4th generation test

Originally Posted: 
Friday, November 2, 2012


I'm a woman and I had unprotected sex with a man of unknown HIV status. 23 days after I had an HIV DUO test coming back negative. What is the percentage of the success of this test at 23 days after possible exposure. I found in the internet that p24 during this period is at its peak. So if i was infected this test would have detected it through p24 correct?

The reason why i worry too much is because i was diagnosed with another STD and the last month i was diagnosed twice with vaginal candida spp and tongue candida despite the fact that i was treated with antibiotics for candida. Now i have flu dry cough and i experienced once fever 37.6. Are these an indication of HIV?



Hi there,

Thank you for using the AIDS Vancouver Online Helpline as your source of HIV/AIDS related information. You are to be congratulated on being tested! Testing is the only true way to determine one's HIV and STI status.

The 4th generation EIA "Combo/DUO" test is a highly accurate test which looks for both antibodies to the virus and p24 protein antigen in your blood, if HIV is present. The test has an accuracy rate of 99.9% after 12 weeks post-exposure. You are right in stating that p24 is detectable only immediately after infection for the first few weeks. As such, the antibody test has  a window period of 4-12 weeks. Your results at 23 days are a good indication of your status and most specialists consider this DUO test conclusive at 6 weeks. As such, I would recommend re-testing at 42 days post-exposure to obtain conclusive results.

Antibiotic use would not affect your results as antibiotics are used to treat bacterial infections, and HIV is a virus. HIV cannot be diagnosed based on symptoms such as the flu-like symptoms often associated with early HIV infection as these could be symptoms of other things as well.

Use of protection (condoms) greatly reduces your risk of contracting not just HIV, but many sexually transmitted infections (STIs). In addition to undergoing regular STI testing if you are sexually active, I would recommend using protection based on your preferences.

I hope this helped to answer your question and please do not hesitate to ask if you have any further concerns.

In Health,
AIDS Vancouver Helpline Volunteer
E-mail: helpline@aidsvancouver.org
Phone (Mon-Fri 9am-4pm): (604) 696-4666
Web: www.aidsvancouver.org/helpline

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