Frequency distribution of HCV resistance-associated variants in infected patients treated with direct-acting antivirals.

Background: Hepatitis C virus (HCV) is a global public health problem. Second-generation direct-acting antivirals targeting non-structural regions on the viral genome are the cornerstone for treatment of chronic infection. However, resistance-associated variants (RAVs) have been reported to be associated with therapeutic failure.

Brazilian network for HIV Drug Resistance Surveillance (HIV-BresNet): a survey of treatment-naive individuals.

Introduction: In Brazil, more than 487,450 individuals are currently undergoing antiretroviral treatment. In order to monitor the transmission of drug-resistant strains and HIV subtype distribution in the country, this work aimed to estimate its prevalence and to characterize the nationwide pretreatment drug resistance in individuals recently diagnosed with HIV between 2013 and 2015.

Methods: The HIV threshold survey methodology (HIV-THS, WHO) targeting antiretroviral-naive individuals with recent HIV diagnosis was utilized, and subjects were selected from 51 highly populated cities in all five Brazilian macroregions.

Prevalence of resistance-associated mutations in human immunodeficiency virus type 1-positive individuals failing HAART in Rio de Janeiro, Brazil.

We investigated the occurrence of HIV-1 antiretroviral resistance in individuals failing to respond to highly active antiretroviral therapy (HAART) attended by RENAGENO from 2001-2004. One hundred and seventeen patients were selected for this study; their plasma viral RNA was extracted and the PR and RT genes sequenced to examine subtype, genetic polymorphisms and mutations associated with resistance to antiretroviral drugs. HIV-1 sequence analysis showed that 86/100 (86%) were infected with subtype B, 7/100 (7%) with subtype F and 7/100 (7%) with RT/PR hybrid forms (2 D/B, 2 F/B, 2 B/F and 1 D/F).

Human immunodeficiency virus type 1 protease and reverse transcriptase mutation patterns among treatment-naive patients in different stages of infection in Rio de Janeiro, Brazil.

The presence of genetic mutations in HIV-1-positive untreated individuals and its contribution to treatment failure, either in an individual or on a population basis, remains an important concern. The goal was to analyze and compare HIV-1 reverse transcriptase (RT) and protease (PR) genes of untreated individuals with chronic and recent infections. Fifty-one chronic infected individuals for whom initiation of antiretroviral treatment had been recommended and 20 individuals with recent documented HIV-1 seroconversion had their plasma viral RNA extracted and the PR and RT genes sequenced in order to determine subtype, presence of genetic polymorphisms and mutations associated with resistance to antiretroviral drugs.

Prevalence of mutations related to HIV-1 antiretroviral resistance in Brazilian patients failing HAART.

Background: Current guidelines for antiretroviral (ARV) therapy recommend at least triple-drug combination, the so-called highly active antiretroviral therapy (HAART). Not all patients respond to HAART and the development of drug resistance remains one of the most serious obstacles to sustained suppression of HIV.

Objective: In an attempt to correlate the HIV therapeutic failure with reverse transcriptase (RT) and protease resistance mutations, we describe the ARV resistance profile in patients failing HAART in Brazil.