Prevention:

1. See the article on safe sex to learn how to reduce the chance of catching or spreading HIV, and other sexually transmitted diseases.
2. Do not use illicit drugs and 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. These programs can also provide referrals for addiction treatment.
3. Avoid contact with another person's blood. You may need to wear protective clothing, masks, and goggles 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. Infected people should tell any sexual partner about their HIV-positive status. They should not exchange body fluids during sexual activity, and should use preventive measures (such as condoms) to reduce the rate of transmission.
5. HIV-positive women who wish to become pregnant should seek counseling about the risk to their unborn child, and methods to help prevent their baby from becoming infected. The use of certain medications dramatically reduces the chances that the baby will become infected during pregnancy.
6. The Public Health Service recommends that HIV-infected women in the United States avoid breast-feeding to prevent transmitting HIV to their infants through breast milk.
7. Safer sex practices, such as latex condoms, are highly effective in preventing HIV transmission. HOWEVER, there is 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 receiving unprotected anal intercourse. The least risky sexual behavior is receiving oral sex. There is some risk of HIV transmission when performing oral sex on a man, 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 has a low risk of transmission.

HIV-positive patients who are taking antiretroviral 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 their baby less than 1% of the time, compared with 13% to 40% of the time if medications are not used.

The U.S. 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.

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 it has been used to prevent transmission in health care workers injured by needlesticks.

There is less information available about how effective PEP is for people exposed to HIV through sexual activity or injection drug use, but it appears to be effective. If you believe you have been exposed, discuss the possibility with a knowledgeable specialist (check local AIDS organizations for the latest information) as soon as possible. Anyone who has been sexually assaulted should consider the potential risks and benefits of PEP.