Tracing the origin and northward dissemination dynamics of HIV-1 subtype C in Brazil.
Previous studies indicate that the HIV-1 subtype C epidemic in southern Brazil was initiated by the introduction of a single founder strain probably originating from east Africa. However, the exact country of origin of such a founder strain as well as the origin of the subtype C viruses detected outside the Brazilian southern region remains unknown. HIV-1 subtype C pol sequences isolated in the southern, southeastern and central-western Brazilian regions (n = 209) were compared with a large number (n ~ 2,000) of subtype C pol sequences of African origin. Maximum-likelihood analyses revealed that most HIV-1 subtype C Brazilian sequences branched in a single monophyletic clade (CBR-I), nested within a larger monophyletic lineage characteristic of east Africa. Bayesian analyses indicate that the CBR-I clade most probably originated in Burundi and was introduced into the Paraná state (southern region) around the middle 1970s, after which it rapidly disseminated to neighboring regions. The states of Paraná and Santa Catarina have been the most important hubs of subtype C dissemination, and routine travel and spatial accessibility seems to have been the major driving forces of this process. Five additional introductions of HIV-1 subtype C strains probably originated in eastern (n = 2), southern (n = 2) and central (n = 1) African countries were detected in the Rio de Janeiro state (southeastern region). These results indicate a continuous influx of HIV-1 subtype C strains of African origin into Brazil and also unveil the existence of unrecognized transmission networks linking this country to east Africa.
Laboratório de AIDS e Imunologia Molecular, Instituto Oswaldo Cruz, FIOCRUZ, Rio de Janeiro, Brazil.
Edson
E
Delatorre
José C
JC
Couto-Fernandez
Monick Lindenmayer
ML
Guimarães
Ludimila Paula
LP
Vaz Cardoso
Keila Correia
KC
de Alcantara
Mariane Martins de Araújo
MM
Stefani
Hector
H
Romero
Caio C M
CC
Freire
Atila
A
Iamarino
Paolo M
PM
de A Zanotto
Mariza G
MG
Morgado
Gonzalo
G
Bello
D001938:Brazil / Q000453:epidemiology; D005838:Genotype; D015658:HIV Infections / Q000453:epidemiology* / Q000635:transmission / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D063426:Human Migration; D006801:Humans; D010802:Phylogeny; D058974:Phylogeography; D062211:Spatio-Temporal Analysis; D054302:pol Gene Products, Human Immunodeficiency Virus / Q000235:genetics
D054302:pol Gene Products, Human Immunodeficiency Virus