Rosângela Rodrigues

High-resolution phylogenetics and phylogeography of human immunodeficiency virus type 1 subtype C epidemic in South America.

Human immunodeficiency virus type 1 subtype C (HIV-1C) represents 30-65% of HIV infections in southern Brazil, and isolated cases of HIV-1C infection have also been reported in Argentina, Uruguay, Paraguay and Venezuela. Phylogenetic studies have suggested that the Brazilian subtype C epidemic was initiated by the introduction of closely related strains. Nevertheless, because of sampling limitations, the point of entry and the timing of subtype C introduction into Brazil, as well as the origin of the founder lineage, remain controversial. The present study investigated the origin, spread and phylogeography of HIV-1C in South America. Phylogenetic analysis showed a well-supported monophyletic clade including all available strains from Brazil, Uruguay and Argentina. Only one lineage from Venezuela was unrelated to the epidemic involving the other three countries. Molecular clock and likelihood mapping analysis showed that HIV-1C introduction in Brazil dated back to the period 1960-1970, much earlier than previously thought, and was followed by a nearly simultaneous star-like outburst of viral lineages, indicating a subsequent rapid spread. Phylogeographic patterns suggested Paraná or Rio Grande do Sul as the possible entrance points of subtype C and an asymmetrical gene flow from Paraná to Sao Paulo, Santa Catarina and Rio Grande do Sul, as well as from Rio Grande do Sul to Sao Paulo fostered by the strong inter-connectivity between population centres in southern Brazil. The study illustrates how coupling phylogeography inference with geographical information system data is critical to understand the origin and dissemination of viral pathogens and potentially predict their future spread.

High prevalence and association of HIV-1 non-B subtype with specific sexual transmission risk among antiretroviral naïve patients in Porto Alegre, RS, Brazil

In South Brazil the circulation of two HIV-1 subtypes with different characteristics represents an important scenario for the study of the impact of HIV-1 diversity on the evolution of the HIV-1 epidemic and AIDS disease. HIV-1 B, the predominant variant in industrialized countries and HIV-1 C, the most prevalent subtype in areas with rapid epidemic growth, are implicated in most infections. We evaluated blood samples from 128 antiretroviral (ARV) naïve patients recruited at entry to the largest HIV outpatient service in Porto Alegre. Based on partial pol region sequencing, HIV-1 C was observed in 29%, HIV-1 B in 22.6% and, the recently identified CRF31_BC, in 23.4% of 128 volunteers. Other variants were HIV-1 F in 10% and other mosaics in 5.5%. In order to evaluate the association of socio-behavioral characteristics and HIV-1 subtypes, interviews and laboratory evaluation were performed at entry. Our data suggest an established epidemic of the three major variants, without any evidence of partitioning in either of the subgroups analyzed. However, anal sex practices were associated with subtype B, which could indicate a greater transmissibility of non-B variants by vaginal intercourse. This study provides baseline information for epidemiologic surveillance of the changes of the molecular characteristics of HIV-1 epidemics in this region.

Diversity and prevalence of antiretroviral genotypic resistance mutations among HIV-1-infected children

OBJECTIVE To evaluate genotyping and subtyping in antiretroviral (ARV) naïve and experienced children, as well as drug resistance profiles through genotyping in these children. METHODS This retrospective study assessed ARV-naïve HIV children and HIV children failing highly active antiretroviral treatment (HAART) followed up at Santa Casa de São Paulo. Genotyping was performed using purified polymerase chain reaction (PCR) products from retrotranscribed RNA using Kit Viroseq HIV-1 Genotyping System 2.0 or nested PCR in-house. Sequencing was performed using automatic equipment (ABI 3100). ARV resistance mutations were analyzed in the Stanford HIV Drug Resistance Database and subtyping was performed at the National Center for Biotechnology Information (NCBI), using SimPlot analysis, together with phylogenetic analysis. RESULTS No primary ARV resistance mutation was detected in the 24 ARV-naïve children, although there were mutations that may contribute to resistance to nucleoside analogue reverse transcriptase inhibitors (NRTI) (12.5%) and to protease inhibitors (PI) (95.8%). For the 23 children failing HAART, we found ARV resistance mutations to NRTI in 95.6% and to non-nucleoside analogue reverse transcriptase inhibitors (NNRTI) in 60.8%. For PI, we found ARV resistance mutations in 95.7%, 47.8% of which had only polymorfisms. In the subtyping analyses, 78.3% of the sequences clustered in HIV-1 subtype B, 4.3% in C, 13% in F and 4.4% in recombinant forms. CONCLUSION Our results show low rates of primary resistance in ARV-naïve children and high rates of resistance in children failing ARV treatment, which is compatible with ARV use in these patients.

Rate and incidence estimates of recent human immunodeficiency virus type 1 infections among pregnant women in São Paulo, Brazil, from 1991 to 2002

ABSTRACT The serological testing algorithm for recent human immunodeficiency virus (HIV) seroconversion (STARHS) was employed to estimate HIV incidence among pregnant women from São Paulo, Brazil. A cross-sectional study (1999 to 2002) showed an incidence of infection of 0.2 per 100 pregnant women per year (95% confidence interval, 0.041 to 0.608). Western blot profiles suggested an association between results of the STARHS analysis and gp41/gp31 bands.

HIV genotyping among female sex workers in the State of Santa Catarina

The objective of this study was to investigate the frequency of HIV infection among female sex workers in the port area of Imbituba (State of Santa Catarina), and to identify the viral subtype and its susceptibility to antiretroviral medications. Ninety women were interviewed between December 2003 and February 2004. Six (6.7%) were HIV-positive. Genotyping for HIV, performed on four samples, detected subtype C in three of them, which is predominant in Africa and Asia, and subtype B in one of them, which is prevalent in Brazil, USA and Europe. The results suggest that the Port of Imbituba may be one of the gateways for HIV-1 subtype C to enter Brazil, and for its dissemination to the rest of the country and the Mercosul area, along the highway BR-101. This points towards the need for preventive work to reduce the introduction and dissemination of HIV subtype C in Brazil.

Genetic diversity and primary resistance among HIV-1-positive patients from Maringá, Paraná, Brazil

The objective of this study is to identify subtypes of Human Immunodeficiency Virus type 1 (HIV-1) and to analyze the presence of mutations associated to antiretroviral resistance in the protease (PR) and reverse transcriptase (RT) regions from 48 HIV-1 positive treatment naïve patients from an outpatient clinic in Maringá, Paraná, Brazil. Sequencing was conducted using PR, partial RT and group-specific antigen gene (gag) nested PCR products from retrotranscribed RNA. Transmitted resistance was determined according to the Surveillance Drug Resistance Mutation List (SDRM) algorithm. Phylogenetic and SimPlot analysis of concatenated genetic segments classified sequences as subtype B 19/48 (39.6%), subtype C 12/48 (25%), subtype F 4/48 (8.3%), with 13/48 (27.1%) recombinant forms. Most recombinant forms were B mosaics (B/F 12.5%, B/C 10.4%), with one C/F (2.1%) and one complex B/C/F mosaic (2.1%). Low levels of transmitted resistance were found in this study, 2/48 (2.1% to NRTIs and 2.1% for PI). This preliminary data may subsidize the monitoring of the HIV evolution in the region.

Bioinformatics tools for HIV-1 identification in southern brazilian states

HIV/AIDS pandemic affected 39.4 million people at the end of 2004, spreading at the rate of 15.000 new infections per day [1]. Although Brazil ranks in fourth in number of reported AIDS cases, limited information concerning the molecular diversity of HIV-1 circulating subtypes is known [3]. Southern Brazil has a particular HIV-1 epidemic, whereas subtype B dominates other regions of the country and subtype C reported cases are rare, in southern states the subtypes C and B have equivalent proportions, and the subtype C seems to be growing up since it was first described in Porto Alegre city, capital of Rio Grande do Sul (RS), at 90s.