title: A recent outbreak of human immunodeficiency virus type 1 infection in southern China was initiated by two highly homogeneous, geographically separated strains, circulating recombinant form AE and a novel BC recombinant.
abstract: New outbreaks of human immunodeficiency virus type 1 (HIV-1) among injecting drug users (IDUs) are spreading in China along heroin trafficking routes. Recently, two separate HIV-1 epidemics among IDUs were reported in Guangxi, Southern China, where partial sequencing of the env gene showed subtype C and circulating recombinant form (CRF) AE. We evaluated five virtually full-length HIV-1 genome sequences from IDUs in Guangxi to determine the genetic diversity and the presence of intersubtype recombinants. Sequence analysis showed two geographically separated, highly homogeneous HIV-1 strains. B/C intersubtype recombinants were found in three IDUs from Baise City, in a mountainous region near the Yunnan-Guangxi border. These were mostly subtype C, with portions of the capsid and reverse transcriptase (RT) genes from subtype B. The subtype B portion of the capsid was located in the N-terminal domain, which has been shown to influence virus core maturation, virus infectivity, and binding to cyclophilin A, whereas the subtype B portion of RT was located in the palm subdomain, which is the active site of the enzyme. These BC recombinants differed from a BC recombinant found in Xinjiang Province in northwestern China. CRF AE strains were found in IDUs from Nanning, the capital of Guangxi, and in IDUs from Pingxiang City near the China-Vietnam border. The AE and BC recombinants were both remarkable for their low interpatient diversity, less than 1% for the full genome. Rapid spread of HIV-1 among IDUs may foster the emergence of highly homogeneous strains, including novel recombinants in regions with multiple subtypes.
authors.affiliation: Department of Molecular Microbiology and Immunology, The Johns Hopkins School of Hygiene and Public Health, Baltimore, Maryland 21205, USA.
authors.forename: S
authors.initials: S
authors.lastname: Piyasirisilp
authors.forename: F E
authors.initials: FE
authors.lastname: McCutchan
authors.forename: J K
authors.initials: JK
authors.lastname: Carr
authors.forename: E
authors.initials: E
authors.lastname: Sanders-Buell
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: R
authors.initials: R
authors.lastname: Wagner
authors.forename: H
authors.initials: H
authors.lastname: Wolf
authors.forename: Y
authors.initials: Y
authors.lastname: Shao
authors.forename: S
authors.initials: S
authors.lastname: Lai
authors.forename: C
authors.initials: C
authors.lastname: Beyrer
authors.forename: X F
authors.initials: XF
authors.lastname: Yu
mesh_terms: D000163:Acquired Immunodeficiency Syndrome / Q000453:epidemiology*; D000328:Adult; D000595:Amino Acid Sequence; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D015497:HIV-1 / Q000145:classification* / Q000235:genetics; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D011995:Recombination, Genetic; D016415:Sequence Alignment; D015819:Substance Abuse, Intravenous / Q000150:complications*