I've gone through a lot of different entries both in the STD Community, and in Dr. HHH & Dr. Hook's expert forum. My question/issue is not at all an uncommon one, a mistake many of us have made it seems: performing cunnilingus on an escort/stripper/CSW in the United States (Las Vegas in my own case) without protection (dental dam).
Below I will list what I believe I have learned. If those on the forum who are particularly knowledgeable (auntiejessi, monkeyflower et al) can confirm I've got this right, it would certainly be appreciated by me -- and I think would be a useful search result for people like me, who've been looking for "one-stop-shopping" questions answered about this issue, without getting sidetracked on all the very detailed bits people usually put in their questions that are typically relevant only to them (i.e. "I performed unprotected cunnilingus AND got a ********" or "I had a cold sore at the time and I gargled after and then watched the Lakers-Celtics game for 2 hours, does this put me at a higher risk?" etc etc).
What I think I know:
1) The risk of HIV infection is DEFINITELY almost non-existent, and may in fact actually be zero risk.
2) The risk of contracting an STD is higher -- but generally speaking, very low as well. It is somewhere between very, very unlikely and close to flat-out impossible. In particular, it is worth noting that Dr. HHH states that in his 30+ years of working in the field, he's never seen one confirmed/highly plausible case of contracting an STD by performing cunnilingus.
2a) The risk *can* be higher, if you have extenuating circumstances (i.e. open cuts in the mouth, etc). However, worst-case, this is perhaps a doubling or tripling of odds that were very low to begin with.
3) The most likely/plausible STDs that could be contracted are oro-facial herpes and oral gonorrhea. However, both of these incidences are rare. Syphillis is also possible, but highly unlikely due to the low % of the population carrying syphilis to begin with (including CSWs).
4) Bottom-line: STOP PANICKING! Cunnilingus is not exactly "safe sex," and you're an idiot if you do this repeatedly (or in my case, ever again). However, there is ZERO chance you've contracted HIV from a one-off encounter like this, and an ALMOST ZERO chance you've contracted any other STD. And even if you're somehow the unlucky lottery-winner-in-reverse and you caught something, the odds of you passing this on to any other partners are very, very low.
5) So why is there all sorts of information/sites out there saying otherwise? Partly due to moral/political motivations or pressure, partly due to ignorance/outmoded thinking about STD spread, and probably mostly due to covering-your-*** vis a vis legal concerns. STDs theoretically CAN be spread by cunnilingus, yes, so for doctors (and lawyers for that matter), that fact trumps the fact that in practice it is VERY RARE. An overabundance of caution.
As I said, if the community experts can weigh in simply to confirm my summary is correct, I would really appreciate it, and I'd bet others out there searching MedHelp would too.