1. See the article on safe sex to learn how to reduce the chance of acquiring or spreading HIV, and other sexually transmitted diseases.
2. Do not use injected drugs. If IV drugs are used, do not share needles or syringes. Many communities now have needle exchange programs, where you can get rid of used syringes and get new, sterile ones for free. These programs can also provide referrals to addiction treatment.
3. Avoid contact with another person's blood. Protective clothing, masks, and goggles may be appropriate when caring for people who are injured.
4. Anyone who tests positive for HIV can pass the disease to others and should not donate blood, plasma, body organs, or sperm. An infected person should tell any prospective sexual partner about their HIV-positive status. They should not exchange body fluids during sexual activity, and should use whatever preventive measures (such as condoms) will give the partner the most protection.
5. HIV-positive women who wish to become pregnant should seek counseling about the risk to unborn children, and medical advances that may help prevent the fetus from becoming infected. Use of certain medications can dramatically reduce the chances that the baby will become infected during pregnancy.
6. Mothers who are HIV-positive should not breast feed their babies.
7. Safe-sex practices, such as latex condoms, are highly effective in preventing HIV transmission. HOWEVER, there remains a risk of acquiring the infection even with the use of condoms. Abstinence is the only sure way to prevent sexual transmission of HIV.

The riskiest sexual behavior is unprotected receptive anal intercourse -- the least risky sexual behavior is receiving oral sex. Performing oral sex on a man is associated with some risk of HIV transmission, but this is less risky than unprotected vaginal intercourse. Female-to-male transmission of the virus is much less likely than male-to-female transmission. Performing oral sex on a woman who does not have her period carries low risk of transmission.

HIV-positive patients who are taking anti-retroviral medications are less likely to transmit the virus. For example, pregnant women who are on effective treatment at the time of delivery, and who have undetectable viral loads, give HIV to the infant less than 1% of the time, compared with about 20% of the time if medications are not used.

The US blood supply is among the safest in the world. Nearly all people infected with HIV through blood transfusions received those transfusions before 1985, the year HIV testing began for all donated blood. In 2000, according to the American Red Cross, the risk of infection with HIV through a blood transfusion or blood products was 1 in 2,135,000 in the United States.

If you believe you have been exposed to HIV, seek medical attention IMMEDIATELY. There is some evidence that an immediate course of antiviral drugs can reduce the chances that you will be infected. This is called post-exposure prophylaxis (PEP), and has been used to treat health care workers injured by needlesticks, to prevent transmission.

There is less information available about how effective PEP is for people exposed to HIV through sexual activity or IV drug use. However, if you believe you have been exposed, you should discuss the possibility with a knowledgeable specialist (check local AIDS organizations for the latest information) as soon as possible. Anyone who has been raped should be offered PEP and should consider its potential risks and benefits.