Major drug resistance mutations to HIV-1 protease inhibitors (PI) among patients exposed to PI class failing antiretroviral therapy in São Paulo State, Brazil.

Background: Protease inhibitors (PI) are especially important in salvage therapy. Previous treatment failure with a PI containing regimen may elicit resistance mutations, reducing PI susceptibility and limiting treatment options. The aim of this study was to describe major PI mutations among patients exposed to at least one PI to evaluate predictors of mutation emergence and the impact of subtypes on resistance.

Prevalence of HIV-1 transmitted drug resistance and viral suppression among recently diagnosed adults in São Paulo, Brazil.

HIV-1 transmitted drug resistance (TDR) mutations may reduce the efficacy of antiretroviral therapy (ART), but pre-treatment testing to determine the virus genotype can improve the efficacy of ART. Unfortunately, issues related to cost and logistics of pre-treatment testing limit its use in resource-limited settings. We studied 596 ART-naive individuals who were newly diagnosed from 2014 to 2016 in São Paulo, Brazil, to evaluate TDR and virological outcome after 48 weeks of genotype-guided therapy.