Expert: Terry B - 9/16/2007

Question
QUESTION: I would consider myself more knowledgeable than most regarding HIV/STDs, transmission, etc., but there are a few issues that seem to cause great confusion. I am a (anal receptive) gay man and merely wish to clarify a few issues in my safe-sex stance.

I have heard from friends on first-hand accounts, as well as reading material, that people have had HIV+ infected semen deposited into their anus, yet, they do not seroconvert. How is this possible? I know researchers say HIV is quite hard to contract, but typically, that refers to occupational exposures.

“Amount of infected fluid” is a key part in transmission. Is it safe to say that most, if not all, of receptive anal sex instances where HIV seroconversions are a result occur from SEMEN, not PRECUM, causing it.

Has anyone ever seroconverted from receiving a penis with NO ejaculation?

Thanks.  


ANSWER: Dear Domonic:

Peace.  Receptive in a sexual act places you at greater risk because you are exposed to more fluid over a greater area and for a longer duration.  As you are probably aware, the concentration of virus in the semen is also a factor, with persons in primary (early) infection and late stage disease having highest concentrations.  

The "mystery" of someone receptive in anal sex not contracting HIV from an infected person has many theories and possibilities, including one study which indicated some individuals missing the receptor sites where HIV attaches to cells.  Compare this also to the approximate 22% transmission rate from untreated infected mother to untreated child; again, why no transmission in 78% of these cases?

Lastly, regarding your specific questions on amount - precum IS semen, as you probably also know - and contains sufficient HIV to infect.  "More" is higher risk, but "some" is risk also.  

I do not have data on precum versus ejaculation - but again you cite the factors mediating degree of risk - amount in this case.  I do not know of reliable retrospective studies which look at HIV transmission in the "precum only" or "insertive not ejaculative" categories, and such a study would of course be unethical to conduct in a lab.

I realize I am confirming some of what you already know, and unable to cite studies for the reasons above, but still hope this helps a bit.

Sincerely,

Terry

---------- FOLLOW-UP ----------

QUESTION: Terry,

If my exposure was receptive anal sex with a condom which did not break and oral sex with no condom (no ejaculation), is testing warranted for me?

Thanks.

Answer
Dear Domonic:

Peace.  I recommend testing after any potential exposure to blood, semen, vaginal secretions, or breastmilk.  It is, in my humble opinion, an important step in responsible sexual activity, to know your status and maintain your health and that of your partners.  

The best of health to you and yours.

Terry