[Question #854] Risk Assessment

75 months ago
Hi Dr,
I'm a bisexual man, and had my first gay experience in 15 years 2 days ago.
During the encounter, there was mutual (unprotected) oral. I received protected anal  for 3-4 minutes (I did not inspect the condom, but it looked intact after he pulled out), and I received anal fingering and analingus. Neither of us ejaculated during the encounter.
I asked him after the encounter (stupid, I know) about his disease status, and he said he is checked twice a year when he has his physical.
I've been doing some homework on the topic, and although the general risk seems low, I was alarmed by the increase in virulence that the acute stage of HIV poses (up to 26 times increased risk).
I know the chances that I've contracted HIV are low, but I feel paranoid and a little frantic.

1. He said he is checked twice a year at his physical, but I've heard most standard physicals don't include tests for stds. Does the bloodwork done at a standard physical test for things like HIV?

2. I had a very small cut in my upper gum from accidentally hitting it with the head of my toothbrush. Should I be worried about the increased risk of the oral, even though there was no ejaculation?

3. Based on what I've read, if he was infected (especially if he was in the acute stage), even with an intact condom my chances of contracting the virus could be as high as 1 in 30. Can you give me some measure of the probability that I've contracted HIV?

4. At 4 weeks, with a 3rd gen test, how accurate will my test results be?

H. Hunter Handsfield, MD
75 months ago
Welcome to the forum. Thanks for an articulate, insightful question.

My first comment is to congratulate you on having safe sex in this situation. My second responds to your "stupid, I know" comment, which I think refers to asking about HIV status after instead of before the encounter. Indeed, it is always wise to ask beforehand, and in the long run safer. Most people are not knowing untruthful about HIV status when asked directly, and if he had said he is infected (and not on treatment with a low viral load), it would have been best to avoid anal sex entirely, even with a condom. However, a condom was used; almost certainly he is HIV negative; oral sex is very close to zero risk; and fingering is free of all risk. So all things considered, there was little HIV risk from this encounter, and not much chance of other STDs either. To your numbered questions:

1) I would bet that he intended to imply that HIV testing was included when he said he is "checked" twice yearly, and if blood tests were included, probably syphilis testing. Harder to know about other STDs. Urine testing for gonorrhea/chlamydia doesn't detect oral or rectal infection; and blood tests may or may not have been done for viral hepatitis and HSV; and there are no useful tests for HPV infection.

2) One estimate of the risk of HIV from fellatio, penis to mouth, is one transmission for every 10,000 exposure to infected partners. That's equivalent to giving BJs to infected men once daily for 27 years before infection might be considered likely. And obviously, at any point in time, lots of people have oral sores of various kinds. All things considered, that probably does not materially increase the very low risk of HIV infection.

3) It is true that HIV is most transmissible during the acute infection, before blood tests become positive. However, from a statistical standpoint, the chance any particular person is at that stage is very low. And I would point out that even at 26x increased risk, the transmission rate would become once for every 370 exposures instead of 1 in 10,000. (Or, by extrapolation, BJs on infected men for a year.) And these odds are generally assumed to apply to exposures with ejaculation in the mouth, so your risk is lower still. No matter how you slice it, the odds remain very strongly in your favor.

4) I would recommend a 4th generation test (i.e. combined antigen-antibody) rather than 3rd generation (antibody only). The 4th gen tests are 100% conclusive at 4 weeks; 3rd gen probably ~95%. If you are interested in other STD tests, consider a syphilis blood test at 6 weeks; and urine and anal swab tests for gonorrhea and chlamydia (these can be done at any time); and throat swab for gonorrhea (chlamydia is too rare in the oral cavity to warrant testing). However, in the absence of symptoms, the chance any of these will be positive is very low, although of course not quite zero.

I hope this information has been helpful. Best wishes and stay safe--  HHH, MD

75 months ago
Thank you for your reply Dr. Handsfield.
As I stated before, I assumed my risk was quite low, but am still feeling nervous/paranoid and felt the need for reassurance.
My 1 follow-up question would be your thoughts on the efficacy of an intact condom?
Close to 100%?
H. Hunter Handsfield, MD
75 months ago
An intact condom indeed is 100% protective, assuming it is properly used, i.e. in place before any penetration, and that it does not break wide open. If the head of your penis was covered, protection was complete.

74 months ago
Hello Dr. Handsfield.
An update on my situation: 
I took an RNA test at 11 days (negative), and today I took a finger-prick rapid test (did not think to ask specifically what generation test was used) at 47 days, which also came back negative.
Obviously, I was quite happy with my results.
Should I take the combination of these 2 test results as definitive proof with no need for follow-up tests?
As this will be my last reply, just wanted to say thanks for the help, your comments did a great deal to ease my nerves :)

H. Hunter Handsfield, MD
74 months ago
You are justified in being happy with the test results: the combination of your two tests is 100% conclusive. Some experts would still recommend an antibody test at 3 months, but that's basically from an excess of caution. It isn't necessary and I don't recommend it. But some people feel better following conservative recommendations, so it's up to you.

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