AEGiS-13IAC: Molecular epidemiology of HIV-1 in South America.

13th International AIDS Conference

Durban, South Africa - July 9-July 14, 2000

Molecular epidemiology of HIV-1 in South America.

Int Conf AIDS 2000 Jul 9-14; 13:(abstract no. TuOrA410)

Russell K, Sanchez J, Carcamo C, Negrete M, Blanco JC, Jimenez AG, Avila M, Martinez L, Serra M, Russi J, Alava A, Gianella A, Andrade R, Carr JK
K. Russell, Embajada Americana, c/o US NMRCD, Av. La Encalada Cuadra 17, Monterrico, Santiago de Surco, Lima, Peru, Tel.: +51 1 562 38 80, Fax: +51 1 561 30 42, E-mail: russell@namrid.sld.pe

BACKGROUND: Genotypic differences may be reflected in antigenic differences; therefore, knowledge of circulating genotypes of HIV-1 becomes important as vaccine trials become a reality. The U.S. Navy Medical Research Center Detachment in Lima, Peru in collaboration with the Pan American Health Organization, respective Ministry of Health AIDS Programs and risk-group related NGOs, has created an HIV surveillance network in 8 countries of South America in the last two years. The objective of this collaborative effort is to monitor the circulating genotypes of HIV-1 while conducting population-based prevalence studies in well-defined at-risk populations.

METHODS: Those found to be positive in the prevalence studies as well as a convenience sampling of other known HIV positive patients were recruited for genotyping, dried blood spots (DBS) or PBMCs collected, and DNA extracted. Genotype was first determined with the heteroduplex mobility assay (HMA); sequencing confirmed a selected number.

RESULTS: Prevalence of HIV in 8 different at-risk populations throughout South America ranged from 0.6% to 22.2%, with a total of over 10,000 individuals surveyed. Among 825 HIV + samples collected from 6 countries for genotyping, genotype B was found to predominant in all countries but Argentina. The majority of infections in HIV+ maternity patients in Argentina and nearly half of infections identified in Uruguay were genotype F. Total number of samples processed for genotype determination to date: 597 with 76.7% (458) genotype B, 23% (137) genotype F, 0.15% (1) genotype C and 0.15% (1) genotype A. Discussion: Subtype B continues to be the most prevalent genotype of HIV-1 identified in most of the countries surveyed in South America. However, in Argentina and to a lesser extent Uruguay, subtype F has a surprisingly high prevalence. Continued surveillence of HIV in South America, including the molecular epidemiology, is clearly warranted as we move toward vaccine trials.

Keywords: AEGIS, HIV-1, Epidemiology, Molecular, HIV Infections, South America, Prevalence, HIV Seropositivity, Genotype, Acquired Immunodeficiency Syndrome, Cross-Sectional Studies, Argentina, Uruguay, Peru, United States, Human, genetics
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TuOrA410