Many people still misunderstand how HIV is passed from one person to another. Knowing the basics helps you avoid getting the virus if you are HIV-negative, and avoid giving it to someone else if you are HIV+.

HIV is spread through the following body fluids:

• Blood (including menstrual blood)
• Semen and other male sexual fluids ("pre-cum")
• Vaginal fluids
• Breast milk

HIV is not spread through these body fluids:

• Sweat
• Tears
• Saliva (spit)

The spread of HIV can be prevented! There are ways to avoid, or at least reduce, contact with body fluids that spread HIV. This info sheet explains how.

In the past, HIV was spread by transfusion with blood products, such as whole blood or the "factor" used by hemophiliacs. Many people were infected this way. The blood supply is now much more strictly tested and controlled. The odds of being infected from receiving blood or blood factor in the US are very low.

You cannot get HIV from donating blood – a new, sterile (clean) needle is used for each donation.

Some people, primarily healthcare workers, are infected through needle sticks with infected blood, or through other medical accidents. This is a very small percentage of overall infections.

Today, the most common ways HIV is passed from one person to another are:

• Re-using and sharing needles for injecting drugs (including steroids or hormones)
• Unprotected/unsafe sex (no condoms or other barrier devices)
• Mother-to-child (during pregnancy, birth, or breast-feeding)

Many HIV infections occur when people share needles to inject heroin, methamphetamine, steroids, hormones, or other drugs. This risk may be reduced by cleaning needles with a bleach solution before re-using them. However, some experts question how effective this method really is in reducing transmission.

It is best to use fresh needles each time. This eliminates any risk of infection. Many cities offer free needle exchange programs.

Tattoos or body piercings should always be done by a licensed professional whose equipment is autoclaved, not just "sterilized" with alcohol.

Every sexual act (oral, anal, or vaginal) that involves sexual fluids of some kind has at least some risk. Barriers, such as condoms (male and female), dental dams (thin squares of latex), and latex gloves help reduce risk substantially.

Unsafe sex (sex without condoms or barriers) puts you and your partner at risk for HIV or other sexually transmitted diseases (STDs).

Safer sex (sex using condoms or other barriers correctly and consistently) protects you and your partner.

Listed from most to least risky:

1. Receptive anal sex ("bottoming"): This remains the most risky activity, due to the likelihood of small tears in the rectum allowing semen to have direct contact with the bloodstream. But penetrative anal sex ("topping") can result in HIV transmission, too.
2. Vaginal intercourse: This puts both partners at risk, but HIV is transmitted from men to women much more easily than from women to men.
3. Oral sex: This can be risky for the person performing it, particularly if he or she swallows semen, vaginal fluids, or menstrual fluids.
4. Sharing sex toys without sterilizing them: This can allow HIV to be transmitted from one partner to the next one who uses the toy.
5. Rimming (licking the anus): This is very unlikely to result in HIV infection.
6. Mutual masturbation (hand jobs) and fisting (using a hand to penetrate the anus or vagina): These are relatively low risk, as long as your hand has no open cuts or sores.
   

Sexual assault or rape can result in infection if the attacker is HIV+. The risk increases when rape involves anal penetration, force, and/or multiple attackers. Some forced sexual acts involving wounds can place a victim at very high risk.

In major cities, PEP (post-exposure prophylaxis) is often offered to victims of sexual assault or rape. This month-long treatment with HIV drugs reduces the likelihood of HIV infection substantially. It is currently only used on a regular basis for victims of sexual assault and for healthcare workers who have been exposed to HIV on the job. PEP must be started as quickly as possible, always within 72 hours of the exposure.

HIV+ mothers can pass the virus to their babies while pregnant, during birth, or by breastfeeding. Medical care and HIV drugs given during pregnancy can almost eliminate the risk of a baby getting HIV from its mother. HIV+ mothers should not breastfeed their babies.

There are a few isolated cases of people becoming infected from using a razor that had just been used by an HIV+ person, or from using a toothbrush immediately after the toothbrush was used by someone who was HIV+, or in other unexpected ways. To be safe, always avoid direct contact with blood and sexual fluids in any context.

Don't worry too much about rare cases. For instance, there is one documented case of transmission from deep or "French" kissing – in two people who had terrible dental problems. However, the odds of getting HIV from kissing, even when one person is HIV+, are less than the odds of being struck by lightning.

HIV cannot be transmitted except when certain body fluids are exchanged. You can greatly reduce the risk of transmission by:

• Avoiding contact with sexual fluids by always practicing safer sex
• Abstaining from sex unless you and your partner are both HIV-negative and in a long-term, monogamous relationship
• Not injecting drugs, or if you do, always using new or clean needles
• Finding out your HIV status if you are planning to get pregnant and working with a knowledgeable health care provider and obstetrician if you are HIV+

If you protect yourself in these ways, you do not need to be afraid of getting or passing HIV by casual contact. Remember, HIV is not transmitted by:

• Hugs
• Dancing
• Sharing food or drinks
• Using a shower, bath, or bed used by an HIV+ person
• Kissing (between people with no significant dental problems)
• Sharing exercise equipment
• Bug bites