We have learned a lot about how HIV is transmitted. When AIDS first hit our community, no one knew why gay and bisexual men were becoming sick, or how it could be prevented. In the absence of knowledge, people came up with their own theories and prevention methods. Some of them turned out to be useless, and some of them ended up working.

Now that we have much more scientific evidence about HIV/AIDS, we can make decisions about our sex lives that are based on the real risk of HIV transmission, not fear or misinformation.

Here's what we know today...

You can be infected with HIV if you do something that allows enough of the virus to get into your bloodstream from the body fluids of a person who is HIV-positive.

There are only five everyday body fluids that have enough HIV in them to infect someone:

• blood
• semen (cum and pre-cum
• vaginal fluids (including menstrual fluids
• breast milk
• rectal fluids*

In order for transmission to occur, one of these fluids must come into contact with an entry point into the bloodstream in the HIV-negative person: a cut or abrasion on the skin, or the mucous membranes (internal lining) inside the body.

* What are rectal fluids and why have I never seen this before?
Rectal fluids are the fluids that cover the inside of the ass, and are the body's natural form of anal lubrication. You may not have seen this listed before, because it's only recently that research has demonstrated how HIV infection happens inside the ass.

The lining of the rectum contains a thin layer with many immune cells – the very cells that HIV likes to target. The concentration of HIV in this thin layer can be higher than in blood, semen or vaginal secretions, making infection more likely. When another STI is present, the amount of HIV can be even higher in this part of the body.

 What else is new in HIV transmission?

We used to think that in order for HIV to get into the bloodstream, there needed to be a tear in the mucosal lining. This is true, but we now know that the virus can also be transmitted directly through mucosal linings. This means that HIV can enter the bloodstream through the inside of your ass, under the foreskin or through the urethra (the tube we pee through) - even when there is no tear. The inside of the mouth has mucosal lining as well, but has fewer of the immune cells that HIV likes to target, so oral sex is still a low risk activity even when semen (cum) gets in the mouth.

 Sexually transmitted infections (STIs)

We also know more about the role STIs play in getting infected with HIV through mucosal linings. An STI can cause tears as well as swelling and inflammation of these linings. This swelling is a response from your immune system, which means there is an increase in the immune cells that HIV likes to target - making you more likely to get infected with HIV this way.

 Risk of HIV transmission for sexual activities.

Based on this information, sexual activities are categorized into four groups in Canada based on risk of HIV transmission: high risk, low risk, negligible risk, and no risk.

Remember that these risk levels only apply to HIV, so the risk of transmitting another STI (syphilis, hepatitis, parasites, etc.) may be higher or lower than the risk levels outlined below. And if you are HIV-positive, your risk levels for other STIs are generally higher, including sexual transmission of hepatitis C.

 Fucking (anal sex, vaginal sex, frontal sex)

• Top or bottom, without a condom = high risk
• Top or bottom, with a condom = low risk*

 Oral sex (blowjobs, fellatio, cunnilingus)

• Giving with a condom = negligible risk
• Giving without a condom and taking cum or pre-cum or vaginal fluids in the mouth = low risk
• Receiving, with or without a condom = negligible risk**

 Kissing

• Wet or dry kissing = no risk
• Wet kissing with exchange of blood = low risk

 Rimming (anilingus, eating ass)

• Giving or receiving, with or without a barrier = negligible risk
• Fingering Giving or receiving, with or without a glove = negligible risk

 Handjobs (masturbation by a partner)

• Giving or receiving, with or without a glove = no risk

 Sharing sex toys (dildos, vibrators, butt plugs, anal beads, etc.)

• Inserting a shared toy, no condom = high risk
• Inserting a shared toy, with a condom = negligible risk
• Inserting a disinfected toy = negligible risk

 Fisting

• Giving or receiving, with or without a glove = negligible risk

 Watersports, scat (urine/piss, feces/shit)

• Receiving on the body = no risk
• Receiving into the body = negligible risk (the risk is due to the potential presence of blood)

* Why is fucking with a condom considered low-risk?
Using a condom correctly and consistently has a negligible risk for HIV transmission. However, there are enough instances of a condom breaking, slipping, or somehow being used improperly, which led to transmission of the virus. For this reason, fucking with a condom needs to be classified as "low risk".

** What does "negligible risk" mean?
"Negligible risk" is not the same as "no risk"; it means there is a theoretical possibility of HIV transmission, but there are no known cases of the virus being transmitted this way.

To see HIV transmission risk levels for non-sexual and other activities, see the Canadian AIDS Society's HIV Transmission: Guidelines for Assessing Risk.