[Question #203] HPV transmission risk one brief incident

97 months ago
Hello Dr.

I would like to address this question to Dr. Hook - he helped me last time.  Please see my question "complex STD question." for more information on this incident.

Six months ago, I had brief, unprotected, insertive sex with an unknown partner that lasted between 5 and 10 seconds.  It was dark and I literally don't know if it was a man or a woman, but I suspect it was a man.  I am a 34 year old man.  The incident lasted between 5 and 10 seconds.  I have conclusively tested negative for all STDs.  I am now concerned that I contracted HPV and passed it to my girlfriend.  I have read that HPV rates are extremely high rectally in men.  I have also read conflicting information on the per-incident transmission rates for HPV.  Some say as high as 60%, some say as low as 5%.  I have a sinking feeling that I caught HPV, transmitted it to my partner, and it will show up on her next pap because she is over 30 and will likely have an HPV test.  We have been together for a little over one year.  

I know that HPV is "nothing to worry about" and that I have likely been exposed to it before, but I still fear I contracted it.

My question

(1) what is the likelihood that I contracted HPV from a 5 to 10 second exposure.  I assume there was a high probability my partner had HPV.

H. Hunter Handsfield, MD
97 months ago
Welcome back to the forum and thanks for your question. Dr. Hook and I take questions in turn or randomly, depending on who is available. The forum home page clearly states that we do not honor requests for one of us or the other. Dr. Hook and I have been close colleagues and friends for 3 decades and although our styles differ, our expertise is identical and our opinions and advice virtually never are significantly different from one another.

FYI, I reviewed your discussion with Dr. Hook 2 weeks ago and agree entirely with his evaluation and advice.

As for this question, you leave out a rather important detail:  Was the exposure oral, anal, or vaginal? On one hand, I find it difficult to believe you didn't know whether your partner male or female, no matter how dark it was. OTOH, I guess I can imagine oral sex with a partner whose sex you don't know, but certainly not vaginal or anal. Since you "suspect" a male partner, I would assume that to be true; and I am also deducing it was oral sex, i.e. you received a BJ, right? If so, there is little risk of HPV, which is transmitted rarely by oral sex.

So we can discount your "sinking feeling". There was little likelihood your partner had an oral HPV infection, and even if he did, little if any risk you acquired. I don't know where you read either 5% or 60% for the per-transmission risk of HPV. I am unaware of any data whatsoever on this. Even if such figures were accurate, they would only apply to vaginal or anal intercourse, not oral sex. Even if we assume the worst -- that your partner did have HPV -- you can never know with certainty whether you were infected. But even if you did, it truly doesn't matter. Your chance of having a genital HPV infection is not appreciably higher on account of this particular event than it was before the exposure; and your partner's chance of someday having an abnormal pap smear also is no higher. (This would be true even if your exposure was unprotected vaginal or anal, and even if we assume a 50% chance your partner had HPV.) There would also be no way to know, and no reason even to suspect, that it could be traced back to any particular exposure either of you had in the past.

FYI, if you had told Dr. Hook the details of this exposure -- that it was oral and probably with a male partner -- his replies would have been even more reassuring. For example, chlamydia is rarely transmitted by oral sex.

The bottom line is that you can go forward with complete confidence you have neither HPV nor any other STD from the event of last April.

I hope this has helped. Best wishes--  HHH, MD

97 months ago
Thank you Dr. Handsfield, 

I appreciate your response, thank you very much.  

Allow me to clarify:  I am almost certain my partner was a man.  Also, the intercourse was not oral but rather unprotected anal.  I apologize for being unclear in my original question, my intention was not to withhold valuable information.  

So, my follow up question is this:

(1) Assuming a 5 - 10 second unprotected insertive anal exposure, can you give me a ballpark estimate of my having contracted HPV?  I have conclusively tested negative for all other possible viral and bacterial STDs for which there are available tests.

Again, thank you for your help - sorry for the confusion.
H. Hunter Handsfield, MD
97 months ago
OK, that clarifies things a bit. The sort of male partner who would have casual anal sex in this manner probably has somewhere around a 50% chance of having anal HPV. As noted above, there are no data to estimate the per-exposure transmission risk, but I given the brevity of exposure, I would guess no higher than 1%, and certainly no higher than 5% (1 in 20). But please also read the other advice in my reply above:  even if we assume the worst case scenario, that you acquired HPV, the chance your partner will someday have an abnormal pap smear as a result is a) very low and b) not traceable to any particular partner she had any time in her life, and c) certainly not traceable to any particular exposure you have had, whether last April or any other time.

I note that nothing was said about HIV or syphilis in your thread with Dr. Hook. As you may know, unprotected anal with an anonymous or casual male partner is the highest risk for HIV and syphilis of any kind of sexual exposure. Most likely you were tested for them, but if not, do so now. Both of course are far more dangerous than HPV, which is trivial in comparison. Most syphilis would have been prevented by having take azithromycin, as for gonorrhea and chlamydia. However, a large proportion of syphilis in gay men in the US is resistant to azithromycin. The chance you would have been infected from such a brief exposure was low, but better safe than sorry.

Finally, for goodness' sake, if such an event or opportunity arises in the future, use a condom!

97 months ago
Thank you Dr. Handsfield,

I have tested negative for syphilis, gonorrhea, chlamydia, HIV, and Hep B.  April was a difficult time, I was engaged in drug use and risky, impulsive behavior.  The incident was a wake up call.  I have been sober ever since and have been going to therapy.

This brings me to my final question regarding an oral sex incident I had 2.5 - 3 weeks prior to my anal sex incident.  I apologize for not putting all of my questions in one post, but I am nervous and I ask for your patience.

3 weeks prior to the unprotected anal incident, I got a BJ from a random guy.  I didn't think it was a problem because (1) I never had symptoms after the BJ, and (2) I had my mega dose of zythro and amoxicillin 3 weeks post-BJ (amoxicillin and zithro).  After the antibiotics, I tested negative for chlamydia and gonorrhea immediately, and again negative for syphilis, chlamydia, and gonorrhea 3 months later.  I know that insertive oral is low risk for most STDS, but just to be sure:

(1) What is the likelihood, in the absence of symptoms, that I contracted syphilis or gonorrhea from the BJ?  I had no chancre or discharge.

(2) If I did somehow contract syphilis from the BJ, am I correct in assuming I was not contagious in the absence of a chancre?

(3) What is the likelihood that, were I infected with Syphilis from the BJ, I transmitted it to my girlfriend in the 3 week window prior to the antibiotics?  Would this be unlikely given the lack of a chancre? Keep in mind that I tested negative for syphilis 3 months post exposure.

This will wrap it up for me, thank you for your help.

H. Hunter Handsfield, MD
97 months ago
I'm glad to hear your life is getting on a healther path, from all perspectives, and certainly hope the "wake up call" sticks with you.

1) The chance of infection from a single oral sex exposure is low, and as discussed previously with Dr. Hook and to some extent above, the antibiotics would have aborted any incubating syphilis if you had been infected.

2,3) In general, syphilis is not infectious for partners until a chancre develops. There may be exceptions, but all things considered, the chance you had any infection and exposed your wife is very low. Testing of partners is not recommended except in the face of proved infection, not merely on account of high risk exposures.

Thanks again for your confidence in our services. Best wishes and stay safe!.