-retrovirals.

The aim of this study was to assess the prevalence of genetic changes in either the HIV reverse transcriptase (RT) or protease (Pro) genes in a cohort of patients naïve for anti-retroviral therapy. Of 61 patients, 43 (70.5%) were infected with HIV strains harbouring at least one resistance-related mutation, with 41 (67.2%) harbouring newly recognised treatment-related mutations. Among the 61 patients, the prevalence of specific mutations in the RT gene was as follows: 39A, 1.6%; 43E, 1.6%; and 228H, 1.6%. The prevalence of specific mutations in the Pro gene was as follows: 11I, 1.6%; 13V, 26.2%; 35D, 19.6%; 45R, 1.6%; 58E, 1.6%; 62V, 31%; 72V, 11.4%; 72M, 6.5%; 72T, 3.2%; 75I, 1.6%; and 89M, 13%. A higher prevalence of newly recognised mutations was found in strains from patients infected through sexual practices (30/36 = 83.4% vs. 11/25 = 44%; p 0.0023; OR 10.91; 95% CI 3.14-40.39). These findings support the use of resistance testing in patients naïve for anti-retroviral therapy, and suggest that the possible impact of newly recognised treatment-related mutations on clinical outcome requires further investigation.