Documentation of Subtype C HIV Type 1 Strains in Argentina, Paraguay, and Uruguay

Abstract

HIV subtypes B, F, and BF recombinants have been previously reported in South America. This report describes the presence of HIV-1 subtype C infection in the countries of Argentina, Uruguay, and Paraguay dating back to at least 1999. Surveillance for uncommon non-B/non-F subtype viruses circulating in South America has been conducted in samples obtained from nine countries. Peripheral blood mononuclear cells (PBMC), dried filter paper (FP), and fresh blood (FB) samples were collected from HIV-positive patients from Ecuador, Colombia, Venezuela, Peru, Chile, Bolivia, Argentina, Uruguay, and Paraguay. From a total of 2962 HIV seropositive samples examined during a 9-year period (1995-2003), only 11 (0.4%) were found to be infected with non-B/non-F HIV variants. Eight of these 11 strains were determined to be subtype C by heteroduplex mobility assay (HMA). Five of these 8 strains were further characterized by sequencing and phylogenetic analysis of the protease (Pro) and reverse transcriptase (RT) region of the genome and two were sequenced full length. One of the strains was found to be a unique BC recombinant. The spread of a third subtype of HIV, subtype C, should raise the question of its potential future role in the HIV epidemic in this region.

Heterosexual transmission of human immunodeficiency virus type 1 subtype C in southern Brazil

“…Previous research conducted in Argentina, Uruguay and Paraguay showed only marginal circulation of HIV-1C, with prevalence rates below 1%. [30][31][32][33] Conversely, seven different viral isolates harboring CRF12 BF-derived fragments were found inwards of the border to Uruguay, an observation not previously reported in the region. 10 The identification of this CRF in inland Brazil shows the changing dynamics of the circulation of HIV-1 strains, which warrants periodic molecular surveillance.…”

Molecular screening shows extensive HIV-1 genetic diversity in Central West Brazil

“…The HIV-1 subtype C epidemic in Brazil is concentrated in the South (Rio Grande do Sul State) and its dissemination to other Brazilian States and neighboring countries has been reported Carrion et al, 2004). HIV-1 subtype C was first described in Central Brazil among pregnant women (Stefani et al, 2000).…”

HIV diversity, molecular epidemiology, and the role of recombination

“…Strains seem to segregate according to risk factor; mostly subtype B in men who have sex with men, but many recombinants among heterosexuals and IDUs [39]. Subtype C sequences are beginning to be detected in Argentina, Uruguay, and Paraguay at low levels and also in southern Brazil [40,41].…”