I attended a sex talk, and the speaker confused me when she was talking about preventing STDs. I was under the impression that you had to have sex to have an STD, but she said it was possible to have one without having sexual intercourse. My boyfriend and I are still virgins, and want to be until we are married. We do fool around some, and I started worrying that I could be at risk even though we aren't having sex. Is this possible?

A.S.

As you know if you watch presidential politics, the definition of sex depends on who is defining it. Few, if any, sexually transmitted diseases (STDs) require actual sexual intercourse for transmission. For example, studies have found that oral sex can transmit HIV (the virus that causes AIDS), hepatitis B virus, herpes, genital warts, syphilis and gonorrhea. Other acts, such as petting, could possibly transmit some of these infections as well. Contact with infected body fluids (particularly blood, semen and vaginal secretions) is necessary for spreading HIV and hepatitis B. Therefore, touching and petting (without ejaculation) would not be likely to pass these viruses from person to person. However, the same is not true for genital warts or herpes. Only contact with the lesion is needed to spread these infections.

I am not sure what you mean by fooling around, but my definition would include some contact with the genitals. If you have been doing this, then there is some risk, depending on the circumstances. I hope that you understand an important aspect of disease transmission: If your partner is not infected with an STD, then you cannot possibly catch an STD from him, regardless of the sex act that you perform. If you are absolutely sure that your partner is a virgin, then he is unlikely to have any STD. Even if you had sex with him, you could not catch anything. (One exception to this is if a person's partner contracted an STD that is also spread in nonsexual ways. For example, HIV and hepatitis B can be spread from mother to child before or during childbirth, or by needle-sharing among people who use intravenous drugs.)

The idea that a particular sex act itself is risky even with an uninfected partner is a common misconception about HIV as well. For example, in the United States, anal intercourse between homosexual men is rightfully considered very high-risk activity. However, if both partners are free of HIV, then the act of having anal intercourse does not pose any risk of HIV infection.