High prevalence and association of HIV-1 non-B subtype with specific sexual transmission risk among antiretroviral naïve patients in Porto Alegre, RS, Brazil Alta prevalência e associação do subtipo não-B do vírus HIV-1 com risco específico de transmissão sexual entre pacientes virgens de tratamento antirretroviral em Porto Alegre, Brasil

• Published in: Revista do Instituto de Medicina Tropical de São Paulo
• Main Authors: Cláudia Fontoura Dias, Cynara Carvalho Nunes, Isabela Osório Freitas, Isabel Saraiva Lamego, Ilda Maria Rodrigues de Oliveira, Sabrina Gilli, Rosângela Rodrigues, Luis Fernando Brigido
• Format: Article in Journal/Newspaper
• Language: English
• Published: Universidade de São Paulo (USP) 2009
• Subjects: HIV-1 subtypes; HIV-1 CRF31_BC; Molecular epidemiology; Risk factors; Brazil; Arctic medicine. Tropical medicine; RC955-962; Infectious and parasitic diseases; RC109-216; Alta; Arctic
• Online Access: https://doi.org/10.1590/S0036-46652009000400003; https://doaj.org/article/ef60f54ad09f436fbf90b847daa82017

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. No sul do Brasil a circulação de dois subtipos de HIV-1 com características diferentes representa importante cenário para o estudo do impacto da diversidade do HIV-1 na evolução da epidemia e na AIDS. O HIV-1 B, variante predominante nos países industrializados e o HIV-1 C, o subtipo mais prevalente em áreas com maiores taxas de crescimento da epidemia, estão implicados na maioria das infecções. Avaliamos amostras de sangue de 128 pacientes sem exposição a antirretrovirais, recrutados ao ingressarem no maior serviço ambulatorial de HIV/AIDS de Porto Alegre. Com base no sequenciamento parcial da região pol, o HIV-1 C foi observado em 29%, HIV-1 B em 22,6% e uma forma recombinante ...