HIV-1 genetic diversity in Galicia Spain: BG intersubtype recombinant viruses circulating among injecting drug users.
BACKGROUND
The HIV-1 epidemics in Western Europe are dominated by B subtype viruses. Non-B subtype is largely restricted to individuals infected outside of Europe and to their direct contacts and is generally acquired by the heterosexual route.


METHODS
Protease and a segment of reverse transcriptase were amplified and sequenced from plasma RNA in 451 individuals from seven cities of Galicia, north-western Spain. Subtype sequence homologies were determined using the BLAST algorithm. Non-B sequences were examined by phylogenetic analysis and intersubtype recombination by bootscanning. The env V3 region was analysed in all non-B and in 38 B subtype viruses.


RESULTS
Ten different non-B genetic forms were identified in 20 (4.4%) individuals. Subtypes were concordant between pol and V3 in five viruses; 14 (70%) infections were with intersubtype recombinant viruses, and one individual had a dual B+G infection. Seven recombinant viruses were phylogenetically related to five reported recombinant forms. Three non-recombinant G and six recombinant BG viruses formed a monophyletic cluster for pol. All but three individuals with non-B infections were native Spanish. Only 6 of 16 individuals referred to sexual contacts with sub-Saharan Africans. Twelve (60%) non-B subtype infections, including all with G and BG viruses, were in injecting drug users (IDU).


CONCLUSIONS
Non-B subtype viruses were identified in 4.4%, with a high diversity of genetic forms, including 70% infections with intersubtype recombinant viruses. The majority of individuals with non-B infections were IDU, most of them without known contacts with non-European sources, and among whom BG recombinant viruses are circulating.
Area de Patogenia Viral, Centro Nacional de Biología Fundamental, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
M M
MM
Thomson
E
E
Delgado
N
N
Manjón
A
A
Ocampo
M L
ML
Villahermosa
A
A
Mariño
I
I
Herrero
M T
MT
Cuevas
E
E
Vázquez-de Parga
L
L
Pérez-Alvarez
L
L
Medrano
J A
JA
Taboada
R
R
Nájera
D000328:Adult; D005260:Female; D015751:Genes, pol / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D015699:HIV Envelope Protein gp120 / Q000235:genetics*; D015658:HIV Infections / Q000453:epidemiology / Q000821:virology*; D016333:HIV Protease / Q000235:genetics; D054303:HIV Reverse Transcriptase / Q000235:genetics; D015497:HIV-1 / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010446:Peptide Fragments / Q000235:genetics*; D010802:Phylogeny; D012367:RNA, Viral / Q000032:analysis; D011995:Recombination, Genetic; D017423:Sequence Analysis, RNA; D013030:Spain / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000821:virology*
D015699:HIV Envelope Protein gp120; C059762:HIV envelope protein gp120 (305-321); D010446:Peptide Fragments; D012367:RNA, Viral; D054303:HIV Reverse Transcriptase; D016333:HIV Protease