title: Segregation of human immunodeficiency virus type 1 subtypes by risk factor in Australia.
abstract: The aim of this study was to determine which human immunodeficiency virus type 1 (HIV-1) subtypes were circulating in Australia and to correlate the subtypes with risk factors associated with the acquisition of HIV-1 infection. DNA was extracted from peripheral blood mononuclear cells, and HIV-1 env genes were amplified and subtyped using heteroduplex mobility analysis, with selected samples sequenced and phylogenetic analysis performed. The HIV-1 env subtypes were determined for 141 samples, of which 40 were from female patients and 101 were from male patients; 13 samples were from children. Forty-seven patients were infected by homosexual or bisexual contact, 46 were infected through heterosexual contact, 21 were infected from injecting drug use (IDU), 13 were infected by vertical transmission, 8 were infected from nosocomial exposure, and 6 were infected by other modes of transmission, including exposure to blood products, ritualistic practices, and two cases of intrafamilial transmission. Five subtypes were detected; B (n = 104), A (n = 5), C (n = 17), E (CRF01_AE; n = 13), and G (n = 2). Subtype B predominated in HIV-1 acquired homosexually (94% of cases) and by IDU (100%), whereas non-subtype B infections were mostly seen in heterosexually (57%) or vertically (22%) acquired HIV-1 infections and were usually imported from Africa and Asia. Subtype B strains of group M viruses predominate in Australia in HIV-1 transmitted by homosexual or bisexual contact and IDU. However, non-B subtypes have been introduced, mostly acquired via heterosexual contact.
authors.affiliation: Center for Virus Research, Westmead Millennium Institute, Westmead Hospital, Westmead, NSW 2145, Australia.
authors.forename: Belinda L
authors.initials: BL
authors.lastname: Herring
authors.forename: Ying C
authors.initials: YC
authors.lastname: Ge
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Mala
authors.initials: M
authors.lastname: Ratnamohan
authors.forename: Frank
authors.initials: F
authors.lastname: Zheng
authors.forename: Anthony L
authors.initials: AL
authors.lastname: Cunningham
authors.forename: Nitin K
authors.initials: NK
authors.lastname: Saksena
authors.forename: Dominic E
authors.initials: DE
authors.lastname: Dwyer
mesh_terms: D000328:Adult; D001315:Australia / Q000453:epidemiology; D004279:DNA, Viral / Q000097:blood; D005260:Female; D015686:Gene Products, env / Q000235:genetics; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission / Q000821:virology*; D015497:HIV-1 / Q000145:classification* / Q000235:genetics; D020180:Heteroduplex Analysis; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D012307:Risk Factors; D017422:Sequence Analysis, DNA
chemical_list: D004279:DNA, Viral; D015686:Gene Products, env