Yes, it is possible for either partner to become infected with HIV through performing or receiving oral sex. There have been a few cases of HIV transmission from performing oral sex on a person infected with HIV. While no one knows exactly what the degree of risk is, evidence suggests that the risk is less than that of unprotected anal or vaginal sex.

If the person performing oral sex has HIV, blood from their mouth may enter the body of the person receiving oral sex through

• the lining of the urethra (the opening at the tip of the penis);
• the lining of the vagina or cervix;
• the lining of the anus; or
• directly into the body through small cuts or open sores.

If the person receiving oral sex has HIV, their blood, semen (cum), pre-seminal fluid (pre-cum), or vaginal fluid may contain the virus. Cells lining the mouth of the person performing oral sex may allow HIV to enter their body.

The risk of HIV transmission increases

• if the person performing oral sex has cuts or sores around or in their mouth or throat;
• if the person receiving oral sex ejaculates in the mouth of the person performing oral sex; or
• if the person receiving oral sex has another sexually transmitted disease (STD).

Not having (abstaining from) sex is the most effective way to avoid HIV.

If you choose to perform oral sex, and your partner is male,

• use a latex condom on the penis; or
• if you or your partner is allergic to latex, plastic (polyurethane) condoms can be used.

Studies have shown that latex condoms are very effective, though not perfect, in preventing HIV transmission when used correctly and consistently. If either partner is allergic to latex, plastic (polyurethane) condoms for either the male or female can be used. For more information about latex condoms, see "Male Latex Condoms and Sexually Transmitted Diseases."

If you choose to have oral sex, and your partner is female,

• use a latex barrier (such as a natural rubber latex sheet, a dental dam or a cut-open condom that makes a square) between your mouth and the vagina. A latex barrier such as a dental dam reduces the risk of blood or vaginal fluids entering your mouth. Plastic food wrap also can be used as a barrier.

If you choose to perform oral sex with either a male or female partner and this sex includes oral contact with your partners anus (analingus or rimming),

• use a latex barrier (such as a natural rubber latex sheet, a dental dam or a cut-open condom that makes a square) between your mouth and the anus. Plastic food wrap also can be used as a barrier.

If you choose to share sex toys with your partner, such as dildos or vibrators,

• each partner should use a new condom on the sex toy; and
• be sure to clean sex toys between each use.

(Courtesy CDC, Atlanta Georgia)
For more information visit: http://www.cdc.gov/hiv/pubs/faqs.htm

Oral Sex and the Risk of HIV Transmission
(Courtesy: www.avert.org)

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, bleeding gums, genital sores, 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 cum. No-one became HIV positive during the study. Due to the low number of unprotected serodiscordant pairings, all that can be said is that there was a less than 2.8 per cent chance of infection through oral sex over a year. 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. However, the results of the study have since been called into question due to the reliability of the participant's data.

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 lead to any cases of HIV transmission. The study also looked at contributing factors that could effect 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. 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.

Theoretical and Documented Risk of HIV Transmission During Oral-Penile Contact

Theoretical:

In fellatio, there is a theoretical risk of transmission for the receptive partner (the person who is sucking) because infected pre-ejaculate ("pre-cum") fluid or semen can get into the mouth. For the insertive partner (the person who is being sucked), there is a theoretical risk of infection because infected blood from a partner's bleeding gums or an open sore could come in contact with a scratch, cut, or sore on the penis.

Documented:

Although the risk is many times smaller than anal or vaginal sex, HIV has been transmitted to receptive partners through fellatio, even in cases when insertive partners didn't ejaculate ("cum")

Theoretical and Documented Risk of HIV Transmission During Oral-Vaginal Contact

Theoretical:

Cunnilingus carries a theoretical risk of HIV transmission for the insertive partner (the person who is licking or sucking the vaginal area) because infected vaginal fluids and blood can get into the mouth. (This includes, but is not limited to, menstrual blood.) Likewise, there is a theoretical risk of HIV transmission during cunnilingus for the receptive partner (the person who is having her vagina licked or sucked) if infected blood from oral sores or bleeding gums comes into contact with vulvar or vaginal cuts or sores.

Documented:

The risk of HIV transmission during cunnilingus is extremely low compared to vaginal and anal sex. However, there have been a few cases of HIV transmission most likely resulting from oral-vaginal sex.

Theoretical and Documented Risk of HIV Transmission During Oral-Anal Contact

Theoretical:

Anilingus carries a theoretical risk of transmission for the insertive partner (the person who is licking or sucking the anus) if there is exposure to infected blood, either through bloody fecal matter (bodily waste) or cuts/sores in the anal area. Anilingus carries a theoretical risk to the receptive partner (the person who is being licked/sucked) if infected blood in saliva comes in contact with anal/rectal lining.

Documented:

There has been one published case of HIV transmission associated with oral-anal sexual contact.

Other STDs Can Also Be Transmitted Through Oral Sex

Scientists have documented a number of other sexually transmitted diseases that have also been transmitted through oral sex. Herpes, syphilis, gonorrhea, genital warts (HPV), intestinal parasites (amebiasis), and hepatitis A are examples of STDs which can be transmitted during oral sex with an infected partner.

 for more information http://www.avert.org/orlsx.htm