Window periods

The addition of testing for antigen reduces the window period by around five days, compared to third-generation tests.

Different authorities give slightly different estimates for the duration of the window period between exposure and the ability of fourth-generation tests to detect infection:

  • Eleven to 16 days1
  • 14 days2
  • 16 days3
  • Approximately two and a half weeks4
  • Three to four weeks after exposure5
  • Between 24.5 and 26 days after exposure6
  • One month7
Related Links

References

  1. Coombs RW Clinical laboratory diagnosis of HIV-1 and use of viral RNA to monitor infection. In Holmes KK (editor), Sexually Transmitted Diseases. New York: McGraw-Hill, 2008
  2. Ly TD et al. Evaluation of the sensitivity and specificity of six HIV combined p24 antigen and antibody assays. J Virol Methods 122:185-94, 2004
  3. Maldarelli F Diagnosis of Human Immunodeficiency Virus infection. In Mandell, Douglas and Bennett’s Principles and Practice of Infectious Diseases (sixth edition). Philadelphia: Elsevier Churchill Livingstone, 2004
  4. Branson BM State of the art for diagnosis of HIV infection. Clin Infect Dis 45:S221-225, 2007
  5. Parry JV et al. Towards error-free HIV diagnosis: guidelines on laboratory practice. Comm Dis Pub Health 6:334-350, 2003
  6. Haute Autorité de santé Dépistage de l’infection par le VIH en France: Modalités de réalisation des tests de dépistage, argumentaire. www.has-sante.fr, 2008
  7. British HIV Association, British Association for Sexual Health and HIV, Children’s HIV Association. Don’t forget the children: Guidance for the HIV testing of children with HIV-positive parents. Available at http://www.chiva.org.uk/health/conferences/previous/dontforget (accessed 29 April 2010), 2009