In-depth analysis of the origins of HIV type 1 subtype C in South America.
The South American HIV-1 epidemic is characterized by the co-circulation of subtype B and BF recombinant variants. Together with the B and BF genotypes, HIV-1 subtype C (HIV-1C), F1, and several other recombinants have been reported. The epidemiological significance and immune correlates of these "non-B-non-BF" strains circulating in South America are still uncertain and therefore are increasingly attracting the interest of the scientific community. In this study, the South American HIV-1C epidemic was studied using new technologies for the phylogenetic analysis of large datasets. Our results indicate that there is a major clade encompassing most of the South American HIV-1C strains. These analyses also agreed that some strains do not group inside this major clade, suggesting that there could be HIV-1C sequences of different origins circulating in South America. Others have proposed different hypotheses about the origins of HIV-1C strains from South America. This study shows that an exact single origin cannot be determined, a fact that could be attributed to sampling problems, phylogenetic uncertainty, and the shortage of historical and epidemiological data. Currently, the reported data indicate that HIV-1C strains were introduced in Brazil and afterward spread to other regions of South America. By using character optimization on the obtained phylogenetic trees, we observed that Argentina could also be a point in which the HIV-1C epidemic entered South America.
Centro Nacional de Referencia para el SIDA, Departamento de Microbiología, Facultad de Medicina, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina. lrj@efpu.org.ar
Leandro R
LR
Jones
Darío A
DA
Dilernia
Julieta M
JM
Manrique
Franco
F
Moretti
Horacio
H
Salomón
Manuel
M
Gomez-Carrillo
D016000:Cluster Analysis; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D013020:South America / Q000453:epidemiology