Transmission Route

[curiousdude]

Dear Doctor,

Thank you for providing this great service. As you kow for yourself, there is a lot of information out there regarding how risky certain types of sex scenarios are and many readers are confused. I have a few questions myself:

I recently paid a women to have sex with her. We had protected vaginal and anal sex. When I ejaculated I pulled out and while pulling out the condom got kind of stuck in her. It was "hanging" half way out I do not believe my penis touched anything. Anyway I went straight to the bathroom to wash myself off. I believe my risk here is minor if there was any risk at all. Correct?
Another question I am asking myself, how does the insertive partner gets infected while having anal sex with a women? What type of bodily fluids are found in womans anus/intestence  that transmit the disease?

Another question I have is regarding the hand to genital contact. If no case ever has been reported for this type of HiV transmission route, was it because higher risk scenarios took place at the same time? If HIV needs to find a entry point into the body, why would fingering with a cut not be risky?
I am asking because when I had again protected sex with a woman of unknown status I took my condom off afterwards with a finger that had a few hours old papercut on it. After contract It started to sting and again I went to bathroom to wash my hands/fingers thouroughly. Should I have any worries here?

Last but not least: Can you answer briefly why testing after a low risk encounter is conclusive after a shorter period of time compared to a higher risk encounter. If you got infected, you got infected. Right?
Again, thank you very much. I hope many more readers will benefit from those questions as well.
Best Regards,

Curious Dude

[H. Hunter Handsfield, M.D.]

You are right; the risk you describe was minor to zero.  Most HIV infections from insertive sex--anal or vaginal--occur via the urethra, the penile opening.  If a man is uncircumcised, some infections probably occur because of minor trauma to the foreskin and head of hte penis.  Anal sex is risky because it is traumatic to the rectum and often there is blood, even if not enough to notice.

People tend to think it takes "just one virus" to catch HIV.  Not true. If you aren't exposed to thousands (maybe millions) of virus particles, infection doesn't take. Probably people don't carry enough secretions/virus on their hands to transmit.  You have no worries.

I have explained this repeatedly.  Please read the forum.  The tests perform no differently after high versus low risk exposures.  But if you start with an exposure that has only 1 in 10,000 risk of HIV, then a test that picks up 90% of infections (say at 4 weeks) changes that risk to 1 in 100,000.  Most of the time, that's good enough.  But if you have had an exposure with a 1 in 100 risk (say anal sex with a known HIV infected person), then the same test result still leaves a 1 in 1000 risk that the person caught HIV.  In that circumstance, it is desirable to have a test that will pick up 99% of infections--i.e., testing at 8-12 weeks.  My advice about testint interval always takes into account not just test performance, but the overall risk sitatuion.   The lower the risk, the more reassuring a negative test result.

HHH, MD

[curiousdude]

Thank you for your quick response. Would you recommend testing in my situation? Would you assume it is safe to have unprotected sex with my partner without harming her?
These are the last questions I will ask regarding this.
Again, thank you very much.

[H. Hunter Handsfield, M.D.]

I never recommend testing after any particular exposure of concern, unless it is much higher risk--like vaginal or anal sex with a high risk partner (e.g., a gay/bi man) or a known-infected partner.  Sexaully active people should have periodic HIV tests, like every 1-2 years, rather than worrying about particular events, especially zero risk situations like you suggest.  So if you haven't been tested recently, you might do it now, since it's on your mind.  But not because of the specific exposures you imply.