[Question #2710] HIV Window periods

42 months ago
Hello Doctors,

I was at it again by drunkenly bring home a csw :(. I'm beginning to seek treatment for alcohol issues that I may have. In this particular encounter, again I wore a condom throughout and received a blowjob, there was a brief moment when my partner started to insert my covered penis in her vagina and it lasted like 2 seconds before i withdrew and she continued to give me a blowjob. Now the morning after, I noticed that my toilet seat had what looked like little blood on it. The condom was intact throughout the act and i dont recall any actual blood on the condom on me in general. Anway, so I talked to my doctor about this and he was willing to bet the house that I didn't acquire anything from this act. I however plan to take an HIV test for peace of mind. I've taken a LabCorp 4th Generation antigen/antibody test with Reflex in the past. Is this test conclusive at 4 weeks?


H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
42 months ago
Welcome back to the forum. But sorry you found it necessary. Dr. Hook really answered this question in your previous recent thread. This was a different exposure but the cirumstances apparenly were the same:  only condom protected oral expsoure plus a very brief potential vaginal exposure. But condoms work. I agree with your doctor; I also would "bet the house" you didn't catch HIV or any other STD from this event. The large majority of female sex workers don't have HIV; oral sex is never a sigbificant risk for HIV; and when a woman has HIV, the average risk of transmission from a single episode of unprotected vaginal sex is around once for every 2,500 exposures. If you also factor in that you used a condom and the very brief penetration, there is simply no chance you caught HIV.

However, if you go ahead with testing, the 4th generation (antigen-antibody) test is the right one to have. However, it is not quite conclusive at 4 weeks; you should wait until 6 weeks after the event for a definitive result. In the meantime, stay relaxed. There is no chance of a positive result, assuming this exposure and the one you described in your other thread are your only possible exposures.

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

HHH, MD

---
42 months ago
Thanks a lot for your response doctor, very reassuring. These are the only 2 exposures I've had in past 4-5 months. I suppose it's more the guilt and the regret of the actual acts that's driving my anxiety and clouding the rational side of my brain :(. And certainly perusing a lot of posts on medhelp and here doesn't help!

So I have a follow up question, I've noticed that answers to conclusivity of different 4th Gen HIV tests have ranged from 4-8 weeks. Has the consensus changed over time or are there certain 4th gen tests that are conclusive earlier?

"average risk of transmission from a single episode of unprotected vaginal sex is around once for every 2,500 exposures. If you also factor in that you used a condom and the very brief penetration, there is simply no chance you caught HIV."

This is for just general education about this, but does me being uncircumcised change this?  Also does the length of time one is penetrating also matter?

Thanks a lot again Doctor, this shall be last of my anxiety ridden posts here. I'll try not to take up your valuable time and waste medical resources ever again!
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
42 months ago
On this forum, we used to advise 4 weeks for conclusive results with the 4th generation tests, but switched to 6 weeks a couple of months ago. We became aware of a systematic review of the published literature and learned that there is a very small percentage of situations (1-2%) in which it takes up to 6 weeks.

Being uncircumcised roughly doubles the risk of sexual acquisition of HIV. "Doubles" sounds like a lot, but it really isn't. If we assume a 1% chance your partner had HIV, 1 chance in 2,500 of transmission if she had it, and reduce that risk by 99% because you used a condom and had very brief penetration, the chance you caught HIV would be 0.01 x 0.0004 x 0.01 = 0.00000004. That's 4 in 100 million, or 1 in 25 million. If we double that risk because you are uncircumcised, your chance of being infected was 1 in 12.5 million. Still zero for all practical purposes.

Thanks for your kind words about our services. I hope this analysis also has helped.
---