I have a couple of HPV-related questions:

1) I had a common wart on my ring finger that I ripped off, and it bled. Problem was, I had somewhere to be shortly after, so I took a shower while it was still bleeding, and some of the blood was washed down my body (I tried to wash it all off). Would it be possible to auto-inoculate my genitals in this scenario? Also, what are the chances that ripping off a common wart would expose me to HPV-16? I feel like this is a pretty unlikely (almost impossible) scenario given that HPV16 doesn’t cause cutaneous warts, but I’d like to hear your thoughts. 

2) Amongst all HPV strains, how common is HPV16? From what I’ve read, it’s one of the most common strains overall—not just one of the most common high-risk strains. I saw on the oral cancer foundation website that only 2,600 oral HPV-16 infections are present in the US at any given time, and that just seems crazily low to me given how common the strain is, and given that there are ~12,000 cases of oral cancer every year in the US. Since it’s typically asymptomatic, I feel like it’s hard to get a good grasp on how common it actually is. 

3) Would one instance of oral exposure (i.e., oral sex) to an individual with an HPV-16 lesion on their penis automatically lead to oral infection of HPV-16? My understanding is that oral infection is significantly lower risk than genital infection because HPV doesn’t take quite as well to the oral cavity, so it usually takes repeat exposures. 

4) finally, if you had to estimate, what percent of oral HPV-16 infections clear on their own? Is it still that 90-ish percent figure that is so often quoted for other strains? 

Thanks again for your time. 

There are around 120 different HPV types, of which about 40 primarily affect the genital area and are sexually transmitted. The others rarely cause genital infection, and that's especially true for HPV type 1, the usual cause of common hand and foot warts. The likelihood your had wart was HPV 16 or any other genital strain, either high- or low-risk for cancer, probably is zero or close to it.

1) For those reasons, it is exceedingly unlikely that your finger wart is caused by an HPV type that would infect the genital area. And even if it was a rare case of hand wart due to a genital type, HPV auto inoculation is rare; the immune system typically prevents new infections to take hold with the HPV type with which one already is infected. In addition, the shower water would delute any virus too much to have any risk. Finally, soap instantly kills HIV and would prevent auto-inoculation.

2) Your own research has been accurate:  HPV 16 is among the most common of all HPV types, at least among the genital types. However, there is no discrepancy between its high frequency and the relatively low number of throat cancers caused by HPV 16. Even among the highest risk types (HPV 16, 18, and several others) the vast majority of infections do not lead to cancer of the cervix, vulva, penis or pharynx (throat). My understanding is that it's closer to 16,000 cases of oral [pharyngeal] cancers attributed to HPV per year, by the way; check out the national data from the American Cancer Association, www.cancer.org. But of course 16,000 is a teeny number in a nation of 333 million -- far lower than other important cancers like colon, prostate, breast, etc. (Around 40% of all deaths in the US result from cancer. Among those, the ones caused by HPV are a very small minority. It's OK and entirely normal to be worried about cancer and take reasonable steps to lower the risk, when the risks are known. But even among the most sexually active persons or those with the highest risks and rates of HPV (whether anogenital or oral), other cancers are far more common than those due to HPV.

3) One instance of oral sex probably carries under one chance in millions or billions in leading to oral cancer. And yes, the genital HPV types are generally believed to take hold less well in the oral cavity than the genital or anal area.

4) What proportion "clear" depends on the definition of the word. By some standards, 90% (or more) is a pretty good number. Well over 90%, perhaps 99%, are controlled by the immune system to a point they cannot be detected and can be considered cleared. However, undetectable HPV DNA can persist, and some experts believe it always does so -- that is, that few if any HPV infections are totally cleared, and that many or most could reactivate and be detected, transmitted sexually, and perhaps cause cancer or warts. For example, beyond age 30 or so, the majority of cervical HPV infections detected by Pap smear, and the majority of genital warts, and certainly some cancers result from reactivation of longstanding infection -- not newly acquired HPV. 

I hope these comments are helpful. Let me know if anything isn't clear.

HHH, MD

1) so you’re basically saying, if I have HPV16, the odds drastically point to me acquiring it from a past partner? The partner in question had 15+ sexual partners before me, while she was my first sexual partner (the first of only two). I ask this because I recently discovered a white lesion in my urethra that is basically symptomless other than maybe slightly more frequent urination, but I have no clue how long it has been there (I’d imagine years at this point—I thought I had what was a UTI years ago, but that might have caused this), and based on what I’ve read, it sounds/looks like a flat wart from HPV16. Ive done a urinalysis for mycoplasma/chlamydia/herpes, everything else other than HPV and all tests are negative. I’ve been looked at by dermatologists and urologists and they don’t seem concerned, but this new discovery worries me.  

2) understood. Yeah my concern wasn’t the number of oral cancer cases per year as much as the actual number of people with oral HPV16 infections at any given time in the US—the oral cancer foundation lists the figure as 2,600, which I feel is low. 

3) would this still be the case if my newly identified lesion is indeed due to HPV16? We had one instance of oral sex (I didn’t finish), and I’m terrified that I basically damned my ex partner to throat cancer in the future.

4) Okay, thanks for the clarification. Given that, would you still estimate that 90%+ of oral HPV16 cases would be suppressed in otherwise healthy, young people? I’m petrified for her health—I only learned about HPV16 a few weeks ago and it seems like the stuff of nightmares. 

2) OK.

3) It's not HPV 16. Nobody in the world ever "damned a sex partner" to throat cancer!

4) I stand by the statement above. There are plenty of potential nightmares in our life. HPV 16 isn't one of them.

If you remain so obsessed, get vaccinated against HPV -- which is recommended for all sexually active people. Given your minimal sexual experiences so far, the chance is that you are still susceptible to most of the 9 HPV types prevented by the vaccine, including HPV 16. Vaccination also modestly lowers the frequency of reactivation in people already infected. 

2) I read a case study of a male with a urethral flat wart caused by HPV16, and it sounds similar to what I have. If that is what I have, I’d assume it’s more likely that I got it from a prior, more sexually active partner compared to from a common wart?

2) It's a mistake for worried persons to search for the one in a million (or billion?) long shot of a single event and allow it to worry them. Nonsense.

3) I didn't comment on the 2,600 figure above because I don't understand it and don't know its reliability. I would have thought a lot more people have oral HPV 16 at any point in time. The much more important number is ~16,000 cases throat cancer per year, a teeny proportion of all persons who ever acquire oral HPV 16.

4) A single oral encounter with the infected body part of a person with HPV 16 has nowhere near 100% chance of being transmitted. Probably somewhere around one percent to 10 percent, I would guess.

I suggest you put life's risks in context. According to the National Safety Council, the average person residing in the US has about one chance in 1,756 of dying of an accident in the next 12 months. My advice therefore is to use your seat belt, keep firearms out of the house (or manage them sensibly), and keep the batteries fresh in your smoke alarms. And not worry about cancer from HPV!

That concludes this thread. I hope the discussion has been helpful.