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

Abstract

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 pol regions 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.

Potential overestimation of HIV-1 sub-subtype F1 circulation in Rio de Janeiro, Brazil

“…Seventy-three HIV-1 sub-subtype F1 isolates were identified in previous HIV-1 molecular epidemiological studies carried out at the Laboratory of AIDS and Molecular Immunology of Oswaldo Cruz Institute/FIOCRUZ. Included in these previous studies were 635 individuals from Rio de Janeiro, Brazil, from whom biological samples were collected between 1998 and 2013 and were screened using the C2V3 envelope region ( Teixeira et al 2004 , Guimarães et al 2010 , Pimentel et al 2013 , Guimarães et al 2015 , Leite et al 2017 ). From those 73 samples, biological material was still available for only 55 individuals; these samples were used in the present study.…”

HIV-1 infection among crack cocaine users in a region far from the epicenter of the HIV epidemic in Brazil: Prevalence and molecular characteristics

“…Possible transmission clusters of subtype B clade were investigated constructing phylogenetic trees with four different datasets. Phylogenetic analyses were performed using 199 subtype B sequences from the same endemic region ( S1 Fig ), BLAST selected sequences including 52 subtype B sequences with high similarity (above 95%) ( S2 Fig ), a third dataset including 40 subtype B sequences retrieved from the Genbank which were collected among 10 Brazilian intravenous drug users [ 17 ] and 30 from prisoners collected in the same geographical region [ 18 ] ( S3 Fig ). The fourth data set included 95 BLAST selected isolates with high similarity (above 95%) with subtype B, C, F1 and BF from our study ( S4 Fig ).…”

“…HIV-1 subtype C has rarely been found among drug users outside the southern region. However, in a recent publication [ 17 ] about a survey of HIV-1 among drug users from eight Brazilian cities outside the southern region, subtype C was identified only in Campo Grande and Brasilia, both cities in the central-west region.…”

Cross-Neutralizing Antibodies in HIV-1 Individuals Infected by Subtypes B, F1, C or the B/Bbr Variant in Relation to the Genetics and Biochemical Characteristics of the env Gene

“…In Brazil, HIV-1 subtypes B, their B/Bbr variants, F1 and C, as well as diverse recombinants evolving these subtypes are prevalent [18,19]. The B/Bbr variant, which represents 37 to 57% of HIV-1 subtype B strains in the country, differs from the pandemic subtype B by the substitution of the amino acid proline by a tryptophan at the top of the V3 loop of gp120 (GWGR instead of the classical GPGR) [18,20–22] and its antigenic characteristics [20,23,24].…”