Question: What is this study about?

Answer: The purpose of this particular study was to ascertain the extent of HIV transmitted by oral sex among men who have sex with men who were identified with HIV within 12 months of becoming infected.

Question: Hasn’t oral sex already been identified as a method of transmitting HIV?

Answer: Yes. However, this is the most definitive study to date. Earlier studies have been published.

Question: What is the risk of HIV transmission from oral sex?

Answer: The likelihood of transmission of HIV from an infected person to an uninfected person varies significantly depending on the type of exposure or contact involved. The risk of becoming infected with HIV through unprotected (without a condom) oral sex is lower than that of unprotected anal or vaginal sex. However, even a lower risk activity can become an important way people get infected if it is done often enough. The Project found that 7.8% (8 of 102) of recently infected men who have sex with men in San Francisco were probably infected through oral sex. Most of these men believed that the risk was minimal or non-existent.

Question: What are the exact ways that HIV was transmitted in this study?

Answer: Nearly half (3 of 8) of these cases reported oral problems, including occasional bleeding gums. Almost all (7 of 8) of these men reported to have had oral contact with pre-semen or semen.

Question: How do you know if the study participants were telling the truth about their sexual history?

Answer: Oral transmission of HIV is very difficult to single out as the only way that HIV is transmitted because few people engage exclusively in oral sex. A number of specific questions were asked by a trained evaluator. The participants’ risk behaviors were assessed by using clinical interviews, counselor intervention, epidemiologic interview, partner interview when possible, and final disposition of transmission risk. Of the 8 cases, 4 reported protected anal intercourse, without the condom breaking, with persons who were either HIV infected or had an unknown serostatus. Men in this study who reported that they were uncertain if the condom was used properly were eliminated from this study.

Question: Was this a surprise finding?

Answer: Yes and No. The percentage of recently infected men enrolled in this study who were probably infected through oral sex (8%) was higher than many researchers had thought likely or found in other studies. More media attention appeared to be placed on this particular study, probably because of the higher number of study participants. There appears to be evidence that higher risk activities (anal sex) among men who have sex with men is decreasing while lower risk activities (oral sex) among these men is increasing. Oral sex has always been considered a lower risk activity but is certainly not risk free.

For an easily printable PDF on this topic, go to http://www.cdc.gov/hiv/resources/factsheets/PDF/oralsexqa.pdf