Frequency of subtype B and F1 dual infection in HIV-1 positive, Brazilian men who have sex with men

Introdução: Como varios estudos sobre vacinacao contra HIV estao em progresso, e importante compreender a frequencia na qual ocorrem co/superinfeccoes intra ou intersubtipos em grupos de alto risco. Esse conhecimento auxiliaria no desenvolvimento de programas de prevencao futuros. Nesse estudo transversal, relatamos a frequencia de coinfeccao entre os subtipos B e F1 em uma cohorte clinica de 41 homens que fazem sexo com homens (HSH), recem infectados com HIV-1, em São Paulo, Brasil. Metodologia: O DNA proviral do HIV-1 foi isolado a partir de leucocitos de sangue periferico de sujeitos polimorfonucleares (PMNs), que foram obtidos no momento da inscricao. Cada individuo era conhecidamente infectado por um virus do subtipo B, conforme determinado em estudo anterior. Um pequeno fragmento do gene da integrase (nucleotideo 4255-4478 do HXB2) foi amplificado por PCR utilizando primers especificos para F1. Os resultados da PCR foram confirmados por analise filogenetica. Os dados de carga viral (VL) foram inferidos a partir dos prontuarios de cada paciente. Resultados: Das 41 amostras estudadas, 5 apresentaram DNA proviral do subtipo F1, O que representa uma taxa de 12,2% de coinfeccao. A comparacao entre os valores de carga viral entre os coinfectados e os infectados apenas pelo subtipo B nao foi estatisticamente diferente (p> 0,16). Nos individuos com infeccao dupla a carga viral mediana foi de 5,3 x 104 copias/mL (intervalo de <400 u 12,5 x 104 copias/mL), e nos individuos infectados apenas pelo subtipo B a carga viral mediana foi de 4,3 x 104 copias/mL (intervalo de <400 u 39,9 x 104 copias/mL). Conclusao: Esse estudo indicou que a coinfeccao entre os subtipos B e F1 ocorre com frequencia na populacao de homens que fazem sexo com homens, HIV-1 positivos, como sugerido por um grande numero de virus recombinantes BF1 relatados no Brasil. Na ausencia de uma vacina eficaz contra o HIV-1, o teste para co/superinfeccao e a implantacao de medidas eficazes nos grupos de risco podem ajudar a reduzir a exposicao viral, a transmissao e a recombinacaoBV UNIFESP: Teses e dissertaçõe

Characterization of Partial and Near Full-Length Genomes of HIV-1 Strains Sampled from Recently Infected Individuals in São Paulo, Brazil

Background: Genetic variability is a major feature of human immunodeficiency virus type 1 (HIV-1) and is considered the key factor frustrating efforts to halt the HIV epidemic. A proper understanding of HIV-1 genomic diversity is a fundamental prerequisite for proper epidemiology, genetic diagnosis, and successful drugs and vaccines design. Here, we report on the partial and near full-length genomic (NFLG) variability of HIV-1 isolates from a well-characterized cohort of recently infected patients in Sao Paul, Brazil.Methodology: HIV-1 proviral DNA was extracted from the peripheral blood mononuclear cells of 113 participants. the NFLG and partial fragments were determined by overlapping nested PCR and direct sequencing. the data were phylogenetically analyzed.Results: of the 113 samples (90.3% male; median age 31 years; 79.6% homosexual men) studied, 77 (68.1%) NFLGs and 32 (29.3%) partial fragments were successfully subtyped. of the successfully subtyped sequences, 88 (80.7%) were subtype B sequences, 12 (11%) BF1 recombinants, 3 (2.8%) subtype C sequences, 2 (1.8%) BC recombinants and subclade F1 each, 1 (0.9%) CRF02 AG, and 1 (0.9%) CRF31 BC. Primary drug resistance mutations were observed in 14/101 (13.9%) of samples, with 5.9% being resistant to protease inhibitors and nucleoside reverse transcriptase inhibitors (NRTI) and 4.9% resistant to non-NRTIs. Predictions of viral tropism were determined for 86 individuals. X4 or X4 dual or mixed-tropic viruses (X4/DM) were seen in 26 (30.2%) of subjects. the proportion of X4 viruses in homosexuals was detected in 19/69 (27.5%).Conclusions: Our results confirm the existence of various HIV-1 subtypes circulating in São Paulo, and indicate that subtype B account for the majority of infections. Antiretroviral (ARV) drug resistance is relatively common among recently infected patients. the proportion of X4 viruses in homosexuals was significantly higher than the proportion seen in other study populations.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ São Paulo, Fac Med, Div Clin Immunol & Allergy, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Translat Med, São Paulo, BrazilFundacao Pro Sangue, Blood Ctr Sau Paulo, São Paulo, BrazilUniv São Paulo, Dept Infect Dis, São Paulo, BrazilPubl Hlth Dept São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, Dept Translat Med, São Paulo, BrazilFAPESP: 04/15856-9FAPESP: 2006/50096-0Web of Scienc

Establishment of the serologic testing algorithm for recent human immunodeficiency virus (HIV) seroconversion (STARHS) strategy in the city of São Paulo, Brazil

Several strategies aim at characterizing the AIDS epidemic in different parts of the world. Among these, the identification of recent HIV-1 infections using the recently described serologic testing algorithm for recent human immunodeficiency virus (HIV) seroconversion (STARHS) strategy was employed in four testing sites of the City of São Paulo Public Health Department (CSPPHD). Those identified as recently infected were invited to participate in a prospective clinical and laboratory evaluation study. We describe the establishment of the patient identification network and the success in enrolling the participants, as well as their clinical and laboratory characteristics. From May to December 2002, 6,443 persons were tested for HIV in the four participating sites, of whom 384 (5.96%) tested HIV-1 positive; 43 (11.2%) of them were identified as recently infected. Twenty-two were successfully enrolled in the follow-up study, but three of them did not meet clinical and/or laboratory criteria for recent HIV-1 infection. After these exclusions, the laboratory findings revealed a median CD4+ T lymphocyte count of 585 cells/muL (inter-quartile range 25-75% [IQR], 372-754), a CD8+ T lymphocyte count of 886 cells/muL (IQR, 553-1098), a viral load of 11,000 HIV-RNA copies/mL (IQR, 3,650-78,150), log10 of 4.04 (IQR 3.56-4.88). The identification of recent HIV infections is an extremely valuable way to evaluate the spread of the virus in a given population, especially when cohort studies, considered the gold standard method to evaluate incidence, are not available. This work demonstrated that establishing a network to identify such patients is a feasible task, even considering the difficulties in a large, resource-limited country or city

HIV-1 strain subtyping by partial sequences.

<p>HIV-1 strain subtyping by partial sequences.</p

Maximum likelihood tree of sequences identified in this study (indicated by black circles) and reference strains inferred from full-length <i>gagpol</i> (A) and <i>env</i> (B) nucleotide sequences.

<p>For clarity purposes, the tree was midpoint rooted. The approximate likelihood ratio test (aLRT) values of≥90% are indicated at nodes. The scale bar represents 0.05 nucleotide substitutions per site.</p

Phylogenetic relationships among subtype B HIV-1 NFLG sequences sampled from different countries.

<p>(a) Midpoint-rooted maximum-likelihood tree of 435 HIV-1 non recombinant subtype B NFLG sequences sampled from various global locations (colored branch). In addtion to previously published Brazilian subtype B NFLGs and other South American sequences from neighboring countries. The tree also contains 62 isolates sampled in São Paulo from HIV-1 recently infected patients over a 4- year period between 2002–2006 (the present datasets). (b) For clarity, the Brazilian isolates branched as a monophyletic cluster was displayed. Annotation of samples is as follows: symbol-brown square-F indicates heterosexual female, and symbol-black square indicates homosexual male. The approximate likelihood ratio test (aLRT) values of≥70% are indicated. The scale bar represents 0.01 nucleotide substitutions per site.</p

Characteristics and main findings of the Brazilian HIV-1 recently infected individuals.

<p>Characteristics and main findings of the Brazilian HIV-1 recently infected individuals.</p

Schematic representation of the NFLG structure and breakpoint profiles of the BF1 sequences identified in this study and other BF1 URF and CRF published sequences.

<p>Sequences marked with the symbol (*) were originally classified as pure subtype but were characterized in the current analysis as pure B subtype, thus suggesting that a revised classification of these isolates in the GenBank and the HIV databases is appropriate. The region of subclade F1 and subtypes B are indicated at the bottom.</p

Drug-resistance mutations detected in antiretroviral (ARV) naïve patients.

<p>*HET ^M; heterosexual man, MSM; men who have sex with men.</p