Antiretroviral drug resistance and phylogenetic diversity of HIV‐1 in Chile

Abstract

This study reports the analysis of human immunodeficiency virus type 1 (HIV-1) protease (PR) and reverse transcriptase (RT) coding sequences from 136 HIV-1-infected subjects from Chile, 66 (49%) of them under antiretroviral (ARV) treatment. The prevalence of mutations conferring high or intermediate resistance levels to ARVs was 77% among treated patients and 2.5% among drug-naïve subjects. The distribution of resistance prevalence in treated patients by drug class was 61% to nucleoside RT inhibitors, 84% to nonnucleoside RT inhibitors, and 46% to PR inhibitors. Phylogenetic analysis revealed that 115 (85%) subjects were infected with subtype B viruses, 1 with a subtype F1 virus, and 20 (15%) carried BF intersubtype recombinants. Most BF recombinants grouped into two clusters, one related to CRF12_BF, while the other could represent a new circulating recombinant form (CRF). In conclusion, this is the first report analysing the prevalence of ARV resistance which includes patients under HAART from Chile. Additionally, phylogenetic analysis of the PR-RT coding sequences reveals the presence of BF intersubtype recombinants.

Prevalence of antiretroviral drug resistance among treatment-naive and treated HIV-infected patients in Venezuela

“…The prevalence of mutations conferring resistance to ARV drugs found in treated patients was similar to those described recently in Chile for PIs and NRTIs (46% and 61%, respectively) and similar to the prevalence reported in Rio de Janeiro, Brazil (70% to NRTIs, 55% to NNRTIs and 45% to PIs) (Bongertz et al 2007, Rios et al 2007). This prevalence was also higher than that reported for Venezuela earlier this decade by Delgado et al (2001).…”

“…This prevalence was also higher than that reported for Venezuela earlier this decade by Delgado et al (2001). However, resistance to NNRTIs was significantly higher in Chile (84%) (Rios et al 2007). The same prevalence of resistance to PIs and NRTIs has been reported in a large study from the USA (41% and 71%, respectively), whereas the prevalence of resistance to NNRTIs was significantly lower (25%) (Richman et …”

The prevalence of resistance-associated mutations to protease and reverse transcriptase inhibitors in treatment-naïve (HIV1)-infected individuals in Casablanca, Morocco

“…The problem of widespread dissemination becomes even more serious when the resistance to two or more classes of drugs can also be transmitted in primary infection and shorten the time to first virological failure [6,7,11,14]. Some studies report very different rates of transmission of drug resistant viruses, ranging from 20% in North America [6,[15][16][17], to 10% or less in Europe and Latin America [8,[18][19][20][21][22][23][24][25].…”

“…However, an undesired consequence of antiretroviral therapy has been the selection and emergence of drug-resistant virus variants which are a major obstacle that limits the long-term efficacy of a successful treatment with currently available antiretroviral drugs (ARVs) [4][5][6][7]. Thus, drug resistance is now a widespread and growing problem that not only involves antiretroviral-treated patients, but also drug-naïve individuals infected with HIVresistant strains [8].…”

Drug Resistance Mutation Profile and Accumulation Kinetics in Human Immunodeficiency Virus-Positive Individuals Infected with Subtypes B and F Failing Highly Active Antiretroviral Therapy Are Influenced by Different Viral Codon Usage Patterns

“…Subtype C isolates are prevalent in southern states, with a relatively high proportion (30 to 60%), accounting for the main non-B isolate in this region. In summary, subtype F and its mosaic forms and CRFs are the major non-B strains circulating in Brazil (3,4,5,10,30) and South America (7,12,19,29), accounting for approximately 10 to 20% of non-B virus infections for this continent.…”