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Had unprotected sex. Rapid antibody test showed negative. Do I have HIV?

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General & Family Physician
Practicing since : 2012
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I am a female that had unprotected sex on 4 occasions with a male with unknown status. The last encounter was February 14, 2013. I had a rapid antibody test done on March 15, 2013 and again on May 3 which is 78 days from the last encounter at 11 weeks. All tests have been negative. Is it safe to say that I do not have HIV. I have heard that with the new advances of the antibody tests that at 8 weeks results are conclusive??
Posted Sat, 25 May 2013 in General Health
Answered by Dr. Achuo Ascensius 2 hours later
Thanks for the query.

Following an HIV infection, there is what is called sero-conversion which is the production of antibodies against the viral proteins. Sero-conversion usually takes an average of 30 days in most people but can take up to 6 months. HIV antibody tests are designed to test for the presence of such antibodies which become appreciable with time. Three months was the accepted period of time with a confirmation later at 6 months for the simple antibody ELISA.

With the advent of modern ELISA techniques for HIV that make use of both HIV antibodies and Antigen p24, the detection of HIV infection has been reduced to as low as three weeks.

We need to be sure you did take the fourth generation HIV ELISA in order to conclude that your chances of having the infection are low. Definite conclusion will be after re-testing 28 days from your last unprotected intercourse.

Hope this answers your query. If you do have further query, i will be glad to help.
Best regards
Above answer was peer-reviewed by
Follow-up: Had unprotected sex. Rapid antibody test showed negative. Do I have HIV? 41 minutes later
I took the one that you can buy at a drug store. The Oraquick oral fluid test that tests for HIV-1 and HIV-2 antibodies. If I tested at 11 weeks will my results change if I retest at 12 weeks??
Answered by Dr. Achuo Ascensius 23 minutes later
thanks one more for the query.

You did a rapid diagnostic test which makes us of antibodies produced by the body in response to the presence of the virus. 11 weeks would not be appropriate to conclude. Re-do the test once its three months and if its negative then you have a good chance of being negative when you do a control at 6 months post exposure.
However, doing an ELISA would greatly reduce the time for confirming the results and you won't have to be for up to 6 months ( 28 days rather).

Hope this answers your query. If you do have further query, i will be glad to help. If you do not have further query, you could close the discussion and rate the answers.
Best regards
Above answer was peer-reviewed by
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