title: Global and regional distribution of HIV-1 genetic subtypes and recombinants in 2004.
abstract: OBJECTIVE
  To estimate the global and regional distribution of HIV-1 subtypes and recombinants in 2004.
  
  
  METHODS
  A study was conducted in which molecular epidemiological data on HIV-1 subtype distribution in individual countries were combined with country-specific estimates of the number of people living with HIV.
  
  
  METHODS
  HIV-1 subtype data were collected for 23 874 HIV-1 samples from 70 countries, which together accounted for 89% of all people living with HIV worldwide in 2004. The proportions of HIV-1 infections due to various subtypes detected in each country were combined with the number of HIV infected people in the respective countries to generate regional and global HIV-1 subtype distribution estimates.
  
  
  RESULTS
  Subtype C accounted for 50% of all infections worldwide in 2004. Subtypes A, B, D and G accounted for 12%, 10%, 3% and 6%, respectively. The subtypes F, H, J and K together accounted for 0.94% of infections. The circulating recombinant forms CRF01_AE and CRF02_AG each were responsible for 5% of cases, and CRF03_AB for 0.1%. Other recombinants accounted for the remaining 8% of infections. All recombinant forms taken together were responsible for 18% of infections worldwide.
  
  
  CONCLUSIONS
  Combining data on HIV-1 subtype distribution in individual countries with country-specific estimates of the number of people living with HIV provided a good method to generate estimates of the global and regional HIV-1 genetic diversity in 2004. The results could serve as an important resource for HIV scientists, public health officials and HIV vaccine developers.
authors.affiliation: WHO/UNAIDS HIV Vaccine Initiative, Geneva, Switzerland.
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: D014644:Genetic Variation; D014943:Global Health; D015658:HIV Infections / Q000453:epidemiology* / Q000821:virology; D015497:HIV-1 / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D011995:Recombination, Genetic