[Question #787] HIV Risk after exposure to acute infected person

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96 months ago
Hello Doctor (Handsfield or Cook),

Close friend tested positive recently

1) Made out/deeply kissed with pimples on their mouth during acute phase (perhaps high viral load). Is this risk? Why?

2) How infectious is someone 2 or 3 days post infection?

3) Individual had a large cut on hand, scabbed. Shared bag of Oreos. Scab touched cookies/the inside of bag. If high viral load dry blood ends up in my mouth immediately after, is there risk? Why?

4) P24 duo - CDC says after 6 weeks is 95% accurate, you claim at 4 weeks it's 100% accurate. Found a few papers that reference a "2nd window period." Seems a very rare occurrence, however, these papers do exist. I hope you can elaborate on these specific papers, how often you feel it may occur and why, and this topic as a whole:
a) http://jcm.asm.org/content/52/11/4105.full.pdf
b) http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1248444/

4) I have noticed slight skepticism you have towards the RNA test in a clinical setting. Seems it's essential in preventing infection in blood donations though. At 4 weeks, like the P24 ab/ag test, is getting an RNA test along with antibody test just as accurate, if not more accurate since there doesn't seem to be a chance of a rare, yet seemingly existent "second window period?"

5) You've claimed new antibody tests are more sensitive than ones being used even a few years ago. Does Quest/LabCorp use these? Accurate to say most will be HIV+ by 50% @ 2 weeks, 95% @ 4 weeks, 99+% @ 6 weeks (or 8 weeks?)?
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Edward W. Hook M.D.
96 months ago

Welcome to the Forum.  I'll try to help although, as you might imagine, there are no solid scientific data on the risk of HIV exposure at a specified number of days following diagnosis or day-by-day data on HIV test performance.  You are asking for information that does not exist.  That said, from what you describe, despite your acquaintance's recent HIV infection, none of the activities you describe place you at ANY risk for HIV.  If you did not have sex or share needles with this person, you need not be concerned.  With this, on to your specific questions:

1.  Pimples make no difference, just as oral sores, gum disease or poor dentition make no difference.  HIV is not transmitted by kissing.  I base this statement on studies of thousands of exposed persons and the absence of any cases in which HIV has been shown to be transmitted in this way.

2.  It is unlikely that a person is infectious at all two days after an exposure that leads to HIV infection. The virus has not had a chance to grow to the high levels of viremia needed to transmit infection.

3.  Sorry, we are not in the business of reviewing specific papers.  You can choose if you wish to believe those sources or us.  Please remember that, as a government agency which takes the approach the they cannot ever "afford" to be wrong, their advice tends to be very (i.e. overly) conservative. 

4.  At 4 weeks the combination of an RNA test plus and antibody test is just as accurate as the combination of a p24 antigen test and an antibody test, just more expensive and less well tested.  If a so-called second window existed, the same things that would make a 4th generation test negative would also make the combination of an RNA and antibody test negative.

5.  Yes, Quest uses current, up to date tests.  Your estimates of performance are reasonable.

I hope these comments are helpful.  My sense is that you are overly concerned over what sounds like a no risk event and making your anxiety worse by searching the internet.  I suggest that you relax, move forward and stay off of the internet.  EWH

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96 months ago
That was incredibly prompt, thank you so much. I'm so sorry for misspelling your name as well.

1) I'm a bit confused as to how cuts or pimples make no difference. Theoretically, if blood were present (pretty sure it wasn't, but still), wouldn't that pose a risk? Why/why not?

2) You've claimed fingering even with a cut on the finger poses no risk. How is that no risk, but sex with a chafed penis, uncircumsized penis, or pre-existing STDs increases risk. I'm having trouble understanding how a wounded finger is no risk but a wounded penis is. Can you clarify how there's a difference?

3) Personal stories where exposure didn't lead to infection help a lot with putting perspective how difficult it is to contract. Do you know of, or have you had any personal/specific occupational exposures where infected blood got on a cut or got in one's mouth and person wasn't infected? I've read many stories on medhelp relating to exposure without infection sexually, but not much on occupational exposures (non-needle stick), especially when cuts are present.

4) I've read it's a 1 in 1000 chance of getting HIV from being insertive with a pos partner. Is this based off of an approximate viral load?

5) CDC says HIV found in dried blood is still infectious. My paranoia clearly has the best of me, but still I'd like to know if some of his scab got in my mouth if that would be potentially infectious and why or why not.

6) Is HIV 2 on the rise in the US and how greatly should it be of concern?
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Edward W. Hook M.D.
96 months ago

1.  Cuts and pimples (they are quite different) do not change risks as they are effectively sealed from the entry of material from a partner into the partner's body.  HIV must get deep into tissue to cause infection.  Further, if you think about it, with cuts and pimples, the direction of flow is out of the body, not into it.  for complicated scientific reasons beyond the scope of this site, sores of syphilis or herpes are different than cuts and pimples and may increase risk for acquisition of infection.

2.  See above. Further, these are facts, not "claims" - if you choose to not believe this, this is up to you but this is not a debate.  The anatomy of the skin of the finger is entirely different that the anatomy of the skin of the penis, just as the skin of an uncircumcised penis is different form the skin of a circumcised penis.

3.  There are literally thousands of instances in which occupational exposures of the sort you describe have not led to transmission of HIV.  this is not the place for such vignettes, nor do vignettes take the place of data and cumulative experience which is what our answers are based upon.

4.  HIV transmission/acquisition is complex and impacted by many facts including viral load.  the 1 in 1000 estimate is an accurate general estimate,  many factors, including higher viral loads are associated with modest, does-related increase in risk of infection transmission.

5.  Again, tis is not a debate. CDC is very conservative.  There are no data regarding infectious HIV in dried blood but the CDC's recommendations appropriately reflect an abundance of caution..  Further, because of the nature of host defenses in the oral cavity and gastrointestinal tract, ingestion of HIV is not thought to be infectious. This is the reason that performance of oral sex on an infected partner is far less infectious than for genital exposure. 

6.  HIV-2 remains rare globally, being primarily limited to Western Africa.  Current tests for HIV do detect HIV-2 and well as HIV-1.  I would not be concerned about it.