[Question #4533] Oral Sex Exposure

29 months ago
Hello Drs:

I’ve spent some time researching other questions on the site, and I feel quite educated reading previous responses.  Nonetheless, I thought it was worth getting your opinion on my situation.

Bisexual married man.  On October 16th, I received unprotected oral sex from another male w/ ejaculation.  No anal or any other form of contact was had.  I’m not certain of the other individual’s STI status, but have no reason to believe he was infected with anything.  The individual claims to be on “Prep” for HIV prevention, so that provided some reassurance that he has professional medical care and is generally conscious about STIs.

Almost 4 weeks later (November 11th), I began experiencing some urinary symptoms, but not certain they’re at all related to my encounter.  I even noticed, on a single occasion, a small amount of staining in my underwear, but honestly, it’s entirely possible it was normal secretion of semen from a previous ejaculation.  I also have some burning sensation when having a bowel movement.  In addition, in my professional life, I’m in a time of change, so my stress level from normal life has been elevated in recent days. 

1.  Does a 4 week lapse in time between the event and onset of symptoms make any sense for any of the possible STIs that can be caught via receipt of oral sex?

2.  I’ve read repeatedly on this forum that chlamydia doesn’t transmit from throat to penis, but I’m curious if there are any statistical data on this.

3.  I’ve also read on this forum that gonorrhea almost certainly results in actual discharge, and I think the 4 week timing would not suggest this is as a possible cause.

Just looking for your professional insight on my situation.

Thank you.
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
29 months ago
Welcome. Thanks for your question, your confidence in our services, and for researching other questions similar to your own. We love knowledgeable, thoughtful questions like yours. They indicate you pretty well understand the issues already and probably have predicted my responses. You correctly understand that this was a low risk exposure. I think my responses will contribute to further reduction of the stress you are experiencing. I'm providing a somewhat lengthy, blog-like reply that I can re-use for future similar questions.

You don't ask specifically about HIV, but your partner being on PrEP not only protects him from HIV, and effectively documents he doesn't have HIV himself. But it also means that if he really did have HIV, it would not be not transmissible to his partners. As for your symptoms, I agree they are not suggestive of any STI from the exposure on your mind. Certainly anal itching or irritaiton cannot result from an oral sex exposure.

1. Yes. Any symptoms due to STIs from this exposure would have shown up within 2-3 weeks, usually within 5 days (gonorrhea, herpes) or 10-14 days (chlamydia, nongonococcal urethritis [NGU]).

2. There are a handful of studies on chlamydia transmission by oral sex, two of which are the most commonly cited. I am the senior author on one of them. We and other investigators showed that among men who have sex with men (MSM) attending STD clinics and diagnosed with NGU, chlamydia was the cause in 20-40% of those whose sexual exposures in the preceding weeks included insertive anal sex. In men whose only recent exposures were insertive oral sex, none had chlamdia. There also are longstanding data showing oral (throat) chlamydia to be rare, even in MSM who frequently perform oral sex on multiple partners. These results were with culture, which misses some infection detected with the newer nucleic acid amplification tests (NAATs). But even with NAAT, oral infection is rare (positive in 1-2% of MSM, versus 10-40% urethral and rectal), so there's just not much opportunity for oral to genital transmission.

These data don't mean oral to penile chlamydia transmission never happens. If hundreds instead of fewer MSM were studied in the same fashion, I'm sure some would have chlamydia despite having only oral and never anal sex. But for sure it's very rare. And by the way, in contrast to chlamydia, urethral gonorrhea is common in MSM in whom fellatio was the only recent exposure.

3. As for asymptomatic gonorrhea, here too I'm one of the international mavens. One of the most cited papers I ever wrote, very early in my career, still stands as the main published research on asymptomatic urethral gonorrhea in men. Although we found it to be quite common, it was still a small minority of all gonorrhea. More important, we now know -- we didn't at the time -- that particular strains of Neisseria gonorrhoeae are especially likely to cause asymptomatic infection and were especially common in those years. Those strains now are rare. And further to the point, such N gonorrhoeae strains always were rarer in MSM than in straight men. (I won't go into the biological reasons for that, but it's well decumented.) So although asymptomatic infection can happen, at present it probably accounts for <1% of all urethral gonorrhea. In other words, >99% of infected men develop obvious symptoms, usually within 2-3 days and almost always within 5 days of exposure. So with no obvious symptoms (dripping pus, painful urination) there is no realistic chance you have gonorrhea.

Can I give a 100% guarantee? No. But if I were in your situation, I would not feel a need for testing and I would continue unprotected sex with my wife without worry -- indeed, would have done so after a week or so with no symptoms.

I hope this information is helpful. Let me know if anything isn't clear. In case you're interested, below are links to the two studies cited above.



29 months ago
Thank you Dr. H for your thorough reply to my questions, and I’ll certainly take a look at the links provided.

As a follow-up, I’ve also seen reference on this forum to “Chronic Pelvic Pain Syndrome” / prostatitis.  Through this reading it’s clear that these are not directly related to sexual activity, but may present symptoms that are similar and may be brought on by stress / anxiety.  Do you have any recommended reading from reputable sources on these topics?  Obviously a discussion for me to have with my doctor should symptoms persist, but figured I could at least educate myself before that conversation. 

Finally, just want to confirm that should my symptoms (unlikely, I realize) be the result of non-chlamydial NGU, this is not anything that would transmit male to female through normal sexual intercourse.

Thanks again.  This forum is a fantastic resource.

H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
29 months ago
The main symptom of CPPS, and prostatitis, is pain -- usually a fairly vague pain involving the lower abdomen, testicles, sometimes rectal area. Nothing you described seems to imply CPPS. But if you'd like to read more about it, just google the term (spell it out). Last time I looked, the Wikipedia article was good. There's also excellent information from the Stanford University department of urology.

The transmissibility and potential harm to partners from nonchlamydial NGU acquired by oral sex hasn't been studied, but no information or clinical expoerience suggests there is a significan risk to partners.