Preventing HIV Transmission

How is HIV transmitted?

HIV is transmitted (spread) through the blood, semen, genital fluids, or breast milk of an infected person. The spread of the virus is called HIV transmission. The most common ways people become infected with HIV are by:

• Having unprotected sex with a person infected with HIV
• Sharing drug needles or syringes with a person infected with HIV

Women infected with HIV can transmit the virus to their babies during pregnancy or childbirth or by breastfeeding. If you are a woman who has HIV, talk to your health care provider about ways to prevent pregnancy. And if you are pregnant or plan to become pregnant, ask your health care provider how you can protect your baby from HIV. (See the HIV and Pregnancy fact sheets.)

I am taking anti-HIV medications and my viral load is undetectable. Can I still infect another person with HIV?

Your anti-HIV medications are doing a good job of controlling your infection. The amount of HIV in your blood is so low that a viral load test can't detect the virus. However, having an undetectable viral load doesn't mean you're cured. You still have HIV. And although having an undetectable viral load reduces the risk of HIV transmission, you can still infect another person with the virus.

How can I prevent transmitting HIV?

To prevent infecting another person with HIV:

• Use a condom every time you have sex.
• If you inject drugs, don't share your needles or syringes.
• Don't share your razor, toothbrush, or other items that may have your blood on them.
• Take your anti-HIV medications according to your health care provider's directions.
• If you are a mother infected with HIV, don't breastfeed your baby.

Talk to your health care provider about how HIV is transmitted and ways to prevent spreading the virus. At each visit, discuss any high-risk behaviors (such as having unprotected sex or sharing drug needles) with your health care provider. Talking about high-risk behaviors can be difficult. And making changes, even when we want to, isn't always easy. However, it's important to be honest with your health care provider about any high-risk activities. Discussing ways to prevent HIV transmission can reduce your chances of infecting another person with the virus.

Can I put my partner who is also infected with HIV at risk?

It's important to use condoms and not share drug needles even if your partner is also infected with HIV. You and your partner may have different strains of the virus. Your partner's HIV could act differently in your body or cause the anti-HIV medications you take to be less effective. And your strain of HIV could have the same effects on your partner.

Where can I find more information about HIV prevention?

The Centers for Disease Control and Prevention (CDC) National Prevention Information Network (NPIN) provides information about prevention of HIV infection, other sexually transmitted infections (STIs), and tuberculosis (TB).

If you have questions about HIV transmission, call CDCINFO at 1–800–232–4636 or visit www.cdc.gov/hiv/.

For More Information

Contact an AIDSinfo health information specialist at 1–800–448–0440 or visit http://aidsinfo.nih.gov. See your health care provider for medical advice.

This information is based on the U.S. Department of Health and Human Services' Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents (available at http://aidsinfo.nih.gov/Guidelines/).