Timing of the introduction into Ethiopia of subcluster C' of HIV type 1 subtype C.
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.
Abebe
A
A
Ethiopian-Netherlands AIDS Research Project (ENARP), Ethiopian Health and Nutrition Research Institute (EHNRI), Addis Ababa, Ethiopia. almazab@enarp.com
Lukashov
V V
VV
Rinke De Wit
T F
TF
Fisseha
B
B
Tegbaru
B
B
Kliphuis
A
A
Tesfaye
G
G
Negassa
H
H
Fontanet
A L
AL
Goudsmit
J
J
Pollakis
G
G
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
D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments