I'm a 30 y/o female who has been vaccinated with HPV (quadrivalent) and Hep B, tested -ve for HIV and Hep C last year. No sexual activity since my last test. 

I was recently at a party and ended up using a vape pen from my friend who is a homosexual man. He has a history of multiple sexual partners, claims to follow safe sex. I am extremely worried about sharing his vape pen. I am not sure who used it, how clean it was. Am I at risk for contracting HIV, strains of HPV not covered by quadrivalent vaccine or any other STIs? He engages in oral and anal sex and I am not sure where all the vape pen has been. I am very worried. Should I get tested? If so, when?

Thanks.

You needn't be worried at all. None of the infections you mention, or any STI, ever is transmissible by shared vaping equipment, other oral devices, drinking glasses, etc -- for the same reason that kissing also doesn't transmit them. If you think about it, if this sort of exposure could transmit such infections, then the roommates of infected persons -- including those at especially high risk, including some men who have sex with men -- would also be getting non-sexually transmitted infections (through shared kitchen, toilets, silverware, etc). But this also never happens. It takes sex itself.

Since you ask specifically about HPV, I'll just say that oral infections are uncommon and nobody has ever been known to be infected in this manner. Even oral sex is low risk for HPV. And anyway, you can be absolutely sure you have had (or will have) HPV infections due to strains not covered by the vaccine. There are over 100 sexually transmitted HPV types, and assuming you are (or will be) sexually active, that's where you're going to get these HPV infections, not from trivial oral contact of this sort. As for HPV, it is rarely if ever transmitted by any oral contact of any kind. If you were to be kissed or receive oral sex (cunnilingus) by an HIV infected partner, you wouldn't catch it.

For sure you do not need testing for HIV or any other STI on account of this event. Of course you may be at risk if you resume potentially risky sexual activity, in which case testing for common STIs from time to time will make sense (as you apparently have done in the past). But that's all.

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

HHH, MD