title: Global trends in molecular epidemiology of HIV-1 during 2000-2007.
abstract: OBJECTIVE
  To estimate the global and regional distribution of HIV-1 subtypes and recombinants between 2000 and 2007.
  
  
  METHODS
  Country-specific HIV-1 molecular epidemiology data were combined with estimates of the number of HIV-infected people in each country.
  
  
  METHODS
  Cross-sectional HIV-1 subtyping data were collected from 65 913 samples in 109 countries between 2000 and 2007. The distribution of HIV-1 subtypes in individual countries was weighted according to the number of HIV-infected people in each country to generate estimates of regional and global HIV-1 subtype distribution for the periods 2000-2003 and 2004-2007.
  
  
  RESULTS
  Analysis of the global distribution of HIV-1 subtypes and recombinants in the two periods indicated a broadly stable distribution of HIV-1 subtypes worldwide with a notable increase in the proportion of circulating recombinant forms (CRFs), a decrease in unique recombinant forms (URFs) and an overall increase in recombinants. In 2004-2007, subtype C accounted for nearly half (48%) of all global infections, followed by subtypes A (12%) and B (11%), CRF02_AG (8%), CRF01_AE (5%), subtype G (5%) and D (2%). Subtypes F, H, J and K together cause fewer than 1% of infections worldwide. Other CRFs and URFs are each responsible for 4% of global infections, bringing the combined total of worldwide CRFs to 16% and all recombinants (CRFs along with URFs) to 20%.
  
  
  CONCLUSIONS
  The global and regional distributions of individual subtypes and recombinants are broadly stable, although CRFs may play an increasing role in the HIV pandemic. The global diversity of HIV-1 poses a formidable challenge to HIV vaccine development.
authors.affiliation: Nuffield Department of Obstetrics and Gynaecology, University of Oxford, John Radcliffe Hospital, UK. joris.hemelaar@trinity.oxon.org
authors.forename: Joris
authors.initials: J
authors.lastname: Hemelaar
authors.forename: Eleanor
authors.initials: E
authors.lastname: Gouws
authors.forename: Peter D
authors.initials: PD
authors.lastname: Ghys
authors.forename: Saladin
authors.initials: S
authors.lastname: Osmanov
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D014644:Genetic Variation / Q000235:genetics*; D014943:Global Health; D015658:HIV Infections / Q000453:epidemiology / Q000235:genetics*; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006801:Humans; D008297:Male; D017720:Molecular Epidemiology; D011995:Recombination, Genetic; D012703:Serotyping