[Question #2873] 5th Generation Testing

40 months ago
Good afternoon. 

I had brief unprotected sex with oral sex and he ejaculated in my mouth with a heterosexual male that said he is clean. 

I had a test done at 9 weeks (63 days) and it all came out clean. I had a 5th generation HIV test. 

Question #1: how do antigen and antibodies work? Will the test detect one or the other? 

Question #2: will the test at 9 weeks be Conclusive? Should I retest?

Question #3: I’ve been having some back pain and some muscle pain. These wouldnt be symptoms right? 

Thank you!
Edward W. Hook M.D.
Edward W. Hook M.D.
40 months ago
Welcome to our Forum.  I'll be glad to comment and t provide some information.  The exposure you describe was very, very low risk,  HIV is very uncommon (less than 1 in 1000) among heterosexual men and the risk of acquiring HIV from performing oral sex on an infected man is less than 1 infection for every 10,000 exposures.  Thus, statistically your risk for infection is less than 1 in 10 million, even before you were tested.  Your test at 9 weeks now proves that you were not infected.

I am not familiar with the term "5th generation" tests and suspect that you were tested with a combination HIV antigen/antibody test which is sometimes referred to as a 4th generation test.  These tests provide results which are conclusive at any time more than 6 weeks after exposure.  The tests test for both HIV antigen (which is part of the virus itself and is detectable before the body has produced antibodies to the virus) and antibodies (which are infection-fighting proteins made by the body in response to infection).  By testing for both antigen and antibody, infections are detected sooner than they would be if testing was only performed for the virus. 

As to your questions:
1.  See above.  If a person has HIV infection these tests will detect either antigen (virus) or antibodies, or both.
2.  There is no need for further testing.  you have proved that you were not infected.
3.  Your test results prove that your muscle and back pain are not due to HIV infection

I hope this information is helpful.  If there are further questions or if any of this is unclear, you may ask up to two follow-up questions for clarification.  Take care.  EWH
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40 months ago
Thank you for your reply!

I understand that the antibody latches i to the antigen and eliminates it.  Which means that the antigen is undetectable, the antibodies will be detected. Is this correct? 

Also, will everyone make antigens? 

I’m sorry doctor, I’ve been battling with this for close to three months. 
Edward W. Hook M.D.
Edward W. Hook M.D.
40 months ago
The antigen is part of the virus. Antibodies are part of the way the body fights the infection.  When someone becomes infected, the antigens are present first, then the antibodies appear.  On some occasions both antigens and antibodies will be present.  When someone has been infected with HIV, after the passage of six weeks, every infected person will have antigens and/or antibodies which will be detected by the test.  Your nine week test was negative which PROVES that you were not infected.  EWH
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40 months ago
Ive heard people say that the 12 week mark is necessary to prove the conclusive results.  Several physicians say this, but then my physician said it’s not necessary. 

So that’s why I was a bit skeptical about the test. Is there any reason I should go get retested at 12 weeks? I’ve seen so many things on the internet, to the point where my anxiety levels were so high, I had anxiety attacks. 
Edward W. Hook M.D.
Edward W. Hook M.D.
40 months ago
Thank you for the explanation.  It helps me to understand your perspective.  The persons you have heard this from, perhaps including physicians, are out of date.  Several years ago it was believed that tests were not conclusive until 12 weeks had passed since an exposure.  Since then the tests have changed (earlier tests did not test for the presence of HIV antigen, only antibodies) and are improved and we have continued to learn about the disease.  I do this every day, day in and day out, and I can say with confidence that your results are entirely conclusive and there is no medical or scientific reason for further testing.  You may continue to test if you wish but the results are not going to change as a result of the exposure you have described.  EWH
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40 months ago
Thank you doctor. 

You don’t know how much you’ve helped me with this issue. 

Keep up the amazing work! 
Edward W. Hook M.D.
Edward W. Hook M.D.
40 months ago
I' pleased I could help.  This thread will close now.  Take care.  EWH---