Risk of transmitting HIV through oral sex is much lower than with anal or vaginal sex.
...according to a fact sheet recently issued by the Centers for Disease Control and Prevention (CDC). The sheet emphasizes that while the risk of transmitting human immunodeficiency virus (HIV) through oral sex is much lower than that associated with anal or vaginal sex, oral sex can still result in the transmission of HIV and other sexually transmitted diseases (STDs), including herpes, syphilis, gonorrhea, genital warts (HPV), intestinal parasites (amebiasis), and hepatitis A.
The sheet explains that many teens believe oral sex-defined as giving or receiving oral stimulation to the penis, vagina, and/or anus-is safe. The CDC cites a national survey conducted by the Kaiser Family Foundation that found that one in four sexually active 15- to 17-year-olds believes you cannot contract HIV by having unprotected oral sex; another 15% are uncertain. Further, many teens do not consider oral sex to be sex at all.
Apart from abstinence, the best way to reduce the risk of transmission during oral sex, according to the fact sheet, is to use a physical barrier, such as a dental dam or a condom, the latter of which can be cut open for vaginal and anal contact, or left in tact for fellatio. While at least one scientific article suggests that plastic food wrap is effective at preventing the transmission of herpes simplex virus during oral-vaginal or oral-anal sex, the jury is still out on whether it is effective at preventing the transmission of HIV or any other STDs, and it is not manufactured or approved by the Food and Drug Administration for this purpose.