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Is Oral Sex Infectious?

Terri Rutter, Medical Writer

Oral Sex once considered taboo, is now, according to sexologists and doctors alike, a widely practiced behavior among heterosexual and gay couples. It can add variety to a couple's sex life and be an integral part of foreplay. In fact, because it carries no risk of pregnancy, for some couples, oral sex may even replace intercourse.

"Some people think oral sex is the best thing going," writes Sari Locker in her book The Complete Idiot's Guide to Amazing Sex (Macmillan, 1999).

Yet cunnilingus (oral sex on a woman) and fellatio (oral sex on a man) are not without health risks. In her book, Locker gently warns against inflicting two of them: Do not, she says, bite the penis; and do not blow air directly into the vagina, because this can cause an embolism, which creates a blockage in the blood vessels.

Beyond these precautions, performing oral sex on or receiving oral sex from a partner infected with a sexually transmitted disease, STD, does carry the risk of contracting that infection.

"A number of people who come in don't look at oral sex as being that risky," says Chris Shaw, RN, the nursing team leader at the Infectious Disease/STD Clinic at Massachusetts General Hospital. "People are definitely surprised" to learn they have been infected through oral sex, he continues.

In a two-part review of cases of STD transmission through oral sex found in the medical literature, Sarah Edwards and Chris Carne from the Department of Genitourinary Medicine at Addenbrooke Hospital in Cambridge, England, conclude that oral sex is "implicated as a route of transmission" for gonorrhea, syphilis, herpes, and other infections, as well as HIV. (See sidebar.) Edwards and Carne's review was published last year in the journal Sexually Transmitted Infections.

Gonorrhea

Significantly associated with fellatio, gonorrhea infection in the throat is one of the most commonly seen problems associated with oral sex, says Shaw. Except in a few rare cases, he says, this infection will clear without spreading to other areas of the body. In their review, Edwards and Carne report that homosexual men and heterosexual women are most at risk for this type of infection.

In one case series of patients with gonorrhea, 3.2% of heterosexual men had gonorrhea infection of the throat, while roughly 25% of gay men had a throat infection, and 10% of straight women had a throat infection.

The problem with gonorrhea, says Dr. Jeanne Marrazzo, a researcher and clinician in the Division of Infectious Diseases at the University of Washington, is that some people do not know they are infected. Men frequently experience a burning sensation while urinating, which may not be severe enough to lead to a doctor's visit: Women almost never know they are infected

A gonorrhea infection in the throat may cause the throat to feel sore, says Marrazzo, but not always. In addition, infectious bacteria can lurk in the throat for a long time, she explains, which means that the infection could also then be spread from the throat to a penis.

Herpes

Another infection that can be spread via oral sex is herpes. The herpes simplex virus, HSV, comes in two forms: HSV type 1 and HSV type 2. HSV1 most often infects the mouth area, causing cold sores inside the mouth and on the lips. HSV2 usually infects the genital area. HSV1 can be spread to the genitals during oral sex, explains Marrazzo, if the person giving fellatio or cunnilingus has open sores on his or her mouth. (Some research has shown that there is a small risk of transmitting HSV1 during oral sex even when there are no sores present in the mouth.) This is especially true, she says, if the person receiving is not already infected with HSV1.

This route of infection probably causes more cases in younger people than in older, says Marrazzo, because by the time a person reaches age 30-40, he or she has already been infected with the cold-sore variety of herpes, HSV1. "Estimates vary," she says, "but 15 to 20% of new genital herpes cases are caused by type 1."

Also, she says, when the genitals are infected with HSV1, symptoms are less likely to recur than when the genitals are infected with HSV2, and the lesions tend to be less severe.

Syphilis

Wrongly believed to have been all but eradicated, new cases of syphilis continue to pop up in infectious disease clinics around the country, say Marrazzo and Shaw. Most recently, outbreaks among gay men have been seen in Seattle and in Boston.

Syphilis infection can also be spread through oral sex and even, sadly enough, through kissing.

Chancres, open sores or lesions, are a common symptom of syphilis. They usually show up 3-6 weeks after infection and can occur in the genitals and in the mouth. In either location, these sores can spread infection through contact with other skin, be it mouth or genitals. The sores usually go away after a period of time, but if untreated, the infection stays active in the body for years, causing considerable damage: Oral sex during this time can spread the disease from genitals to mouth or from mouth to genitals.

Wait, There's More

While these three, along with HIV, are the most common infections spread via oral sex, Edwards and Carne turned up anecdotal evidence of other pathogens, including human papillomavirus, chlamydia, and hepatitis spread via oral sex, although at lower rates than those mentioned above.

In this country, one problem in trying to learn precise rates of STD transmission through oral sex is the high rate of underreporting, explains Kathryn Bina from the Centers for Disease Control and Prevention (CDC). This is true for all forms of STD transmission. Because symptoms for many STDs are not usually very severe, a good number of infections are undiagnosed and thus unreported.

In addition, explains Bina, state health departments, the agencies responsible for keeping records of cases of STDs, do not currently record the site of infection on the body. In other words, a gonorrhea infection in the throat would only be recorded and counted as a case of gonorrhea. The CDC is working now with the states, says Bina, to more accurately record the site of infection, so future counts may reveal more accurate rates of STD transmission via oral sex.

Protect Yourself

It's beginning to sound like a mantra, but the experts stand by it: Barrier methods -- condoms for men and dental dams or plastic wrap for women -- between mouths and genitals are the shields that protect most effectively against infection. In her book, Locker, who also recommends against engaging in oral sex without such protections, suggests making them more interesting by using water-based jams or jellies. (Oil can damage or weaken the latex.)

Shaw advises against vigorous tooth brushing or flossing before "going out for the evening when you think you're going to score." These can open up sores in the mouth, which make it more vulnerable to infection, especially to HIV infection. Periodontal disease, especially in severe forms, may be a risk factor for HIV transmission via oral sex. (See sidebar.)

Shaw says he also advises his patients to be careful regarding alcohol and drug use, as with all types of sexual behavior, these can lower inhibitions and increase risk.

 

No Longer Safe

Oral sex has been thought to be one of the least risky behaviors for the transmission of HIV, the virus that causes AIDS, but new research challenges that notion. A study just released by the Centers for Disease Control and Prevention (CDC) found that a small percentage of gay men were infected with HIV through oral sex alone.

"For some, oral sex is equated with safe sex. However, for the individuals in this study and countless others, this false assumption has led to tragic lifelong consequences," said Dr. Helene Gayle, director of CDC's National Center for HIV, STD, and TB Prevention, in a statement released by the agency.

The CDC, in conjunction with the University of California, San Francisco Options Project, evaluated the risk behaviors of 102 gay and bisexual men who were recently infected with HIV. (The study coordinators used a new technology developed by the CDC called Serologic Testing Algorithm for Recent HIV Seroconversions [STARHS], which the federal agency claims can more precisely identify recent infections among serum samples.) Eight of the men in the study (7.8%) were infected via oral sex; most of the men, when interviewed by the researchers, said they believed oral sex to be safer than other sexual practices. The results were presented at the Seventh Conference on Retroviruses and Opportunistic Infections, January 20-February 2, 2000, in San Francisco.

"Other risks are so powerful that they have washed out any effect that oral transmission may have," says Dr. Richard Rothenberg, a professor in the Department of Family and Preventive Medicine at Emory University School of Medicine. (Although not involved in this study, Rothenberg has been researching this subject.) "But oral transmission does play some role." He fears that as more gay and bisexual men choose oral sex over behaviors known to carry a high degree of risk, most notably anal sex, the rates of HIV infection by this route of transmission will also begin to increase.

Natural enzymes in saliva and digestive acids in the stomach are normally protective, which is why oral sex has been thought to pose little risk for passing HIV infection, including the act of swallowing semen, says Rothenberg. "But we still tell people not to do that," he says. Other factors, primarily chronic periodontal disease, which can open passageways into the bloodstream through the mouth, may help facilitate infection via oral sex.

"We want to look at this in more detail," says Rothenberg. But until more information becomes available, he says, "people need to be encouraged not to exchange body fluids" and to use a condom for oral sex.

 

Copyright 2000  The G Network