High HIV-1 diversity and moderate prevalence of transmitted drug resistance mutations among antiretroviral-naive HIV-infected pregnant women in Rio de Janeiro, Brazil
Date:
Poster presentation at XXV Brazilian Congress of Virology
Title: High HIV-1 diversity and moderate prevalence of transmitted drug resistance mutations among antiretroviral-naive HIV-infected pregnant women in Rio de Janeiro, Brazil
Authors: Delatorre, Edson, Pilotto, Jose Henrique, & Morgado, Mariza Gonçalves
The increase in the access of antiretroviral (ARV) drugs in Brazil has strong impact in the reduction of morbidity and mortality of HIV-1 positive individuals. However, it may also favors the emergence of HIV-1 drug-resistant variants, due to low genetic barrier of some drugs as well as poor adhesion to treatment regimens, among others. These variants may limit the therapeutic options available for people who were newly infected with them. The aim of this study was to evaluate the viral diversity and prevalence of transmitted drug resistance mutations (TDRM) among ARV-naive HIV-1-infected pregnant women followed at Hospital Geral de Nova Iguaçu (HGNI) in Rio de Janeiro – Brazil, between 2012 and 2013, and to compare the results with a similar previous study including pregnant women recruited from 2005-2008. The viral RNA was extracted and the HIV-1 protease and reverse transcriptase (PR/RT) regions of the pol gene were sequenced from 41 plasma samples using an in house genotyping method. HIV-1 subtypes were determined by phylogenetic analyses and TDRM were detected using the Calibrated Population Resistance Tool-CPR v.6.0. The HIV-1 subtype B was identified in 58.5% of the sequences, representing a decrease in the prevalence found in the previous period (81%). The frequencies of the subtypes F1 (12.2%) and C (2.4%) remained similar, while there was a 3-times increase in the recombinant forms frequency (from 8.0% to 26.8%) since the previous study. The overall prevalence of any HIV-1 TDRM was 12.2%, in accordance to the previous estimates (10.7%). TDRM for nucleoside reverse transcriptase inhibitors remained similar (from 5.6% to 4.9%), while protease inhibitors TDRM increased from 3.0% to 7.3%. No TDRM for nonnucleoside reverse transcriptase inhibitors were identified in the analyzed samples collected between 2012 to 2013, contrasting with the 2%-prevalence previously found. Multidrug-resistant strains were not identified in both periods. These results indicate an increase in the HIV-1 diversity and a probable change in the TDRM profile in Rio de Janeiro between the two periods. The moderate prevalence of HIV-1 TDRM in this population could affect the virological outcome of the standard first-line ARV regimens to prevent HIV vertical transmission, reinforcing the importance of continuous monitoring of the HIV-1 genetic diversity and TDRM in Brazil.
