HPV-16 transmission pathway and odds

[detroit_traveler]

A young adult male (clean of all STI's) has 30 min of vaginal sex (with a condom) with a female who has had hundreds (perhaps even >1000) of sexual partners. The male has heavy oral contact with the female's body, including her breasts/nipples, but excluding her face, anal region, and vaginal region. During two 5 min segments of the act, the female touches the male's uncircumcised penis (she had touched her vagina at some time prior to that). For 1-2 min, the female interacts orally with the penis of the male (95% confidence that condom was on; 5% that it was not). Four days after the act, the male detects red spots on his upper thigh/groin (indicative of an infection from a non-carcinogenic HPV strain).

Important:
1. Assuming the female is HPV-16+ with 100% certainty, what is the (very rough) order-of-magnitude-ballpark probability of transmission of HPV-16 to the male during the act described above: 50%+, 5%, or 0.1%??
2. Where  does HPV-16 tend to settle down in the host's body: the mouth region, anywhere on the body, or just the genital region?
3. What other dangerous STI's should be a concern to the male; how strongly do you recommend that the male do a screening; what kind of screening; and after what period has elapsed?

Unimportant (any number of these can be skipped):
4. Is it true that a male who is HPV-16+ has approx. 6 to 1 odds of developping HPV-16+ oropharynx cancer?
[Fraction of US population diagnosed with HPV+ oropharyngeal cancer per year]/[Fraction of US population infected with HPV-16] = 0.224%/1.3%* ~ 0.17
5. Person C had been infected with HPV two years ago, but he is one of the lucky 90% whose immune system took care of it. Is Person C now considered "clean" when it comes to intercourse with another person?
6. Follow-up to  Question 3. form above: Does the expected benefit of the screening offset the potential individual health insurance impact (denial after a preexisting condition is divulged)?

[Edward W Hook, MD]

This thread seems to go on and on so this will need to be the final response.  With regard to risk for HIV, for a man, the highest risk exposure is rectal intercourse, followed by vaginal intercourse.  there are no proven cases of HIV transmission which have occurred with kissing (deep or otherwise), cunnilingus, or oral rectal sex.  Properly used condoms, if they do not break, (which occurs 1% of the time) transform sexual exposure with any risk to no risk.  

The risk for other mucosal STDs is similar.  Diseases with lesions are transmitted by direct contact with lesions and lesion sites.  

You need to relax, practice safe sex and move forward.  there will be no further answers to this thread.  EWH

[detroit_traveler]

This is only from the perspective of risk to the male.

Also, I forgot to insert "Unprotected oral-to-anal (male on female)" between 2. and 3.

[detroit_traveler]

Do you agree with the following danger ranking of a clean male performing acts on an infected female (worst risk to lowest risk):

1. Unprotected anal
2. Unprotected vaginal
3. Unprotected oral (male on female)
4. Unprotected oral (female on male)
5. Deep mouth-to-mouth kissing
6. Protected anal
7. Protected vaginal
8. Mouth-to-breast kissing
9. Protected oral (male on female, and female on male)

with the Top2 being the only truly dangerous ones.

[Edward W Hook, MD]

No, protected sex of any sort is safer than unprotected sex.  

I would endorse you getting the HPV vaccine. Even if you had one HPV type, there are 4 covered in the vaccine. Clearly you are worried about this and the vaccine is both safe and highly effective. EWH

[detroit_traveler]

Is giving & receiving unprotected oral sex safer than protected vaginal sex with a woman?

Thanks again for sharing your knowledge. I will get a screening done after about six months and I might get some Gardasil injections while I still can (since it's unknown where Type 16 HPV enters the body, I'd rather not gamble without an edge).

[Edward W Hook, MD]

If you will be seeing  the same partner repeatedly, the best thing you can do is to both be checked at the same time for STDs.  If both have negative tests, there is no concern for STD transmission.  Beyond that, conoms are the best thing to do, particularly if your partner will continue to have other partners.  

We recommend periodic STD "screening (testing in the absence of symptoms) if you have had a new or multiple partners over a period of less than a year.  As a matter of personal protection, we recommend annual testing for anyone who has had  a new or two or more sex partners in the past year (we consider this to be health maintenance- we also recommend you get your blood pressure and cholesterol checked regularly).

As a generality, oral sex is less likey to result in transmission of infection than genital or rectal sex.  Risk goes up with multiple exposures and on average, most infections are not transmitted following a single exposure.   there are no data on how the volume of secretions exchanged impacts the likelyhoo of STD transmission.  EWH

[detroit_traveler]

Thanks a lot for your insight, Dr. Hook.

If sexual contact with the same person is planned, can you give some advice to stay safe (besides abandoning a condom, what are unsafe practices?) and do you recommend an STD checkup after, say, ten repetitions?

I'm trying to get a feel for the enjoyment-for-risk tradeoff for the different sexual activities. Infected vaginal fluid in mouth, infected saliva in mouth or on urethra etc. I am completely in the dark to the average volume of bodily fluids it takes for an infection to take place.

[Edward W Hook, MD]

Regarding your sense that the odds of developing cancer if you acquired HPV are 17% - this estimate is far, far too high. The risk is less than 1% although how much less is difficult to say.  Remember most sexually active people (conservatively over 80%) acquire HPV over the course of their lives, and HPV is amongst the most common types of HPV they acquire. The large majority of these infections resolve on their own.  further, the prevalence of oral HPV is far lower than genital HPV and most infectious iseases, including HPV are not transmitted following a single exposure.  This is just not something you should be worried about, particularly if, as you say, this is the only sexual exposure you have ever had.

As far as other STDs, if you use a condom there is virtually no risk.  If not (how could you not know if you use a condom?) the only STDs of major concern are NGU or gonorrhea an these both typically become symptomatic.  If it has been more than a week since your exposure and you have not developed symptoms, I would not worry.  EWH

[detroit_traveler]

I am sorry about the silly question of where HPV-16 lives. After all: If modern medicine can't screen for it, how can it be known where it lives?

And also my statement "Four days after the act, the male detects red spots on his upper thigh/groin (indicative of an infection from a non-carcinogenic HPV strain)." is obviously wrong (as you said it takes ~6 mts for the symptoms to appear).

I'd still appreciate it if you could tell me if I should test for the other STDs and I'm still curious about how likely HPV-16-transmission with an HPV16-positive person is (with the acts described above). 20 to 1 odds (or better) are fine, but a coin toss worries me to say the least.

[detroit_traveler]

Hello Dr. Hook,

There were no other sexual partners, but I am afraid this particular one alone might have been equivalent to a high number of sexual acts with a lot of average people, as this person has had hundreds (perhaps even over 1000) of sexual partners.

I am not concerned about symptomatic HPV, but rather the invisible, high-risk, carcinogenic strains. If one of those is present, I'm afraid  of the 17% odds (Question 4) of the virus evading the immune system. That's why I am looking for a transmission probability: In order to get a feel for the overall likelihood of developing HPV+ oropharyngeal cancer.

With respect to the screening question, I wasn't referring to HPV, but rather other potential STI's. Is it recommended to check for other STI's?

How to people contract the Type-16-HPV? Does it live in the genital area, the mouth area, or can it be anywhere on the body?

Thanks!

[Edward W Hook, MD]

Welcome to the Forum.  Let's not play games.  I will try to help but trying to work through your hypothetical, "what if" questions will do you little good.  The important facts are the, if you have had other sexual partners, you are likely to already have HPV and, amongst the HPV's you could have, HPV 16 is amongst the types that are most common.  Another important fact is that the vast majority of HPV infections will clear on their own without therapy or any sort of consequence.  Finally, when persons acquire HPV, it takes about 6 months, on average, for HPV infections to become apparent.  

My advice to you is that the oral exposure you report was low risk.  If a condom was used the exposure was even lower risk than if a condom was not used.  

Finally, there are no recommended HPV tests for men.  Thus seeking testing is not advised.  

I hope this helps.  If you have a SPECIFIC follow-up question I will be please to try to answer it.  EWH