title: The epidemiology of HIV infection among young people aged 15-24 years in southern Africa.
abstract: OBJECTIVE
  To investigate epidemiological patterns and trends of HIV infection and sexual behaviour among young people aged 15-24 years in the nine countries in southern Africa most affected by the HIV epidemic.
  
  
  METHODS
  Data on HIV prevalence among young people in the general population were obtained from national population-based surveys conducted between 2000 and 2007, whereas data on sexual behaviour were obtained from repeat surveys between 1994 and 2007. Linear or exponential regression was used to analyse HIV prevalence trends among young women attending antenatal clinics in recent years.
  
  
  RESULTS
  Patterns of HIV infection among young people are similar across the countries included in this analysis. The prevalence of HIV increases after the age of 15 years, more rapidly among women than among men, reaching a peak among women in their twenties and men in their thirties. Between 2000 and 2007 the prevalence of HIV among antenatal clinic attendees was constant in Mozambique and South Africa and declining in Lesotho, Namibia, Swaziland, Zambia, Botswana, Malawi and Zimbabwe, but only reached statistical significance (P < 0.05) in the last three. Changes towards safer sexual behaviour were observed over time among young men and women in the general population in this region.
  
  
  CONCLUSIONS
  Sexual behaviour changes among young people are encouraging and are associated with declines in HIV prevalence among young antenatal clinic attendees over time. More research is needed to understand the recent changes and the very high prevalence among young women in this region. Interventions aimed at reducing risky behaviour need to be supported and expanded while incorporating new approaches to prevention.
authors.affiliation: Evidence, Monitoring and Policy Department, UNAIDS, Geneva, Switzerland. gouwse@unaids.org
authors.forename: Eleanor
authors.initials: E
authors.lastname: Gouws
authors.forename: Karen A
authors.initials: KA
authors.lastname: Stanecki
authors.forename: Rob
authors.initials: R
authors.lastname: Lyerla
authors.forename: Peter D
authors.initials: PD
authors.lastname: Ghys
mesh_terms: D000293:Adolescent; D000328:Adult; D000353:Africa, Southern / Q000453:epidemiology; D017677:Age Distribution; D003430:Cross-Sectional Studies; D004196:Disease Outbreaks; D005260:Female; D015658:HIV Infections / Q000453:epidemiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology; D011295:Prenatal Care / Q000706:statistics & numerical data; D015995:Prevalence; D012725:Sexual Behavior / Q000706:statistics & numerical data; D055815:Young Adult