Prevalence of drug transmitted resistance among brazilian HIV-1 infected pregnant women naive to antiretroviral therapy

Abstract

INTRODUCTION: Knowledge about primary resistance profile is the first step to understand HIV-1 infection epidemiology and its evolution. The prevalence rates of drug transmitted resistance (DTR) vary from 7.7 to 15.9%. Several factors can interfere with these rates, among them the time since infection and antiretroviral therapy (ART) availability. This research aims to study DTR among Brazilian HIV-infected pregnant women and the distribution of HIV subtypes. METHODOLOGY: This evaluation is part of a prospective, multicentric and observational cohort study recruiting 37 HIV-infected pregnant women from three different Brazilian States (Minas Gerais, Rio de Janeiro and São Paulo). For this evaluation, blood was collected from HIV-1 infected pregnant women, ART naive, before initiation of ART. The genotyping for resistance testing was done using the Kit ViroSeqTM HIV-1 v2.0. Computer analysis of DTR genetic pattern of protease and reverse transcriptase genes were done based on FASTA Database Files comparing with sequences from the Los Alamos HIV Sequence Database (hiv-web.lanl.gov). For statistical analysis were used the chi-square test, exact Fisher test, and Kruskal-Wallis test for continue variables. RESULTS AND DISCUSSION: Patients (n=37) were mainly afro-descendants (54%). All subjects used zidovudine/lamivudine and lopinavir/ritonavir with effective virological and immunological responses until labor. None of the samples had mutations related to DTR. HIV-1 subtype B was the most frequently found (79%), followed by F (13%) and C (8%). With the exception of a high rate of substance abuse, all other findings corroborate the literature. CONCLUSIONS: Prevalence of HIV-1 DTR remains low in this scenario. Follow-up of this monitoring needs to be continued not only in Brazil, but everywhere, because knowledge of viral mutations will certainly impact on future clinical/obstetrical decisions.