Abstract

Antiretroviral drug resistance in men who have sex with men in Brazil

E.H. Bermudez Aza¹, L.R. Kerr², A.A. Pinho³, M.B. Mello⁴, A.M. de Brito⁵, M.I.C. Dourado⁶, M.D. Guimarães⁷, A.S. Benzaken⁸, L.C. de Oliveira⁹, A.S. Moraes¹⁰, S. Batista¹¹, E.M. Hamann¹², G. Freitas¹³, F. Abreu¹⁴, C. Kendall¹⁵, G.W. Rutherford¹⁶, W. McFarland¹⁶, E.C. Sabino<sup>17

1</sup>Universidade Federal de São Paulo, Infectious Diseases, Sao Paulo, Brazil, ²Federal University of Ceará, Fortaleza, Brazil, Fortaleza, Brazil, ³Fiocruz ICICT, Rio de Janeiro, Brazil, ⁴ICICT, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil, ⁵Fiocruz Centro de Pesquisas Aggeu Magalhães, Recife, Brazil, ⁶Federal University of Bahia, Salvador, Brazil, ⁷Federal University of Minas Gerais, Belo Horizonte, Belo Horizonte, Brazil, ⁸Fundação Alfredo da Matta, Manaus, Brazil, ⁹Secretaria de Saúde de Curitiba, Curitiba, Brazil, ¹⁰Secretaria de Saúde de Itajaí, Itajaí, Brazil, ¹¹Federal University of Rio de Janeiro, Rio de Janeiro, Brazil, ¹²Brasilia University, Brasilia, Brazil, ¹³Secretaria de Saúde de Campo Grande, Campo Grande, Brazil, ¹⁴Secretaria de Saúde de Santos, Santos, Brazil, ¹⁵Tulane University School of Public Health and Tropical Medicine, New Orleans, United States, ¹⁶University of California at San Francisco, San Francisco, United States, ¹⁷University of São Paulo, São Paulo, Brazil

Background: There are few studies of HIV subtypes and drug resistance in some well-characterized populations in Brazil. This study analyzed HIV diversity among men who have sex with men (MSM) in the five geographic regions of Brazil.
Methods: Using Respondent Driven Sampling (RDS) 3.859 MSM were interviewed in 10 cities around the country. Of these, 316 (8.2%) were positive for HIV and 186 agreed to provide samples for genotype testing. We describe the preliminary results from samples of 162 subjects collected in seven of the most populated cities in Brazil: Rio de Janeiro, Belo Horizonte, Recife, Manaus, Campo Grande and Itajaí. Sixty-one (37.7%) subjects were antiretroviral therapy (ART) experienced (AE) and 101 ART-naïve (AN). The reverse transcriptase and protease regions of the virus were sequenced and analyzed for drug resistant mutations according to WHO guidelines
Results: According to subtypes, the classification was as follows: subtype B: 80.3%, C: 10.5% , F: 4.9% and Recombinant : 4.3%. Rates of resistance in ART naïve and ART exposed were 17,5% and 42% in each case, 13 isolates (8.1%) showed antiretroviral mutations (ARM) related to resistance to protease inhibitors, 35 (21.7%) to nucleoside reverse transcriptase inhibitors (NRTIs) and 23 (14.2%) to non-nucleoside reverse transcriptase inhibitors (NNRTIs), respectively. The most common NRTIs ARM was M184V (21 cases) and the most common NNRTIs ARM was K103N (16 cases).
Conclusions: Our preliminary data suggest a high level of transmitted resistance in the drug naive group. Patients from this group or those whose partners are already on ART may benefit from pre-treatment genotypic testing to optimize the choice of treatment. Additional data using larger samples with more systematic and national ART resistance surveillance is needed in Brazil to better define risk factors associated with transmission of resistant HIV in MSM.