[Question #12478] Quick Clarification

10 months ago

Good Afternoon,

I had a quick question concerning another referenced answer. In question 9885 Dr. Hook stated that any negative 4th gen test beyond an exposure rules out the possibility of exposure. I was under the impression there was still a possibility, though quite remote. For instance, if you have a potential exposure and your partner tests a week later and is negative on a 4th gen test, is that really all the assurance one needs?

Thanks so much!

H. Hunter Handsfield, MD

10 months ago

Welcome back, but I'm afraid you misread that question. 9885 was about gonorrhea testing, not HIV. As Dr. Hook said, 4-5 days is plenty of time for gonorrhea.

HHH, MD

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10 months ago

Hey Doc,

Not trying to be a pain, but I wanted to verify what I'd read. That question was speaking to HIV directly:

"A few additional comments for future reference:

Condoms break about 1% of the time. Breakage rates are higher with rectal intercourse.

When a partner has a negative 4th generation test any time beyond a sexual encounter, they cannot have transmitted HIV."

Thats the statement I was looking for clarification on.

H. Hunter Handsfield, MD

10 months ago

You're right about that statement, which I missed previously. But you're ignoring that just before then, Dr. Hook wrote "4th generation tests for HIV are 99% conclusive at 4 weeks and entirely conclusive at 6 weeks - when combined with a negative HIV RNSA test, tests are conclusive any time more than 4 weeks after an exposure." The later statement you quote obviously was a quick statement of reassurance, not intended to override his main message. This is also a good example why users should depend on the replies we give to their own questions and not look for others addressing the same topic; the wording of our replies often varies with the particular question and the user's circumstances.---

H. Hunter Handsfield, MD

10 months ago

And it's true that people without detectable HIV p24 antigen (the Ag component of the 4th generation test) and those with negative PCR/RNA tests cannot transmit the virus. A negative test in a partner following exposure proves no HIV exposure occurred.---