Spreading of HIV-1 subtype G and envB/gagG recombinant strains among injecting drug users in Lisbon, Portugal.
We have evaluated the genetic diversity of HIV-1 strains infecting injecting drug users (IDUs) in Lisbon, Portugal. Heteroduplex mobility assay and/or phylogenetic analysis revealed that env (C2V3C3 or gp41) subtype B is present in 63.7% of the 135 viral samples studied, followed by subtypes G (23.7%), A (6.7%), F (5.2%), and D (0.7%). Similar analysis of gag (p24/p7) performed on 91 of the specimens demonstrated that 49.5% of the infections were caused by subtype G viruses; other gag subtypes identified were B (39.5%), F (3.3%), A and D (1.1.% each), and the recombinant circulating form CRF02_AG (5.5%). Discordant env/gag sub-types were detected in 34.1% of the strains and may reflect the presence of dual infections and/or recombinant viruses. The presumptive B/G recombinant form was highly predominant (21 of 31). The genetic pattern of HIV-1 subtype B and G strains is suggestive of multiple introductions and recombination episodes and of a longstanding presence of both subtypes in the country. C2V3C3 amino acid sequences from IDU-derived subtype G viruses presented highly significant signatures, which distinguish the variants from this transmission group. The unusually high prevalence of subtype G sequences (34.1%), independent of the geographic origin of the infected individuals, makes this IDU HIV-1 epidemic unique.
Esteves
Aida
A
Unidade de Virologia, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Lisbon, Portugal. aidaesteves@ihmt.unl.pt
Parreira
Ricardo
R
Piedade
João
J
Venenno
Teresa
T
Franco
Margarida
M
Germano de Sousa
José
J
Patrício
Luis
L
Brum
Paula
P
Costa
António
A
Canas-Ferreira
Wanda F
WF
D000293:Adolescent; D000328:Adult; D000595:Amino Acid Sequence; D005260:Female; D015752:Genes, env / Q000235:genetics*; D015750:Genes, gag / 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; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D011174:Portugal / Q000453:epidemiology; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D015819:Substance Abuse, Intravenous / Q000150:complications*