title: Timing of the introduction into Ethiopia of subcluster C' of HIV type 1 subtype C.
abstract: Viruses circulating in Ethiopia during the 1990s cluster with main subtype C, but a significant subcluster, C', was noted in multiple analyses. This subcluster of subtype C(C') was in a fifty-fifty equilibrium with the main subtype C (Abebe et al., AIDS Res Hum Retroviruses 2000;16:1909-1914). To analyze genetic diversification within the subcluster of HIV-1 subtype C designated C' in the course of the epidemic in Ethiopia, we analyzed 165 env gp120 V3 sequences obtained between 1988 and 1999. We observed a highly significant positive correlation between sampling years of individual sequences and their synonymous distances to the reconstructed common ancestor of the HIV-1 subtype C' subcluster. The extrapolation of the regression line of synonymous distances back to the date when no synonymous heterogeneity was present among the Ethiopian HIV-1 C' population allowed us to estimate 1982 (95% CI, 1980-1983) as the year of the onset of HIV-1 C' genetic diversification and expansion in Ethiopia. These results are in agreement with retrospective epidemiological and serological data, which demonstrated the absence of an HIV-1 epidemic in the Ethiopian population before the 1980s.
authors.affiliation: Ethiopian-Netherlands AIDS Research Project (ENARP), Ethiopian Health and Nutrition Research Institute (EHNRI), Addis Ababa, Ethiopia. almazab@enarp.com
authors.forename: A
authors.initials: A
authors.lastname: Abebe
authors.forename: V V
authors.initials: VV
authors.lastname: Lukashov
authors.forename: T F
authors.initials: TF
authors.lastname: Rinke De Wit
authors.forename: B
authors.initials: B
authors.lastname: Fisseha
authors.forename: B
authors.initials: B
authors.lastname: Tegbaru
authors.forename: A
authors.initials: A
authors.lastname: Kliphuis
authors.forename: G
authors.initials: G
authors.lastname: Tesfaye
authors.forename: H
authors.initials: H
authors.lastname: Negassa
authors.forename: A L
authors.initials: AL
authors.lastname: Fontanet
authors.forename: J
authors.initials: J
authors.lastname: Goudsmit
authors.forename: G
authors.initials: G
authors.lastname: Pollakis
mesh_terms: D000595:Amino Acid Sequence; D016384:Consensus Sequence; D005002:Ethiopia / Q000453:epidemiology; D014644:Genetic Variation; D015699:HIV Envelope Protein gp120 / Q000737:chemistry; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D016415:Sequence Alignment; D013997:Time Factors
chemical_list: D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments