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Temporal dynamics of HIV-1 circulating subtypes in distinct exposure categories in southern Brazil

Sabrina EM Almeida1*, Rubia M de Medeiros13, Dennis M Junqueira13, Tiago Gräf14, Caroline PB Passaes2, Gonzalo Bello2, Mariza G Morgado2 and Monick L Guimarães2

Author Affiliations

1 Centro de Desenvolvimento Técnico e Científico – CDCT, Fundação Estadual de Produção e Pesquisa em Saúde – FEPPS, Av. Ipiranga, 5400, 3° andar, CEP: 90610-000, Porto Alegre, RS, Brazil

2 Laboratório de AIDS & Imunologia Molecular. Instituto Oswaldo Cruz – FIOCRUZ. Av. Brasil 4365, 439 - Pavilhão Leonidas Deane, sala 413, CEP: 21040-900, Rio de Janeiro, RJ, Brazil

3 Programa de Pós-graduação em Genética e Biologia Molecular, Departamento de Genética, Centro de Ciências Biológicas, Universidade Federal do Rio Grande do Sul (UFRGS), 9500 - Prédio 43323M, CEP:91501-970, Porto Alegre, RS, Brazil

4 Programa de Pós-graduação em Biotecnologia e Biociências, Departamento de Microbiologia, Imunologia e Parasitologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina (UFSC), Campus Universitário, CEP: 88040-970, Florianópolis, SC, Brazil

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Virology Journal 2012, 9:306  doi:10.1186/1743-422X-9-306

Published: 12 December 2012



The HIV-1 epidemic in Brazil is predominantly driven by subtype B. However, in Brazilian Southern region subtype C prevails and a relatively high AIDS incidence rate is observed. The aim of the present study was to assess the temporal dynamics of HIV-1 subtypes circulating in patients from distinct exposure categories in Southern Brazil. For this purpose 166 HIV-1 samples collected at the years of 1998 (group I) and 2005–2008 (group II) were analyzed.


Analysis of group I revealed statistically significant (p < 0.05) associations between MSM and subtype B as well as between IDU and subtype C; while no statistical significant association between HIV-1 subtypes and exposure category was verified for group II. An overall temporal increase in the prevalence of subtype C and BC recombinants was observed in both HET and MSM populations, accompanied by a proportional decrease in the prevalence of the pure subtype B.


The present study shows an association between HIV subtypes and exposure categories at the middle 1990s in Southern Brazil. Our findings suggest that MSM and IDU populations might have played a major role in the introduction and initial dissemination of subtypes B and C, respectively, in Southern Brazil. This study also suggests a trend towards homogenization of HIV-1 strains across distinct exposure categories as a consequence of an overall increase in the prevalence of subtype C and BC recombinants in both HET and MSM populations.

HIV-1; Brazil; Subtypes; Exposure categories; Temporal dynamics