AEGiS-11IAC: Distinct HIV-1 subtypes associated with different risk groups in South Africa.

11th International AIDS Conference


Vancouver, British Columbia — July 7-12, 1996

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Distinct HIV-1 subtypes associated with different risk groups in South Africa.

Int Conf AIDS 1996 Jul 7-12; 11:216 (abstract no. Tu.A.101)
Williamson C, Engelbrecht S, van Harmelen J, van Rensburg EJ, Bredell W, Wood R; Department of Medical Microbiology, University of Cape Town Medical School, South Africa. Fax: 21-448-4110. E-mail: cwilliam@medmicro.uct.ac.za.

OBJECTIVES: To determine HIV-1 subtypes in different risk groups in Cape Town, South Africa.

METHODS: DNA was isolated from blood drawn from 84 patients attending local clinics. Samples were divided into 4 groups according to presumed mode of transmission: homosexual/bisexual (n=37), heterosexual/vertical (n=42), blood transfusion (n=2), and mode of transmission unknown (n=3). Proviral DNA was subtyped by HMA based on the 700 bp V3-V5 region of the env gene (47 samples) and/or by sequence analysis of the gag gene (500 bp region encoding the p17 protein) (54 samples). Phylogenetic trees were generated using both neighbour-joining and maximum parsimony approaches.

RESULTS: Subtypes B, C, D and E were identified. Subtypes were found to segregate according to mode of transmission, with subtype B viruses found in 86 % (32/37) of the homosexual/bisexual group and subtype C viruses found in 83% (35/42) of the heterosexual/vertical transmission group. Subtype B viruses were also found in 5 heterosexual patients, 2 patient infected by blood transfusion and in 3 patients where the mode of transmission was unknown. Subtype D viruses were found in 5 homosexual patients and one heterosexual patient. A subtype E virus was identified in a heterosexual patients No discrepancy was found in subtype designation between samples analysed in the gag and env region (n=19).

CONCLUSIONS: The initial epidemic in South Africa in the early 1980s affected mainly the homosexual population and shifted to a predominantly heterosexual epidemic by the late 1980s. In this study, subtype B viruses were associated with homosexual transmission and subtype C viruses with heterosexual transmission, suggesting two independent epidemics.

Keywords: AEGIS, HIV-1, Genes, gag, Genes, env, Heterosexuality, Risk, South Africa, Human, transmission, genetics, ICA11KWDaegis,hiv-1,genes,gag,genes,env,heterosexuality,risk,southafrica,human,transmission,genetics,ica11

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TuA101

Copyright © 1996 - International AIDS Society (IAS). Reproduction of this abstract (other than one copy for personal reference) must be cleared through the IAS.