AEGiS-15IAC: Extensive HIV genetic diversity existed in Africa by the mid-1980s along with distinct patterns of epidemic strains in Burkina Faso and Zaire.

15th International AIDS Conference

Bangkok, Thailand - July 11-16, 2004

Extensive HIV genetic diversity existed in Africa by the mid-1980s along with distinct patterns of epidemic strains in Burkina Faso and Zaire.

Int Conf AIDS 2004 Jul 11-16; 15:(abstract no. ThOrC1362)

Kalish ML, Pieniazek D, Robbins KE, Schaefer A, Nzilambi N, Quinn TC, St ME
Louis, A.S. Youngpairoj, H.W. Jaffe, M.A. Rayfield, T.M. Folks. Centers for Disease Control and Prevention, Atlanta, GA, United States

BACKGROUND: Most of our knowledge of the global HIV epidemic has come from phylogenetic analysis of full or partial genome sequences derived from recently collected blood samples. To gain a clearer understanding of the evolutionary history of HIV, we analyzed serum samples from West and Central Africa collected in the mid-1980s.

METHODS: 3,988 serum samples from Kinshasa, Zaire (Central Africa) collected in 1984 and 1986, and 849 samples from Ouagadougou, Burkina Faso (West Africa) collected in 1986 were screened for HIV-1 infections by EIA and confirmed with either Western blot or the InnoLia line assay. Seropositive samples were subjected to RT-PCR using primers from: gp41, C2V3C3 (env), p17 (gag), protease (PR), and/or integrase (pol). Amplified products were sequenced and phylogenetically analyzed.

RESULTS: A much greater diversity of HIV strains was found in Kinshasa where virtually all the HIV-1 subtypes (with high intrasubtype diversity) and unclassifiable gene regions were identified; at least 37% represented recombinant viruses. A limited HIV-1 diversity was found in Ouagadougou. Of 132 gp41 or PR strains, 65.2% clustered with the complex circulating recombinant form 06 (CRF06_cpx) sequences; and 28% clustered with CRF02_AG. Both showed a low intra-CRF genetic diversity. In addition, HIV-2 subtypes A and B were found as either monotypic HIV-2 infections or as heterotypic HIV-1 and HIV-2 infections.

CONCLUSIONS: Extensive HIV genetic diversity existed in Africa by the mid-1980s. However, distinct patterns of regional or country-wide epidemics were already apparent. The greatest diversity of subtypes and unclassifiable strains was found in Central Africa, consistent with this region of Africa being the epicenter of the HIV-1, group M global epidemic. Both HIV-1 and HIV-2 subtypes A and B were present in Burkina, Faso, along with a limited HIV-1 diversity compared to that seen in Kinshasa. The HIV-1 epidemic in West Africa appears to have had a more recent introduction caused by a limited number of founder viruses.

Keywords: AEGIS, HIV, Acquired Immunodeficiency Syndrome, HIV Seropositivity, HIV-1, HIV Infections, Variation (Genetics), Africa, Central, Genes, env, Genes, gag, Democratic Republic of the Congo, HIV Envelope Protein gp120, Genes, pol, Disease Outbreaks, HIV Core Protein p24, HIV-2, Africa, HIV Envelope Protein gp41, Burkina Faso, genetics, immunology

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