Article

HIV Type 1 Molecular Epidemiology in Cuba: High Genetic Diversity, Frequent Mosaicism, and Recent Expansion of BG Intersubtype Recombinant Forms

Instituto de Medicina Tropical 'Pedro Kourí', La Habana, Cuba.
AIDS Research and Human Retroviruses (Impact Factor: 2.33). 09/2006; 22(8):724-33. DOI: 10.1089/aid.2006.22.724
Source: PubMed

ABSTRACT

Highly diverse HIV-1 genetic forms are circulating in Cuba, including subtypes B and G and two recombinant forms of African origin (CRF18_cpx and CRF19_cpx). Here we phylogenetically analyze pol sequences from a large collection of recent samples from Cuba, corresponding to 425 individuals from all Cuban provinces, which represents approximately 12% of prevalent infections in the country. RNA from plasma was used to amplify a pol segment by reverse transcription-polymerase chain reaction; phylogenetic analyses were performed with neighbour-joining trees and bootscanning. The distribution of genetic forms was subtype B, 41.2%; CRF19_cpx, 18.4%; BG recombinants, 11.6%; CRF18_cpx, 7.1%; subtype C, 6.1%; subtype G, 3.8%; B/CRF18 recombinants, 2.6%; subtype H, 2.1%; B/CRF19 recombinants, 1.7%; and others, 5.4%. Seventy-five (17.6%) viruses were recombinant between genetic forms circulating in Cuba. In logistic regression analyses, adjusting by gender and region, subtype B was more prevalent (OR 5.0, 95% CI 2.0-12.3) and subtype G less prevalent (OR 0.1, 95% CI 0.0-0.5) among men who have sex with men (MSM) than among heterosexuals. Within the main genetic forms of Cuba there were phylogenetic subclusters, several of which correlated with risk exposure or region. BG recombinants formed three phylogenetically related subclusters, corresponding to three different mosaic structures; most of these recombinants were from MSM from Havana City, among whom they have expanded recently, reaching 31% HIV-1 infections diagnosed in 2003. This study confirms the high HIV-1 diversity and frequent recombination in Cuba and reveals the recent expansion of diverse related BG recombinant forms in this country.

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    • "New and novel URFs are highly prevalent, and are markedly evident in Africa,43,48,49 South America,50 Cuba,51 China52,53 and Southeast Asia.25,24,27 They can continue to spread in the population, and lead to the emergence of new CRFs. "
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    ABSTRACT: One of the major characteristics of HIV-1 is its high genetic variability and extensive heterogeneity. This characteristic is due to its molecular traits, which in turn allows it to vary, recombine, and diversify at a high frequency. As such, it generates complex molecular forms, termed recombinants, which evade the human immune system and so survive. There is no sequence constraint to the recombination pattern as it appears to occur at inter-group (between groups M and O), as well as interand intra-subtype within group M. Rapid emergence and active global transmission of HIV-1 recombinants, known as circulating recombinant forms (CRFs) and unique recombinant forms (URFs), requires urgent attention. To date, 55 CRFs have been reported around the world. The first CRF01_AE originated from Central Africa but spread widely in Asia. The most recent CRF; CRF55_01B is a recombinant form of CRF01_AE and subtype B, although its origin is yet to be publicly disclosed. HIV-1 recombination is an ongoing event and plays an indispensable role in HIV epidemics in different regions. Africa, Asia and South America are identified as recombination hot-spots. They are affected by continual emergence and cocirculation of newly emerging CRFs and URFs, which are now responsible for almost 20% of HIV-1 infections worldwide. Better understanding of recombinants is necessary to determine their biological and molecular attributes.
    Full-text · Article · Jun 2013 · Infectious disease reports
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    • "Se omitieron las formas recombinantes (CRF) que son quimeras entre distintos subtipos. son et al., 2005; Pérez et al., 2006; Sierra et al., 2007) además del subtipo B, que circula con una frecuencia de ~40% se han descrito los subtipos G y C, un 20% de CRF18_cpx (forma recombinante entre los subtipos A1, F, G, H, K y U), CRF19_cpx (forma recombinante entre los subtipos A1, D y G), y 3 recombinantes BG (CRFs 20, 23 y 24). A su vez es también uno de los países con la menor prevalencia de infección, debido a una severa y efectiva campaña de prevención de la transmisión (Bayer y Healton, 1989; de Arazoza et al., 2007). "
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    ABSTRACT: Around 3 million people are thought to be infected with human immunodefciency virus (HIV) in the Americas, and around 110000 in Venezuela, where HIV subtype distribution is quite homogenous, with mainly subtype B and few cases of non B subtypes or recombinant forms. The high frequency of subtype B in the Americas is probably due to a founder effect of this viral variant around 1960-1970. The epidemic might have started in Haiti and then was disseminated to other countries. The increase in frequency of non B subtypes in the Americas has been associated to several risk factors: intravenous drug abuse, commercial sex and sanitary and military movilizations. In countries like Cuba, Brasil and countries from the Southern Cone, the presence of non B subtype and recombinant forms is more frequent than in the rest of the region. This situation might mirror what we will fnd in all the Americas in the next decades.
    Full-text · Article · Mar 2009 · Interciencia
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    ABSTRACT: Differences between HIV-1 genetic clades on pathogenicity, transmissibility, and other biological features often have been difficult to prove, due to multiple factors, including large intrasubtype diversity, frequent recombination, and methodological issues. In spite of the difficulties and limitations of the studies, evidence of some associations of HIV-1 clades with biological features has been found
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