Chances of acquiring a communicable STD

[rayan]

I have searched the archives and the internet and cannot find a simple way of comprehending the risk of catching an STD that can be retransmitted to someone else. Is it possible to provide a "best experience and judgement" description of the highest risk of infection and respective STD, using statistical descriptions  of 1/100, 1/1000, 1/10000, 1/1000000 for the following activities:  



Assume a male/female encounter using condom only for intercourse and neither partner has any visible signs of lesions or warts.



1) Male receiving oral sex



2) Male giving oral sex



3) Intercourse



4) Genital to Genital touching



5) Female receiving oral sex



6) Female giving oral sex



This would be very great service for a vast number of internet users seeking knowledge on this subject.



Thanks and keep up the great work.

[H. Hunter Handsfield, M.D.]

Less precision is available than you seek.  It is essential to undertand that such statistics are only a very rough guide.  For many of the exposures you describe it is little more than guesswork; actual data simply do not exist.  In addition, no such risk estimates take into account numerous factors that markedly modify the odds for any particular exposure, such as duration and stage of HIV, viral load, and antiviral therapy in the infected partner; presence of other STDs, especially herpes; certain sexual practices (e.g., "dry sex", a common practice in some subsaharan Africa contries); circumcision status; and others.



The numbers I provide are off the top of my head.  They assume no condom or other barrier.  Other forum readers might provide other information or links to official estimates from CDC or other sources.



1) Male receiving oral sex by an HIV infected partner:  Unmeasurably low; few such transmissions have been documented, and some of those may be questionable.  As a guess, maybe 1 in 100,000?



2) Male performing fellatio on an infected partner:  Very low, probably no more than 1 in 10,000; perhaps higher with intraoral ejaculation than without, but no data available.



3) Vaginal intercourse:  Around 1 in 1000 to 1 in 2000; higher M->F than F->M.



4-6) Genital apposition without penetration and cunnilingus (both directions):  Probably zero or close to it.  To my knowledge, there are no reports in which such transmission was reported or claimed.



Others you don't mention, but which come up commonly in questions on this forum:



Anal sex:  Around 1/100 (top to bottom) to 1 in 200-500 (bottom to top).



Oral-anal (rimming):  No data available, probably under 1 in 10,000 in either direction, but that's merely a wild guess.



Hand to genital contact:  Zero (even when there are cuts or abrasions on the hands).



Kissing:  Zero, or close to it.



Shaking hands, non-sexual personal contact, touching HIV-contaminated surfaces, etc:  Zero, even with cuts or abrasions on the hands.



Thanks for the opporunity to put this in a single message.  Undoubtedly I will be referring lots of future questions to this thread.



HHH, MD

[HHH,MD]

I should have clarified that I responded only for HIV, not for STDs in general.  That of course is where most of the concern comes up on this forum and elsewhere.  STD transmission risks generally are much higher than for HIV; vary widely between STDs (and I do not have time to try to respond for each separate STD); and in general even fewer data are available than for HIV, so most numbers would be even more uncertain.



HHH, MD

[rayan]

I have read many of your responses in the archives and am impressed with your extensive background, so your guesses are better than any other source that I have been able to find.  My question was really for those of us who are concerned with getting any communicable STD (HIV and others) and would still like to know what STD is most likely to be contracted and its relative risk from my early question.  For instance you have given responses such as "very low" to actual questions that are similar to the ones describe above but its unclear what that means.



Basically I am looking for what are my chances of geting the most likely STD for the activies as described above. I apolgize for my question not being clear.



Thanks

[H. Hunter Handsfield, M.D.]

Sorry, it just isn't possible.  The only data available are that if a woman has gonorrhea, the transmission risk to a male partner through vaginal sex is around 20% (1 in 5) for each exposure.  Male to female transmission is around 50% (1 in 2).  No numerical estimates are available for anal sex (but probably similar to vaginal) or oral sex (lower than vaginal, especially from mouth to urethra). No data are available for chlamydia or herpes, HPV, or hepatitis B, but maybe about the same as for gonorrhea (that's only a guess).  The major determinant of risk is whether or not someone selects a partner with active infection--and that is all over the map, and I cannot remotely predict your risk, not knowing where and how you select your partners.



HHH, MD

[NEEDS HELP PLZ]

IM NOT JUMPING THREADS BUT I WAS READING AM I A GONNER AND HE ASKED A QUESTION THAT YOU DIDNT ANSWER.HE SAID THAT HE GOT DONE WITH SEX AND TOOK A SHOWER AND ASKED IF THIS LOWERED HIS EXPOSUER LEVEL OR LOWERED HIS CHANCES OF CATCHING ANY THING?YOUR ANSWER TO HIS QUESTION WOULD BE APPRICIATED SINCE I COULDNT PUT THIS ON THAT THREAD BECAUSE COMMENTS WERE CLOSED I HAD TO PUT IT ON ONE THAT WOULD ALLOW ME TO. THANX