Molecular Epidemiology of HIV Type 1 in Ecuador, Peru, Bolivia, Uruguay, and Argentina

Abstract

Surveillance for HIV infection among people at increased risk was conducted in five countries in South America. Seroprevalence studies were conducted in more than 36,000 people in Ecuador, Peru, Boliva, Uruguay, and Argentina, along with genetic analysis of the HIV-1 strains. In all countries, the prevalence of HIV-1 among men who have sex with men (MSM) was high (3-30%), whereas the prevalence among female commercial sex workers (FCSMs) was low (0.3-6%). By envelope heteroduplex mobility assay, subtype B predominated in MSM communities and in FCSWs in Ecuador, Bolivia, and Peru. A new genetic screening assay, the multiregion hybridization assay for subtypes B and F (MHA-bf), was developed to improve large-scale genetic screening in South America. MHA-bf can screen four regions of the genome for subtype B or subtype F, and thus can detect most recombinants. The sensitivity of MHA-bf when applied to a panel of pure subtypes and CRF12_BF was 100%, and 88% of unique recombinants were also detected as recombinant. Using MHA-bf, more than 80% of samples from Ecuador, Peru, and Bolivia were classified as pure subtype B, whereas in Uruguay and Argentina this proportion was only 30 to 40%. BF recombinants were the most prevalent form of HIV-1 in Uruguay and Argentina. Subtype B is the most common subtype in countries lacking injecting drug use (IDU) epidemics, whereas BF recombinants are more common in countries where extensive IDU epidemics have been documented, suggesting the ontogeny of recombinant strains in particular risk groups in South America.

Biologic and Genetic Characterization of a Panel of 60 Human Immunodeficiency Virus Type 1 Isolates, Representing Clades A, B, C, D, CRF01_AE, and CRF02_AG, for the Development and Assessment of Candidate Vaccines

“…Each strain was characterized by sequencing of the complete genome, except for a small portion of the long terminal repeat. Thirty-nine viruses were sequenced previously (2,11,12,19,(21)(22)(23)(24)60). Twenty-one new complete genome sequences were generated for this study.…”

Novel Multiregion Hybridization Assay for the Identification of the Most Prevalent Genetic Forms of the Human Immunodeficiency Virus Type 1 Circulating in Portugal

“…MHA are particularly useful to describe complex epidemics since they can be designed to account for the viral genetic diversity in specific areas of the globe. [9][10][11][12][13][14][15][16][17] Furthermore, this kind of approach also provides valuable information on the relative proportion of circulating strains, identifies new molecular viral forms as they arise, and allows the recognition of putative dual infections when different clade-specific probes hybridize to a single genomic region.…”

HIV Recombination and Pathogenesis – Biological and Epidemiological Implications

“…Subsubtype F1 is found in South America and Europe, whereas subtype F strains from Africa (eg Cameroon) more commonly belong to subsubtype F2 (Laukkanen et al, 2000). Subtype F also forms part of CRF12_BF, which has become widespread across South America, and more recently as a part of CRF17_BF, CRF28_BF and CRF29_BF, which have also been identified in South America (De Sa Filho et al, 2006;Hierholzer et al, 2002). CRF05_DF has also been reported in Europe, although is thought to have arisen in Africa (Casado et al, 2003;Laukkanen et al, 2000).…”