[Question #2611] HIV test

96 months ago

Hello Doctors, I've had two HIV test, one at 28 days after exposure and another at 35 days after exposure, one was a rapid 4th gen blood test and the other was a 4th gen lab blood test performed by lab corp, both of the results came back negative, I am having trouble accepting my results. Do I need to test again ?

H. Hunter Handsfield, MD

96 months ago

Welcome to the forum. Thanks for your succinct question. My reply is similar.

The HIV antigen-antibody ("duo", "4th generation") blood tests, both rapid and lab-based, are almost always positive (>95%) by 4 weeks, but in rare cases take 6 weeks to reach 100% reliability. With two negative results at 4 and 5 weeks, almost certainly you were not infected, but you may want to have another test at 6+ weeks. If that result is negative, as it probably will be, for sure you can stop worrying.

If you would like to add some information about the nature of the exposure, I might be able to provide additional advice.

I hope this information is helpful. Let me know if anything isn't clear. Best wishes and stay safe--

HHH, MD

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96 months ago

Thank you, the exposure was unprotected sex with an unknown woman, should I get tested for herpes also ? I haven't had any blisters or sores appear on my genitals since contact and it had been two months since exposure. I do not know of this woman's condition in any way. It was a short brief sexual encounter through vaginal and oral only

H. Hunter Handsfield, MD

96 months ago

"Unknown woman" doesn't say much about the odds she has HIV, but on average under 1 in 1,000 women (in the US) have HIV; and a single episode of unprotected vaginal sex carries a risk of 1 in 2,500 if the woman is infected. Receiving oral sex is risk free.

Herpes is unlikely from any single exposure, especially with no symptoms to suggest it. Normally testing is not done on account of any particular exposure unless there are symptoms or if risk is particularly high, such as partner having a known active infection.

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96 months ago

I recieved a non reactive result on my 7 week 4th gen duo test from LabCorp can I move on now ? On top of this I had a negative duo test at 28 days and 35 days.

H. Hunter Handsfield, MD

96 months ago

As I said above, "...you may want to have another [4th generation, "duo"] test at 6+ weeks. If that result is negative, as it probably will be, for sure you can stop worrying." You definitely didn't catch HIV during the exposure a few weeks ago; no more testing is needed.

That completes the two follow-up questions and replies included with new question and so concludes this thread, which will be closed shortly. I hope the discussion has been helpful. Best wishes and stay safe.

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