title: Molecular epidemiology of HTLV-2 infection among intravenous drug users in Spain.
abstract: BACKGROUND
  HTLV-2 infection is prevalent among intravenous drug users (IDUs), which often are coinfected with HIV-1. Two main subtypes, HTLV-2a and -2b, have been described among European IDUs, with a characteristically geographic distribution: IIa in northern Europe and IIb in the south. Although frequent traveling within Europe might have favoured a wide dissemination of diverse HTLV-2 variants, HTLV-2b was so far the only subtype reported in Spain.
  
  
  OBJECTIVE
  To investigate the current molecular epidemiology of HTLV-2 in Spain.
  
  
  METHODS
  Twenty-six new HTLV-2 strains isolated from IDUs over the last 11 years in different geographic regions were examined. The HTLV LTR region (620bp) was sequenced and phylogenetic analyses were performed. Endonuclease restriction sites were examined to further characterize the HTLV-2 subgroup.
  
  
  RESULTS
  All 26 individuals infected with HTLV-2 showed viruses belonging to the HTLV-2 b4 clade and were closely related to the previously reported HTLV-2 Spanish and Italian IDU isolates.
  
  
  CONCLUSIONS
  HTLV-2 subtype b4 continues to be the only HTLV-2 subgroup recognized so far in Spain and no introduction of other HTLV-2 variants has occurred over the last 11 years.
authors.affiliation: Service of Infectious Diseases, Hospital Carlos III, Madrid, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Toro
authors.forename: Berta
authors.initials: B
authors.lastname: Rodés
authors.forename: Sylvina
authors.initials: S
authors.lastname: Bassani
authors.forename: Victoria
authors.initials: V
authors.lastname: Jiménez
authors.forename: Concepción
authors.initials: C
authors.lastname: Tuset
authors.forename: María Teresa
authors.initials: MT
authors.lastname: Brugal
authors.forename: Luis
authors.initials: L
authors.lastname: de la Fuente
authors.forename: Vincent
authors.initials: V
authors.lastname: Soriano
mesh_terms: D000328:Adult; D005260:Female; D015491:HTLV-II Infections / Q000453:epidemiology*; D015367:Human T-lymphotropic virus 2 / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013030:Spain / Q000453:epidemiology; D015819:Substance Abuse, Intravenous / Q000150:complications*