[beachboy]

1. How risky is oral sex as compared to anal sex?

Oral sex is considered less risky for several reasons. First, the mucus membrane lining the mouth is much tougher, thicker, and more resilient than the anal canal, so it is more difficult for HIV to break through. Also, it is easier to remove infectious fluids from the mouth than from the anal canal. To remove precome or semen from the mouth after oral sex, a person can spit out the semen precome and gargle with water, mouthwash, hydrogen peroxide, or alcohol. (We recommend spitting and/or gargling instead of swallowing, just in case the semen, precome, or penile fluids contain blood or other agents such as gonorrhea or chlamydia which can infect the throat.) Finally, recent reports in the scientific literature say that saliva in the mouth contains enzymes which can help neutralize the virus.



2. How risky is insertive oral sex as compared to receptive oral sex?

Receptive oral sex or "giving a blow job" is considered more risky because of the potential that more HIV-infected fluid will enter the body. When someone is giving a blow job, not only is there the potential exposure to semen and precome, there is also the potential exposure to blood from a penile cut, sore, or abrasion, or even from an irritated piercing.

Furthermore, if the man receiving the blow job has another infection in addition to HIV, he may have an unusually high level of HIV present in his body fluids. This is because his immune system may not be as efficient at controlling, HIV since it is also trying to contain the other virus or bacteria. An added problem is that if the additional infection is localized in the penis, then there will probably be urethra inflammation. If so, his penile fluids may contain high levels of 'infection-fighting" white blood cells, which unfortunately also contain HIV. All this could amount to increased infectiousness.

Getting a blow job is considered a very low risk sexual activity. In general, if someone is getting a blow job and has no cuts, scratches or sores on his penis, the possibility of his being exposed to HIV is lower. If the man giving the blow job has good oral hygiene and his mouth is free of infection, then the inserter's penis is primarily being exposed only to saliva. Getting a blow job might also be safer than giving one because ejaculating might flush out the virus. Urinating and washing the penis also reduce the chances of HIV infection and of additional infection.

All this notwithstanding, it is still possible that someone's penis might be exposed to blood or other HIV-infected fluids during a blow job. This might occur if someone has an abrasion or scrape in his mouth which might bleed or if for example, during multiple-partner sex (group sex), he carries in his mouth the remnants of another person's penile fluids or blood from one blow job to the next.

3. Is precum infectious? If so, is it as infectious as semen?

Two studies have isolated HIV from precome but the potential for HIV infection from precome is most likely minimal under normal circumstances. Exposure to precome probably poses less risk of HIV infection than exposure to semen for two reasons: it has fewer infectious particles of HIV per milliliter than semen and even if a lot of precome is discharged into the mouth during oral sex, it is still less than the amount of semen the mouth or throat is exposed to by an ejaculation.

Now, onto the main discussion. There are two sides to the phenomenon of how supposedly "low-risk" oral sex becomes a high-risk activity resulting in infection: the infectiousness of the HIV-positive partner, and the susceptibility of the HIV-negative partner. I would like to go through the important factors involved in each side of the general phenomenon of ncreased-risk oral sex, and then to report our study data specifically.

There are at least five important factors involved in susceptibility to HIV infection through oral sex.

1. A person's genetics, immune system and biological history. Some individuals may have an increased susceptibility due to these factors. Some people, for example, are prone to chronic allergies such as "hay fever." During outbreaks of these allergies, the immune system is activated. The tissue lining of the throat and nasal passage might become inflamed and therefore more permeable to HIV. Also, if someone with an allergy outbreak is constantly blowing his nose, then irritation and bleeding are more likely to occur, which might create a possible route for HIV to enter his system.

I spoke with one man who believed he became infected with HIV by getting a blow job. He told me that he had a history of picking up STDs in the past from insertive oral sex, claiming to have been infected with urethral gonorrhea this way, as well. We can speculate that either due to his genetics, immune system, or some other biological factors, he was not sufficiently resistant to STDs, including HIV, when exposed during insertive oral sex.

2. Oral hygiene. First of all, most Americans across the board have lousy oral hygiene, so this factor may play less of a differentiating role than we might think. Nonetheless, if you have poor oral hygiene or are suffering from gingivitis, receding gums or periodontal disease, or have recently had oral surgery, you may be at increased risk since the virus may more readily find a port of entry into your body. Also, while it is advisable to brush and floss your teeth regularly for excellent oral hygiene, it is probably best not to engage in receptive oral sex for a few hours after flossing or heavy brushing, just in case this leaves abrasions on your gums or mucus membrane.

3. Other infection. You may be at increased susceptibility to HIV if you already have another infection or if you are exposed to HIV and another infection simultaneously. This may be true whether the infection in systemic (such as hepatitis) or localized in your mouth and/or throat (such as gonorrhea or chlamydia.) The reason a systemic infection like hepatitis may increase susceptibility is that if HIV gains entry into your body, your immune system may not be able to fully focus its power against HIV, either because it may already be trying to control another infectious agent or because it may be trying to combat two new infectious agents simultaneously. The reason a localized infection such as gonorrhea or chlamydia might increase your susceptibility to HIV infection is that the tissue lining in your mouth, throat and/or nasal passage might be inflamed, irritated, or abraded by the infectious agent, and so would be an easier target for HIV.

With both systemic and localized infections, another factor which might heighten your susceptibility is the increased amount of lymphocytes in your blood. Lymphocytes are a type of white blood cell activated during infection. Unfortunately, they are also a major target for HIV infection, and it may be easier for the HIV viral particle to locate a susceptible lymphocyte during a period when they are activated due to another infection. The same principle may also apply to other infectious agents such as a cold, flu, strep, staph, as well as to nasal and throat inflammation due to chronic allergies. In general, times when you are feeling run down are times to be more careful.

4. Drug use. The most important factor of drug use is probably the effect the drug has on a person's behavior during sex. Sex on a stimulant such as cocaine, speed, or poppers is likely to be more vigorous, prolonged and intense. Sex may also be prolonged because, on certain drugs, it can take longer to reach orgasm.

Furthermore, during sex on drugs, a person may get caught up in the moment and thus may not notice the wear and tear to his penis and/or throat. He may also be able to ignore any pain that he does feel until after the sex is completed. Study participants do report that, while on speed, the heightened sexual experience and sense of well-being take precedence over everything else--including the concern about being safe.

Study participants also report that popper use makes it easier to engage in rougher or more penetrative sex such as "deep-throating," especially if their sex partner has a large penis. In these situations, the tissue of the throat is more likely to become irritated, especially if the sex is prolonged. Moreover, there has been scientific speculation that popper use causes a dilation of the blood vessels and thus increases the risk of HIV transmission. The biological theory is that if HIV enters the tissue during the "rush" when the mucus membrane lining the mouth and throat is engorged with blood, then the virus more easily locates a white blood cell or lymphocyte to infect. finally, some scientists also believe that certain recreational drugs, such as popper can temporarily suppress the immune system and so increase a person's susceptibility to infection if exposed.

5. Recent immunization against an infection. The immune cells of seven out of ten HIV- uninfected individuals were more easily infected in the test tube after immunization than before immunization, the National Institute of Allergy and Infectious Diseases (NIAID) reported in a recent issue of "The New England Journal of Medicine." The immunization studied was the tetanus booster shot. During the temporary immune system activation which the immunization shot normally causes, the HIV-uninfected individual may be at increased susceptibility to HIV infection via unprotected anal or oral sex (with an infected partner) the study suggests. This enhanced susceptibility may last for several weeks after the immunization.