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What is oral sex?
Oral sex involves giving or receiving oral stimulation (i.e. sucking or licking) to the genitalia. Fellatio (also known as a 'blow job') is the term used to describe oral sex given to a man, cunnilingus is the term which describes oral sex given to a woman, and anilingus is oral-anal contact.
Is oral sex common practice?
Many studies have shown that oral sex is practised by sexually active men and women of all ages, both gay and straight. It is a very common practice and may be performed on its own, or before or after sexual intercourse.
Is oral sex safe?
A number of studies have demonstrated that oral sex is not necessarily safe sex. Both giving and receiving oral sex can lead to the transmission of sexually transmitted infections or sexually transmitted diseases (also known as STIs or STDs).
Which STDs are transmitted via oral sex?
If a person is infected with any of the following STDs, there is a risk they could transmit the infection via oral sex.
- The most common STD transmitted via oral sex is herpes. There are two main types of herpes simplex virus (HSV): HSV type 1, which usually causes cold sores around the mouth, and HSV type 2, which generally causes sores around the genitals. If a person has HSV type 1 and they give oral sex to another person, the herpes could be transmitted to the genital area of the other person, causing genital sores. This process can also work in reverse, with HSV-2 transmitting from the genitals to the mouth of the other person during oral sex, though this is rare.
- Gonorrhea can easily be transmitted via oral sex. The infection is usually passed from infected genitals to a person's throat, but can also be passed from an infected throat to a person's genitals. The body will almost always naturally clear the throat of the bacteria that cause gonorrhea within three months, although infections in the genital tract will usually require antibiotics to cure.
- Syphilis is 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.
- It is possible (but thought to be not very common) for the human papillomavirus, which causes genital warts, to be transmitted through oral sex.
- Chlamydia can infect the throat via oral sex, although this is thought to be uncommon. People with chlamydia may not have any symptoms and may not be aware they are infected.
- The hepatitis A virus is found in human faeces, and may be passed on during anal-oral sex.
- Hepatitis B is contained in sexual fluids and blood and may be transmitted during oral sex in a similar way to HIV (see below).
- Hepatitis C is generally only contained in blood, and will only be transmitted if there is blood present during oral sex.
- Gastrointestinal infections and parasites may be passed on during oral contact with the anus.
Can HIV be transmitted during oral sex?
HIV can pose a small risk for both the active (person giving the oral stimulation) and receptive (person receiving oral stimulation) partner.
Transmission from an HIV positive receptive partner to an HIV negative active partner may occur when the active partner gets sexual fluid (semen or vaginal fluid) or blood (from menstruation or a wound somewhere in the genital or anal region) into a cut, sore, ulcer or area of inflammation somewhere in their mouth or throat. The linings of the mouth and throat are very resistant to viral infections such as HIV, so infection is unlikely if they are healthy.
Transmission from an HIV positive active partner to an HIV negative receptive partner is generally believed to be less common. This is because HIV is normally only present in saliva in very low levels that are not sufficient to cause infection. 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.
What is the risk of HIV transmission via oral sex?
“The risk of HIV transmission from an infected partner through oral sex is much smaller than the risk of HIV transmission from anal or vaginal sex.”
The risk of HIV transmission from an infected partner through oral sex is much smaller than the risk of HIV transmission from anal or vaginal sex. Because of this, measuring the exact risk of HIV transmission as a result of oral sex is very difficult. In addition, since most sexually active individuals practice oral sex in addition to other forms of sex (such as vaginal and/or anal sex) when transmission occurs, it is difficult to determine whether or not it occurred as a result of oral sex or other more risky sexual activities. Finally, several co-factors can increase the risk of HIV transmission through oral sex, including oral ulcers and wounds, bleeding gums, genital sores, genital or oral piercings, and the presence of other STDs.
When scientists describe the risk of transmitting an infectious disease, like HIV, the term "theoretical risk" is often used. Very simply, "theoretical risk" means that passing an infection from one person to another is possible, even though there may not yet be any actual documented cases. "Theoretical risk" is not the same as likelihood. In other words, stating that HIV infection is "theoretically possible" does not necessarily mean it is likely to happen - only that it might. Documented risk, on the other hand, is used to describe transmission that has actually occurred, been investigated, and documented in the scientific literature.
Various scientific studies have been performed around the world to try and document and study instances of HIV transmission through oral sex. A programme in San Francisco studied 198 people, nearly all gay or bisexual men. The subjects stated that they had only had oral sex for a year, from six months preceding the six-month study to its end. 20 per cent of the study participants (39 people) reported performing oral sex on partners they knew to be HIV positive. 35 of those did not use a condom and 16 reported swallowing semen. No one became infected with HIV during the study, although the small number of participants performing oral sex on a person living with HIV meant the researchers could only say that there was a less than 2.8 per cent chance of infection through oral sex over a year. 1 In 2000, a different San Francisco study of gay men who had recently acquired HIV infection found that 7.8 per cent of these infections were attributed to oral sex. 2 However, the results of the study have since been called into question due to the reliability of the participants' data.
Measuring the exact risk of HIV transmission as a result of oral sex is very difficult.
In June 2002, a study conducted amongst 135 HIV negative Spanish heterosexuals, who were in a sexual relationship with a person who was HIV positive, reported that over 19,000 instances of unprotected oral sex had not led to any cases of HIV transmission. 3 The study also looked at contributing factors that could affect the potential transmission of HIV through oral sex. They monitored viral load and asked questions such as whether ejaculation in the mouth occurred and how good oral health was. Amongst HIV positive men, 34 per cent had ejaculated into the mouths of their partners. Viral load levels were available for 60 people in the study, 10 per cent of whom had levels over 10,000 copies. Nearly 16 per cent of the HIV positive people had CD4 counts below 200. The study, conducted over a ten year period between 1990 and 2000, adds to the growing number of studies which suggest varying levels of risk of HIV transmission from oral sex when compared to anal or vaginal intercourse.
At the 4th International Oral AIDS Conference held in South Africa, the risk of transmission through oral sex was estimated to be approximately 0.04 per cent per contact. 4 This percentage figure is a lot lower than the two American figures, because this figure is a risk per contact percentage, whereas the other figures are percentage risks over much longer time periods. Oral sex is still regarded as a low-risk sexual activity in terms of HIV transmission, but only when more work is done will we be clearer as to the risks of oral sex.
Are there any individual documented cases of HIV transmission during oral sex?
While it is very difficult to ever know how HIV transmission occurred, according to the U.S. Centers for Disease Control and Prevention, there have been a few documented cases of HIV transmission during oral sex. 5
How do I protect myself and my partner during oral sex?
The already low risk of becoming infected with HIV from oral sex can be reduced further by using condoms. Flavoured condoms are available for those who don’t like the taste of latex or spermicide. For cunnilingus or anilingus, a condom cut open or a dental dam (a thin square of latex) can serve as a physical barrier to prevent transmission of HIV and many other STDs.
- 1. UCSF press release (14 August 2001) ' HIV infection from receptive oral sex is a rare event, UCSF study confirms'
- 2. DILLON et. al. (February 2000) 'Primary HIV infections associated with oral transmission', 7th Conference on Retroviruses and Opportunistic Infections, Chicago. Abstract 473
- 3. DEL ROMERO et al. (2002) 'Evaluating the risk of HIV transmission through unprotected orogenital sex', AIDS, Vol.16, p. 1296-1297
- 4. VITTINGHOFF, E et al. (1999) 'Per-contact risk of human immunodeficiency virus transmission between male sexual partners', American Journal of Epidemiology, Vol. 150 No. 3, p.306-11
- 5. CDC 'HIV transmission'