I received oral sex from an HIV positive partner and I didn’t wear a condom. Could I become infected from that kind of encounter? If so, what is the probability?
I have seen no evidence in the published medical literature suggesting that the type of activity you describe would put a person at risk of testing HIV positive. Also, most AIDS experts believe saliva contains certain enzymes that would destroy HIV if it were present in saliva.
A large study of sexually active sero-diverse couples (one partner HIV positive, the other HIV negative) who failed to use condoms consistently reported no cases of so-called HIV transmission to a negative partner as a result of unprotected intercourse in 10 years of follow up. Although only heterosexual couples participated, it would seem highly unlikely that male-to-male oral sex from a positive partner could do what regular intercourse couldn’t.
The same study also postulates that it would require 1,000 acts of unprotected “heterosexual” intercourse with an HIV positive male partner for their HIV negative partner to become positive. In other words, you would need to have sexual intercourse once a day for almost three years with someone who tests positive in order to possibly test positive yourself. I used the word "postulate" in reference to the study because there was no data to support even those long shot odds (no pun intended).
If you want to know more about the study, it is Padian NS, Shiboski SC, Glass SO et al. (1997). Heterosexual transmission of HIV in Northern California: Results from a ten-year study. American Journal of Epidemiology 146(4); 350-357.
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