title: HIV-1 subtypes D and F are prevalent in Guinea Conakry.
abstract: BACKGROUND
  Limited data is available upon the distribution of different HIV-1/2 genotypes in the blood donor population from Guinea Conakry.
  
  
  OBJECTIVE
  To investigate the prevalence of HIV-1/2 subtypes in asymptomatic blood donors in Guinea Conakry, in order to update knowledge of HIV-1/2 epidemiology within this country.
  
  
  METHODS
  Samples from 104 blood donors seropositive for HIV-1/2 were tested for HIV-1 by real-time RT-PCR. Those negative for HIV-1 were tested with HIV-2 nested RT-PCR. Positive samples were further amplified in the HIV-1 gag and pol regions and sequenced. Subtypes were determined by phylogenetic analysis on amplicon sequences.
  
  
  RESULTS
  61 samples were positive by HIV-1 real-time RT-PCR. Of the 43 negative, 2 (4.6%) were positive for HIV-2. 52/61 (85.3%) samples were positive by nested RT-PCR. Of the 52, 43 (70.5%) and 31(59.6%) sequences were obtained in the gag and pol regions, respectively; 23 for both regions. HIV-1 subtype distribution was 1 B (2.1%), 8 F (17%), 8 D (17%) and 28 CRF02_AG (59.6%) with 2 unclassified recombinants (4.3%). Unique clusters for subtype D and F distinguished Guinea from HIV-1 subtype distribution in neighboring countries.
  
  
  CONCLUSIONS
  Subtype F and subtype D strains, uncommon in West Africa, are a substantial part of HIV-1 epidemiology in Guinea.
authors.affiliation: Division of Transfusion Medicine, Dept of Haematology, University of Cambridge, Cambridge Blood Centre, Cambridge CB2 2PT, UK.
authors.forename: G L
authors.initials: GL
authors.lastname: Freimanis
authors.forename: A
authors.initials: A
authors.lastname: Loua
authors.forename: J P
authors.initials: JP
authors.lastname: Allain
mesh_terms: D000293:Adolescent; D000328:Adult; D001782:Blood Donors; D005260:Female; D016701:Guinea / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology; D015497:HIV-1 / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D015498:HIV-2 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D010802:Phylogeny; D015995:Prevalence; D055815:Young Adult