HIV-2 CRF01_AB: first circulating recombinant form of HIV-2.
BACKGROUND
Five HIV-2-seropositive cases were recently identified in Japan, outside the HIV-2 endemic area of West Africa. To clarify the molecular epidemiology of HIV-2 in Japan, we analyzed sequences of these cases in detail.


METHODS
HIV-2 genetic groups were determined by gag and env sequences. For suspected recombinant isolates, the genetic structure was determined by full-length genomic analyses. To understand the history and evolution of HIV-2 recombinant isolates, we estimated the time of most recent common ancestor by Bayesian Markov chain Monte Carlo method.


RESULTS
Three isolates were determined as recombinants of groups A and B, and their mosaic genome structures were identical with that of 7312A, a recombinant isolate reported in 1990 from Côte d'Ivoire. Our 3 isolates and 7312A fulfilled the criteria for determining a circulating recombinant form (CRF). These isolates were verified by the Los Alamos HIV sequence database as the first CRF of HIV-2, HIV-2 CRF01_AB. The mean time of most recent common ancestor of CRF01_AB was estimated as between 1964 and 1973, several decades after the estimated emergence of HIV-2.


CONCLUSIONS
We recently identified HIV-2 CRF01_AB cases in Japan. This ectopic observation of the virus outside its original endemic area suggests an ongoing global spread of HIV-2 CRF01_AB.
Ibe
Shiro
S
Department of Infection and Immunology, Clinical Research Center, National Hospital Organization Nagoya Medical Center, Nagoya, Japan.
Yokomaku
Yoshiyuki
Y
Shiino
Teiichiro
T
Tanaka
Rie
R
Hattori
Junko
J
Fujisaki
Seiichiro
S
Iwatani
Yasumasa
Y
Mamiya
Naoto
N
Utsumi
Makoto
M
Kato
Shingo
S
Hamaguchi
Motohiro
M
Sugiura
Wataru
W
D000328:Adult; D001483:Base Sequence; D005260:Female; D015967:Gene Expression Regulation, Viral; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology*; D015498:HIV-2 / Q000145:classification / Q000235:genetics*; D054298:Human Immunodeficiency Virus Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D016865:Reassortant Viruses; D019562:Viral Load
D054298:Human Immunodeficiency Virus Proteins