Sex Transm Infect 82:i48-i51 doi:10.1136/sti.2005.016022
  • HIV

Criteria for detecting and understanding changes in the risk of HIV infection at a national level in generalised epidemics

  1. G P Garnett1,
  2. S Gregson1,
  3. K A Stanecki2
  1. 1Imperial College London, UK
  2. 2UNAIDS, Geneva, Switzerland
  1. Correspondence to:
 G P Garnett
 Department of Infectious Disease Epidemiology, Imperial College London, St Mary’s Campus, Norfolk Place, London W2 1PG, UK; g.garnett{at}


    Identification of causes of changes in prevalence and incidence of HIV at a national level is important for planning future prevention and intervention needs. However, the slow progression to disease and the sensitive and stigmatising nature of the associated behaviours can make this difficult. Changing rates of incidence are to be expected as an epidemic progresses, but separating background changes from those brought about by changes in behaviour and interventions requires careful analysis. This paper discusses the criteria required to determine whether observed changes in HIV prevalence are the result of changes in behaviour.


    • GPG and SG thank UNAIDS, the UK MRC, The Wellcome Trust, and the CDCP Zimbabwe for grant support

    • Competing interests: none declared

    • Edited by N Walker, H Ward and R Miller