Window periods

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

  • Between three weeks (21 days) and six weeks (42 days)1
  • Between two and eight weeks, with an average of 25 days; 97% of people develop antibodies within three months2
  • 20-25 days3
  • 22 days4
  • One month5

Second-generation ELISAs were estimated to detect infection after 42 days and first-generation after 63 days.4

Related Links

References

  1. Branson BM State of the art for diagnosis of HIV infection. Clin Infect Dis 45:S221-225, 2007
  2. 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
  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. Parry JV et al. Towards error-free HIV diagnosis: guidelines on laboratory practice. Comm Dis Pub Health 6:334-350, 2003
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