[Question #12479] gay - oral sex

7 months ago

I’d like to ask about the risk of HIV transmission through oral sex. A few days ago, I had unprotected oral sex (both giving and receiving) with a man who ejaculated into my mouth. I spat out the semen without swallowing, didn’t brush my teeth beforehand, have no oral injuries, and maintain good oral hygiene.Afterward, I rinsed my mouth with water, urinated, and showered. I had also fully recovered from bacterial tonsillitis about a week earlier. Since I didn’t know my partner’s STD status, I contacted an infectious disease center. They informed me that the risk of HIV transmission through oral sex is nearly zero and that PEP isn’t typically recommended in such cases.Could you please confirm if this information is accurate and if the risk is truly negligible?

Edward W. Hook M.D.

7 months ago

Welcome to our Forum. Thanks for your questions. I'll be glad to comment.

I agree with the message you received from the infectious diseases center. If you had been seen in my clinic, we would not have prescribed PEP for you. The risk for acquiring HIV from oral sex is simply too low to warrant PEP. It is statistically unlikely that your partner had HIV (most pen who have sex with men do not) and there has never been a case of HIV acquired from receipt of oral sex from an infected partner. As for participating in oral sex on an untreated HIV infected person, the risk is tiny- estimated to be on average less than 1 infection occurring for every 10,000 acts of fellatio. I would not worry about this exposure and do not see a compelling reason for testing related to the episode you describe although I understand that you may choose for the reassurance that a negative test provides. Should you choose to test, I am confident the test will show that you were not infected.

I would also suggest that for future casual encounters, that it is a good idea to ask your partner if they have HIV and when they were last tested. Most people do tell the truth.

I hope that this information is helpful. Please don't worry. EWH

---

7 months ago

Dear Dr. Hook, thank you for ur time. In December, I had STD testing five weeks after an oral-only exposure. Results were negative, but the S_Syphilis (anti-TP) value was 0.16. Could this indicate early infection or just a lab variation?

Edward W. Hook M.D.

7 months ago

The results of the syphilis test you describe reflect the normal negative result in syphilis tests. I encourage you to believe the result. There is no evidence that you have syphilis. EWH---

7 months ago

Dear Dr. Hook,Thank you for your response and reassurance. I truly appreciate your time and expertise. I have three final follow-up questions: Why does the syphilis test result show a value at all? Shouldn’t it be zero if there’s no infection? Is five weeks after exposure sufficient for reliable syphilis testing, or should I retest later for a definitive result? Is the risk of syphilis transmission through oral sex considered high?

Edward W. Hook M.D.

7 months ago

1. Why does the syphilis test result show a value at all? Shouldn’t it be zero if there’s no infection?

For all tests there is a negative range which is always expressed as a number. If the value were zero I would question if the test was working correctly. Believe your test results

2. Is five weeks after exposure sufficient for reliable syphilis testing, or should I retest later for a definitive result?

To be absolutely reliable testing would have been better at 6 weeks HOWEVER, the amoxicillin-clavulanic acid you took would have prevented/cured syphilis entirely in the unlikely event that you had been exposed. Once again, I urge you to have confidence in your test results.

3. Is the risk of syphilis transmission through oral sex considered high?

No. First, among STIs, syphilis is a relatively rare disease- other STIs such as gonorrhea or chlamydia are much, much more common. Second- most single exposures do not result in infection. Third, transmission of syphilis through oral sex, while it can occur is, overall, relatively uncommon

I hope the information I have provided has been helpful. This thread will now be closed. There should be no reason to return regarding this encounter or your test results. EWH

---