[Question #25] Interesting question...

101 months ago
Good afternoon Dr. Handsfield,

My name is Jeff and I work in the mental health field. For a while now, I have been offering adolescents and young adults the chance to ask me questions (either personally or privately) in order to help guide them through difficult times. Now, I'm no expert so I remind my clients that I act more as a "broker" than anything else. For specific questions that lay outside of my domain of knowledge, I'll go to the experts themselves and get the best advice. Usually, I'll get several because I teach my clients the importance of examining a wide range of evidence with sound critical judgement.

One question was submitted to me two days ago and I found it interesting for it's level of complexity. One young man asked me a question about STD/STI transmission...now, normally, I offer pamphlets and literature secured from CDC and even download the facts sheet off of ASHA here....they've done well with getting the information out there....but this one had me stumped.

His question is written almost verbatim below: 
"So...let's say I'm with a chick, and she's kind of 'sketchy'....you know what I mean. And I don't do nothing with her, like, I don't kiss her or touch her down there or whatever, but let's say she touches ME....now I know masturbation isn't something that can't transmit diseases and stuff, but let's say this chick spits on her hand to get me off...can THAT spread anything? Can I get herpes or whatever if SHE'S got them and uses her spit on me?

Another thing....what if this happens, right? And I wash my stuff IMMEDIATELY after...like five minutes or so....with antibacterial soap? Does that stop it?"

I thought this was a pretty sophisticated question, (despite the content lol), and can't really answer him. On the one hand, logically, it would seem possible that saliva would be able to transmit herpes or some form of STD/STI. If you can get it ORALLY, then yes, saliva exists in the mouth and like all bodily fluids, has to carry these pathogens. So I called the CDC and asked them and the man I spoke to seemed equally stumped and had me submit the question for a call-back. I received one and the woman explained to me that it was possible, yes, theoretically, to spread an STD/STI, notably, herpes, vis a vis saliva. She also followed up with the odds being low that the disease WOULD be spread. She admitted herself that this was a tough question. In short, the answer seems to be a yes...but a theoretical one and one with low probability. 

Now, I went and watched the herpes video you have under the STDs/STIs header of the website and it explains that oral herpes, HSV1, CAN be transmitted to the genitals, but that the outbreak would be limited in severity and even more limited in recurrence. However, I would like your opinion on this question as well. Now bear in mind I don't know if this young man is speaking of a particular person he KNOWS, a sexual service individual (like a massage parlor worker), a stripper.....he didn't specify. He just used the adjective "sketchy" which suggests to me any of the above. Bottom line, what can I tell the young man? If STDs/STIs CAN be transmitted via saliva as a lubricant from said "sketchy" individual, where would he,(or anyone really), fall within the "odds are" category? What is the chances they can walk away with an infection and would it be as severe as if it were a direct mouth to genital contact? Does his "washing right away" scenario decrease this risk, if any?

Thank you very much for your time and consideration, and all that you and others at ASHA have done to promote this information to the public!


Jeff M. LMHC
H. Hunter Handsfield, MD
101 months ago

Welcome to Ask the Expert. Thanks for your question.

There are no data to document the precise risk of STDs in this circumstance. But busy STD clinics see few if any patients with STDs whose only contact was the sort described by your patient. In my 40 year career in the STD business, I have never seen a patient with a documented STD, or heard of one in my clinic, whose only possible exposure was hand-genital contact. Not one. That doesn’t prove it can’t happen, but certainly it is exceedingly rare if it happens at all. And the known biology of STD bacteria and viruses would not suggest a risk. Few if any STDs are transmitted by saliva. Some of them – HIV, for one – are killed by saliva, probably one reason why kissing and oral sex rarely if ever transmit HIV. Or STDs.

To the specific exposure, the only infection that would be a conceivable risk is herpes due to HSV1, the main cause of oral herpes. But transmitting HSV is believed to generally require massage of the virus into tissues, not just exposure to saliva or other infected fluids. That’s why initial genital herpes almost always shows up at the sites of maximum friction during sex:  penis head or shaft, labia and vaginal opening in women, etc. In any case, the amount of virus in saliva must be extremely low, even in people with active herpes outbreaks.

Medically untrained persons tend to assume that exposure to just one bacteria or virus particle is sufficient for transmission. Not true. Almost all infections have thresholds of the number of infectious particles and the tissues to which they must be exposed. The very reason STDs are transmitted by sex is that the causative agents evolved – in parallel with human evolution – to be hard to transmit except by large numbers with especially intense, intimate contact with moist genital tissues.

 As for washing soon after sex, it can’t hurt and might slightly reduce the risk of catching anything. But when the risk is as miniscule as in the exposures described, it probably makes no meaningful difference.

 When patients are anxious about STD transmission by means other than intercourse or oral sex, they can be counseled to ignore both the biology of infection and transmission (e.g., whether herpes or HIV can survive in saliva or on contaminated surfaces) and to disregard whether infection CAN occur. Instead, emphasize that it DOESN'T occur; i.e. transmission in such circumstances is rare if it occurs at all; the biological reasons don’t matter. Someone with the kinds of exposures you have described definitely should not be tested for STDs in the absence of symptoms, and in general need not take precautions against transmission to their regular partners. Worrying about one in a million risks – even if we can’t prove they are zero – usually is an exercise in frustration and futility.

My final comment concerns a “sketchy" female partner. Or male partner, for that matter. When the concern is STDs from the mouth, the frequency of infection – oral herpes in particular – is no higher in persons with a hundred or a thousand lifetime partners than those with only one or no past partners.

I hope that helps. Take care.