Oral sex with a condom or dental dam: It’s one of those things things that sexual health educators preach but which people rarely practice. A reminder of that came earlier this week with the release of a CDC report noting that “adolescents perceive fewer health-related risks for oral sex compared with vaginal intercourse” and, as a result, young people may “be placing themselves at risk of STIs or HIV before they are ever at risk of pregnancy.”
My immediate reaction to that was: Well, but there are fewer health-related risks, right? Then I came across this remark in HealthDay from Christopher Hurt, a professor in the Division of Infectious Diseases at the University of North Carolina at Chapel Hill: “I would say that the risk of STD transmission through oral sex is underappreciated and underestimated. As part of sex education programs, kids need to be made aware of that fact that oral sex is not a completely risk-free activity.” But, I wondered, just how dangerous is it?
It turns out that putting a solid figure on the danger is difficult. Nikki Mayes of the CDC’s media office says, “As far as I’m aware, no studies have quantified the exact risk for all STIs [through oral sex],” and the CDC doesn’t gather data on STIs contracted through oral sex. It’s difficult to attribute infections to any single sex act — most people who contract STIs engage in a variety of potentially risky sexual practices.
But we can look at what we know about the transmission risks of particular STIs, starting first with the one that scares people the most: HIV. The greatest danger when it comes to oral sex is believed to be with fellatio for the “receptive partner.” (Now here’s a mind fuck: In clinical lingo, “receptive oral sex” refers to performing oral sex on someone — or “giving head,” as the kids say — not to “receiving it.” You can think of it this way: The receptive partner is receiving the penis or vagina in their mouth.) The website of AVERT, an international HIV and AIDS charity, explains that transmission can occur when “sexual fluid (semen or vaginal fluid) or blood (from menstruation or a wound somewhere in the genital or anal region) [gets] into a cut, sore, ulcer or area of inflammation somewhere in their mouth or throat.”
A University of California, San Francisco, study put the per-contact risk of transmission through “receptive” fellatio with an HIV positive partner at 0.04 percent. (For perspective, consider that the same study found a much higher per-contact risk of 0.82 percent for unprotected receptive anal sex.) The researchers calculated the rate of HIV transmission to be 4 out of 10,000 acts of fellatio. Without ejaculation in the mouth, though, some experts have called HIV transmission via performing fellatio “extremely low risk.”
As for the danger of having someone perform unprotected oral sex on you: “The only risk in this scenario would be from bleeding wounds or gums in the HIV positive person’s mouth or on their lips, which may transfer blood onto the mucous membranes of the other person’s genitals or anus, or into any cuts or sores they may have,” according to AVERT.
(I hope that all makes sense — my brain still hurts from trying to understand the concept of “receptive oral sex.”)
Now that we’ve addressed people’s worst fear, let’s turn to the most realistic worry: herpes. It presents the biggest threat of transmission through oral sex, and barrier methods don’t always prevent it. Most risky is the transmission of HSV-1, which typically shows up as sores around the mouth but which can be transmitted from the mouth to the genitals. One study found that women who received oral sex but didn’t have vaginal intercourse were more than nine times as likely to contract the virus than sexually inactive women. (That’s compared to women who only had vaginal intercourse, which were at a lesser risk.) HSV-2 can also be transmitted from genitals to mouth, although it’s rarer.
The other leading risk through oral sex is gonorrhea, says Hurt. STD clinics have reported that 5 to 10 percent of patients have gonorrhea of the throat. Scarier still: Cases of antibiotic-resistant oral gonorrhea are on the rise (meaning these cases are harder to treat but not incurable).
Chlamydia and syphilis are in the second tier of risk through oral sex. A Chicago study found that 13.7 percent of syphilis cases were attributed to oral sex. Generally, though, it’s believed to be uncommon. As for syphilis, that seemingly antiquated infection, it’s “easily transmitted” during oral sex — “if a person’s mouth comes into contact with an open sore or a skin rash caused by the infection,” according to AVERT.
As for HPV, Hurt says, “We really don’t know what the risk is … but it clearly can infect in and around the mouth, as well as in the genital tract.” One study described the risk as “small.” You’ve probably seen the scary headlines about oral sex causing cancer, but as I reported in the past, oral cancers linked to HPV are very rare: Approximately five per 100,000 people. (And most oral cancers are tied to HPV 16, and we have a vaccine for that now).
Further down the list of risk are Hepatitis A, gastrointestinal infections, and parasites, among others — fun times, y’all!
One takeaway is that — sorry, fellatio fans — blow jobs tends to be riskier than cunnilingus. “Across all STIs and all sex acts, generally the receptive partner is the one at greater risk for STI and HIV acquisition, the idea being that wherever ejaculate winds up, that’s also where the greatest burden of infectious material will also wind up,” says Hurt. But that hardly means that cunnilinguists are in the clear: He also says that the risk of contracting syphilis, herpes or HPV by performing oral sex on a woman is “arguably just as high” as with fellatio “since these infections can occur both inside the vagina and on the skin surface.”
There’s a yawning gap between sexual health experts’ recommendations and people’s actual behaviors: A 2004 survey of U.S. adults found that 82 percent of sexually active participants never used a condom or dental dam during oral sex. A U.K. survey of 16 to 18 year olds found that only 2 percent of those who had experienced fellatio consistently used condoms. “It’s pretty uncommon for people to actually use condoms or dental dams when performing oral sex,” says Hurt. Flavored condoms and dental dams help to encourage the practice, but “they can only go so far towards making [oral sex] through latex or polyurethane a pleasurable experience for either partner.”
So, you see, it’s hard to nail down the exact risk of unprotected oral sex, but Hurt says, “The most important point is that it’s all relative, and oral sex isn’t risk-free.”