Assessing the HIV-1 Epidemic in Brazilian Drug Users: A Molecular Epidemiology Approach

Person who inject illicit substances have an important role in HIV-1 blood and sexual transmission and together with person who uses heavy non-injecting drugs may have less than optimal adherence to anti-retroviral treatment and eventually could transmit resistant HIV variants. Unfortunately, molecular biology data on such key population remain fragmentary in most low and middle-income countries. 

The aim of the present study was to assess HIV infection rates, evaluate HIV-1 genetic diversity, drug resistance, and to identify HIV transmission clusters in heavy drug users (DUs). For this purpose, DUs were recruited in the context of a Respondent-Driven Sampling (RDS) study in different Brazilian cities during 2009. Overall, 2,812 individuals were tested for HIV, and 168 (6%) of them were positive, of which 19 (11.3%) were classified as recent seroconverters, corresponding to an estimated incidence rate of 1.58%/year (95% CI 0.92–2.43%). Neighbor joining phylogenetic trees from env and polregions and bootscan analyses were employed to subtype the virus from132 HIV-1-infected individuals. HIV-1 subtype B was prevalent in most of the cities under analysis, followed by BF recombinants (9%-35%). HIV-1 subtype C was the most prevalent in Curitiba (46%) and Itajaí (86%) and was also detected in Brasília (9%) and Campo Grande (20%). Pure HIV-1F infections were detected in Rio de Janeiro (9%), Recife (6%), Salvador (6%) and Brasília (9%). Clusters of HIV transmission were assessed by Maximum likelihood analyses and were cross-compared with the RDS network structure. Drug resistance mutations were verified in 12.2% of DUs. 

Our findings reinforce the importance of the permanent HIV-1 surveillance in distinct Brazilian cities due to viral resistance and increasing subtype heterogeneity all over Brazil, with relevant implications in terms of treatment monitoring, prophylaxis and vaccine development.

Below:  Map of Brazil showing the frequency of HIV-1 genetic variants across the nine studied cities/State [Recife (PE), Salvador (BA)—Northeast region], [Rio de Janeiro (RJ), Belo Horizonte (MG)—Southeast region], [Itajaí (SC), Curitiba (PR)—South Region], [Campo Grande (MS), Brasilia (DF)—Center West region]. The number of env and pol analyzed samples was depicted in each graphic.

Full article at: http://goo.gl/rhr71z

By:

Monick Lindenmeyer Guimarães, Bianca Cristina Leires Marques, Sylvia Lopes Maia Teixeira, Mariza Gonçalves Morgado

Laboratório de AIDS e Imunologia Molecular, Instituto Oswaldo Cruz- FIOCRUZ, Rio de Janeiro, Brasil

Neilane Bertoni, Francisco Inácio Bastos

Instituto de Comunicação e Informação Científica e Tecnológica em Saúde- FIOCRUZ, Rio de Janeiro, Brasil

  

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