Dear Dr. Kull: My husband and I have an open marriage. I am 43. I have been having a sexual relationship with a man since I was 28. He is married also, although his wife does not know. My question, If this man is dishonest with me re: the number of other females he may have had sex with and lets say one of them has AIDS, is it possible for one of them to give the virus to him and for him to pass it on to me? The AMA states that AIDS cannot be transmitted from a woman to a man but I do not agree with that. Anything is a possibility? I do not have any symptoms that I am aware of, but I do have some anxiety about it. Thank you for your time.

It is not true that HIV cannot be transmitted from a female to a male. Patterns of transmission appear to be different in different areas of the world, but it is clear that men become infected through heterosexual contact. For example, certain regions see extremely high heterosexual transmission rates, like sub-Saharan Africa where 90% of AIDS cases are heterosexually transmitted, 40% being men. Heterosexual transmission is responsible for approximately 70% of AIDS cases in Central/Latin America. These figures are in sharp contrast to the 11% of heterosexually transmitted AIDS cases in the U.S, where female to male transmission is quite low.

More research should reveal the factors that account for the variances in transmission rates. Certain biological determinants may play a role (circumcision, STD rates, immune response), while more qualitative determinants, like sociocultural issues, may play a role as well.

It is impossible to predict whether or not your partner is putting you at risk for infection. Certain factors increase the odds for him being infected (sex with men, sharing injection needles), but otherwise the odds for transmission are low. However, since transmission is always a factor when you have sex with a partner of unknown HIV status, condom use is recommended.

RMK