Moderate prevalence of HIV-1 transmitted drug resistance mutations in southern Brazil.

BACKGROUND: Despite the advances in therapy, the occurrence of drug-resistant human immunodeficiency virus type 1 (HIV-1) is a major obstacle to successful treatment. This study aimed to characterize the genetic diversity and to determine the prevalence of transmitted drug resistance mutations (TDRM) between individuals recently or chronically diagnosed with HIV-1 from Paraná, Brazil. METHODS: A total of 260 HIV-1 positive antiretroviral therapy-naïve patients were recruited to participate on the study, of which 39 were recently diagnosed. HIV-1 genotyping was performed using sequencing reaction followed by phylogenetic analyses to determine the HIV-1 subtype. TDRM were defined using the Calibrated Population Resistance Tool program. RESULTS: The HIV-1 subtypes frequency found in the studied population were 54.0% of subtype B, 26.7% subtype C, 6.7% subtype F1 and 12.7% recombinant forms. The overall prevalence of TDRM was 6.7%, including 13.3% for recently diagnosed subjects and 5.9% for the chronic group. CONCLUSIONS: The prevalence of resistance mutations found in this study is considered moderate, thus to perform genotyping tests before the initiation of antiretroviral therapy may be important to define the first line therapy and contribute for the improvement of regional prevention strategies for epidemic control.

Frequency and diversity of human immunodeficiency virus type 1 mutations associated with antiretroviral resistance among patients from Southern Brazil failing highly active antiretroviral therapy (HAART).

The human immunodeficiency virus type 1 (HIV-1) epidemic in Brazil is spreading to small municipalities as well as the innermost parts of the country and scarce information has been reported on the frequency of HIV-1 resistance-associated mutations in these areas. To determine the frequency and diversity of the HIV-1 antiretroviral resistance-associated mutations among patients failing highly active antiretroviral therapy from Londrina in Southern Brazil, 127 HIV-1 genotyping tests that were assayed during January 2000 to July 2008 from 108 patients were evaluated. Sixty-nine patients (63.9%) were male and 39 (36.1%) were female and the age ranged from 10 to 68 years (mean, 40.8+/-9.2). All of them showed at least one HIV-1 antiretroviral resistance-associated mutation and in 72 (56.7%) genotyping tests, mutations for the three antiretroviral classes were detected simultaneously. Mutations associated with resistance to protease inhibitor (PI) were detected in 124 tests (97.6%), the main ones were L90M in 28 (22.0%), V82A in 27 (21.2%), M46I in 26 (20.5%), and I54V in 23 (18.1%). The main mutations associated with nucleoside reverse transcriptase inhibitor (NRTI) resistance were M184V in 82 (64.6%), and the thymidine analog mutations were D67N in 51 (40.1%) tests, K70R in 45 (35.4%), T215Y in 40 (31.5%), and M41L in 38 (30.0%). The most frequent major mutations associated with resistance to non-nucleoside RT inhibitors (NNRTI) were K103N in 47 (37.0%), G190A in 11 (8.7%), and G190S in 2 (2.6%) tests. Mutations associated with reduced susceptibility to NRTI and IP simultaneously were observed in 46 (36.2%) tests. The results obtained may contribute to the improvement of the treatment strategies and the management of the antiretroviral drug therapy of HIV-1-infected patients from this Brazilian region, reducing public costs for antiretroviral drugs which have not been efficient in therapy.