The Basics of HIV Prevention
Last Reviewed: April 29, 2019
- HIV is spread only in certain body fluids from a person who has HIV. These fluids are blood, semen, pre-seminal fluids, rectal fluids, vaginal fluids, and breast milk.
- In the United States, HIV is spread mainly by having sex or sharing injection drug equipment, such as needles, with someone who has HIV.
- To reduce your risk of HIV infection, use condoms correctly every time you have sex. Don’t inject drugs. If you do, use only sterile injection equipment and water and never share your equipment with others.
- If you don’t have HIV but are at high risk of becoming infected with HIV, talk to your health care provider about pre-exposure prophylaxis (PrEP). PrEP involves taking a specific HIV medicine every day to reduce the risk of HIV infection.
How is HIV spread?
The person-to-person spread of HIV is called HIV transmission. HIV is spread only in certain body fluids from a person who has HIV:
- Pre-seminal fluids
- Rectal fluids
- Vaginal fluids
- Breast milk
HIV transmission is only possible if these fluids come in contact with a mucous membrane or damaged tissue or are directly injected into the bloodstream (from a needle or syringe). Mucous membranes are found inside the rectum, the vagina, the opening of the penis, and the mouth.
In the United States, HIV is spread mainly by:
- Having anal or vaginal sex with someone who has HIV without using a condom or taking medicines to prevent or treat HIV
- Sharing injection drug equipment (works), such as needles, with someone who has HIV
HIV can also spread from a woman with HIV to her child during pregnancy, childbirth (also called labor and delivery), or breastfeeding. This is called mother-to-child transmission of HIV.
In the past, some people were infected with HIV after receiving a blood transfusion or organ or tissue transplant from a donor with HIV. Today, this risk is very low because donated blood, organs, and tissues are carefully tested in the United States.
You can't get HIV from casual contact with a person who has HIV, such as a handshake, a hug, or a closed-mouth kiss. And you can't get HIV from contact with objects such as toilet seats, doorknobs, or dishes used by a person who has HIV. Use the AIDSinfo You Can Safely Share…With Someone With HIV infographic to spread this message.
How can I reduce my risk of getting HIV?
Anyone can get HIV, but you can take steps to protect yourself from HIV infection.
- Get tested and know your partner’s HIV status. Talk to your partner about HIV testing and get tested before you have sex. Use this testing locator from the Centers for Disease Control and Prevention (CDC) to find an HIV testing location near you.
- Choose less risky sexual behaviors. HIV is mainly spread by having anal or vaginal sex without a condom or without taking medicines to prevent or treat HIV.
- Use condoms. Use a condom correctly every time you have sex. Read this fact sheet from CDC on how to use condoms correctly.
- Limit your number of sexual partners. The more partners you have, the more likely you are to have a partner with poorly controlled HIV or to have a partner with a sexually transmitted disease (STD). Both of these factors can increase the risk of HIV transmission.
- Get tested and treated for STDs. Insist that your partners get tested and treated, too. Having an STD can increase your risk of becoming infected with HIV or spreading it to others.
- Talk to your health care provider about pre-exposure prophylaxis (PrEP). PrEP is an HIV prevention option for people who don't have HIV but who are at high risk of becoming infected with HIV. PrEP involves taking a specific HIV medicine every day. For more information, read the AIDSinfo fact sheet on Pre-Exposure Prophylaxis (PrEP).
- Don't inject drugs. But if you do, use only sterile drug injection equipment and water and never share your equipment with others.
I am HIV positive but my partner is HIV negative. How can I protect my partner from HIV?
Take HIV medicines daily. Treatment with HIV medicines (called antiretroviral therapy or ART) helps people with HIV live longer, healthier lives. ART can't cure HIV infection, but it can reduce the amount of HIV in the body (also called the viral load). One of the main goals of ART is to reduce a person's viral load to an undetectable level. An undetectable viral load means that the level of HIV in the blood is too low to be detected by a viral load test. People with HIV who maintain an undetectable viral load have effectively no risk of transmitting HIV to their HIV-negative partner through sex.
Here are some other steps you can take to protect your partner from HIV:
- Use condoms correctly every time you have sex.
- Talk to your partner about taking PrEP.
- If you inject drugs, don't share your needles, syringes, or other drug equipment with your partner.
Are HIV medicines used in other situations to prevent HIV infection?
Yes, HIV medicines are also used for post-exposure prophylaxis (PEP) and to prevent mother-to-child transmission of HIV.
- Post-exposure prophylaxis (PEP)
PEP involves taking HIV medicines soon after a possible exposure to HIV to prevent becoming infected with HIV. PEP may be used, for example, after a person has sex without a condom with a person who has HIV or after a health care worker is accidentally exposed to HIV in the workplace. To be effective, PEP must be started within 72 hours (3 days) after the possible exposure to HIV. PEP involves taking HIV medicines each day for 28 days. For more information, read the AIDSinfo fact sheet on Post-Exposure Prophylaxis (PEP).
- Prevention of mother-to-child transmission of HIV
Women with HIV take HIV medicines during pregnancy and childbirth to reduce the risk of passing HIV to their babies and to protect their own health. Their newborn babies also receive HIV medicine for 4 to 6 weeks after birth. The HIV medicine reduces the risk of infection from any HIV that may have entered a baby’s body during childbirth. For more information, read the AIDSinfo fact sheet on Preventing Mother-to-Child Transmission of HIV.
This fact sheet is based on information from the following sources:
From the Department of Health and Human Services:
- Recommendations for the Use of Antiretroviral Drugs in Pregnant Women with HIV Infection and Interventions to Reduce Perinatal HIV Transmission in the United States:
- General Principles Regarding Use of Antiretroviral Drugs During Pregnancy: Overview
- Management of Infants Born to Women with HIV Infection: Antiretroviral Management of Newborns with Perinatal HIV Exposure or Perinatal HIV
- Call 1-800-448-0440
- (1 p.m. to 4 p.m. ET)
- Send us an email