[Question #2339] 4th generation RAPID DETERMINE test negative

45 months ago
Hello Dr,

Im a male that encouters TS escorts. The only unprotected sex I have is oral sex. (I perform fellatio on them). I have had three possible exposures. All the fellatios were with no ejaculation. I have good oral health but the only thing that worries me is that my gums are sensitive and bleed easily. I took a 4th generation rapid DETERMINE test that checks antigens & antibodies and the result was negative. 

Exposures prior to test were: 
1) 60 days (8.5 weeks)
2) 52 days (7.5 weeks)
3) 24 days (3.5 weeks)

I know that the test probably wont cover the third possible exposure but what about the other two? Is the negative result of the test a strong encouraging point? 

Thank you so much for your time. 
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
45 months ago
Welcome to the forum. Thanks for your succinct question. My reply is similar.

Performing oral sex on men (fellatio) very rarely transmits HIV. One estimate, from the US Centers for Disease Control and Prevention, is that if the penile partner is infected, transmission risk per event averages 1 in 10,000. That's equivalent to giving BJs to infected men once daily for 27 years before infection might be likely. Your risk might be lower, because of no ejaculation in your mouth. And you don't know your partners had HIV. So your risk is extremely low. If these are your only potential HIV risk events, I expect any and all your HIV tests to remain negative forever. 

The Determine test is very good, and your negative results at 52 and 60 days were conclusive. The 24 day negative test is around 90-95% conclusive, but you'll need a final test at 6 weeks in order to be truly definitive. For the reasons above, having another test at that time is optional; the chance you were infected is near zero, from a statistical standpoint. But feel free to do it if the additional negative result will help you stop worrying about it.

I hope this information is helpful. Let me know if anything isn't clear.

HHH, MD

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45 months ago
Dr Handsfield,

Thank you for your very quick response even though the hour was late.  Your answer gave me a very big peace of mind. I just submitted the question because the tester at the county's health department where I took the test told me that it is 97% accurate after 3 months, so that got a little bit worried.  Maybe it's the legal conservatism but I just wanted to make sure. 
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
45 months ago
The Determine test indeed may be slightly more prone than other tests to give false negative results between 6 weeks and 3 months. But my guess is that indeed the health department's reasoning is more "legal conservatism" than specific awareness of Determine's performance. In any case, even if you assume "only" 97% test sensitivity, your results basically prove you weren't infected. If the odds of catching HIV are only 1 in 10,000 for each exposure, then after a 97% reliable test the chance you have HIV becomes 3 in a million. That's low enough to be considered zero for all practical purposes.

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45 months ago
I should be optimistic though right? The test being negative is highly encouraging from your point of view and  the odds from what you describe are astronomically in my favor. It's just that I want to put this behind me because I can"t focus on my goals that I have for my life. Should I just move on and forget about it? 
45 months ago
Doctor?
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
45 months ago
Sorry I missed this earlier.

You correctly understand why you definitely should be optimistic. I'm sure you don't have HIV and any other tests you do will remain negative. If I were you, I wouldn't feel a need for further testing and would be having unprotected sex with my wife without worry. But it's up to you whether you will be able to "move on and forget about it" at this point, or might benefit from a truly 100% conclusive Determine test result at 3 months. 

That completes the two follow-up comments and replies inclueded in each question and so concludes this thread. I hope the discussion has been helpful. Best wishes and stay safe.
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