Protect Others

Understanding how HIV is transmitted will help you take steps to protect yourself and others. Someone who has HIV can transmit the virus in the following ways:

• Having sex without a condom.
  • Anal sex is the highest-risk sexual behavior. During anal sex, it is less risky for you as the HIV-positive partner to be the receptive partner (bottom) than the insertive partner (top).
  • Vaginal sex is the second highest-risk sexual behavior.
  • Having multiple sex partners or having other sexually transmitted infections can increase the risk of infection through sex.
• Sharing needles, syringes, rinse water, or other equipment (works) used to prepare injection drugs.

Less commonly, HIV may be spread by:

• Oral sex - using the mouth to stimulate the penis, vagina, or anus (fellatio, cunnilingus, and rimming). Getting fellatio (mouth to penis oral sex) and ejaculating (cum) in your partner’s mouth is riskier than other types of oral sex.
• Being born to a mother living with HIV. HIV can be passed from mother to child during pregnancy, birth, or breastfeeding.
• Being stuck with an HIV-contaminated needle or other sharp object. This is a risk mainly for health care workers.
• A person living with HIV pre-chewing food and giving to another person to eat. The contamination occurs when infected blood from the person living with HIV’s mouth mixes with food while chewing and is very rare.
• A person living with HIV biting another person. Each of the very small number of documented cases has involved severe trauma with extensive tissue damage and the presence of blood. There is no risk of transmission if the skin is not broken.
• Contact between broken skin, wounds, or mucous membranes and HIV-infected blood or blood-contaminated body fluids. These reports have also been extremely rare.
• Deep, open-mouth kissing if the person with HIV has sores or bleeding gums and blood is exchanged. HIV is not spread through saliva. Transmission through kissing alone is extremely rare.

Talk about your HIV status with all of your sexual partners and take steps to protect your health and your partners' health.

The following actions can reduce your risk of transmitting HIV:

• Use antiretroviral therapy (ART). ART reduces the amount of virus (viral load) in your blood and body fluids. ART can keep you healthy for many years, and greatly reduce your chance of transmitting HIV to sex partners if taken consistently and correctly.
• If you are taking ART, follow your health care provider’s advice. Visit your health care provider regularly and always take your medicine as directed.
• Choose less risky sexual behaviors. Oral sex is much less risky than anal or vaginal sex. Anal sex is the highest-risk sexual activity for HIV transmission. Sexual activities that do not involve the potential exchange of body fluids carry no risk for getting HIV (like touching).
• Use condoms consistently and correctly. When used correctly and consistently, condoms are highly effective in preventing HIV infection. Condoms are also effective at preventing sexually transmitted diseases (STDs) transmitted through body fluids, like gonorrhea, chlamydia, and HIV. However, they provide less protection against STDs spread through skin-to-skin contact like human papilloma virus (HPV which can cause genital warts), genital herpes, and syphilis. There are two types of condoms: male and female.
  • Male Condoms
    • Latex condoms provide the best protection against HIV. Polyurethane (plastic) or polyisoprene (synthetic rubber) condoms are good options for people with latex allergies. Natural membrane (such as lambskin) condoms are porous. This means that infections can pass through them, and therefore do not protect as well against HIV and certain other STDs.
    • Lubricants can help prevent condoms from breaking. Water-based and silicon-based lubricants are safe to use with latex condoms. Oil-based lubricants and products containing oil, such as hand lotion, Vaseline, or Crisco should not be used with latex condoms.
  • Female Condoms
    • Female condoms are thin pouches made of a synthetic latex product called nitrile.
    • When worn in the vagina, female condoms are just as effective as male condoms at preventing STDs, HIV and pregnancy. Some people use female condoms for anal sex. However, we do not know how well female condoms prevent HIV and other STDs when used for anal sex. But we do know that HIV cannot travel through the nitrile barrier.
    • It is safe to use any kind of lubricant with nitrile female condoms.
• Talk to your partners about pre-exposure prophylaxis (PrEP), taking HIV medicine daily to prevent HIV infection. PrEP should be considered for HIV-negative partners who are in an ongoing sexual relationship with an HIV-positive partner. PrEP should also be considered for people who are at substantial risk for getting HIV. See CDC’s PrEP web page for more information.
• Talk to your partners about post-exposure prophylaxis (PEP) if you think they have had a possible exposure to HIV. Examples of a possible exposure include you having anal or vaginal sex without a condom, or the condom breaking and your partner is HIV-negative and not on PrEP. Your partner’s chance of exposure to HIV is lower if you are taking ART consistently and correctly, especially if your viral load is undetectable. Your partner’s change of getting HIV is reduced if they start PEP immediately, but no more than 72 hours (3 days) after they may have been exposed to HIV, and take it daily for 4 weeks.
• Get tested and treated for STDs and encourage your partner(s) to do the same. If you are sexually active, get tested at least once a year. STDs can have long-term health consequences. They can also increase the chance of getting HIV or transmitting it to others. Find an STD testing site.

You should also encourage your partners who are HIV-negative to get tested for HIV at least once a year so they are sure about their HIV status and can take action to keep them healthy. To find an HIV testing site near them, they can call 1-800-CDC-INFO (232-4636), visit CDC's testing site locator, text their ZIP code to KNOW IT (566948), or use a home HIV testing kit.

You can also view stories and testimonials of how people living with HIV are protecting their partners on this website.

Pre-exposure prophylaxis (PrEP): “PrEP” stands for Pre-Exposure Prophylaxis. The word “prophylaxis” means to prevent or control the spread of an infection or disease. The goal of PrEP is to prevent HIV infection from taking hold if your partner is exposed to the virus. This is done by taking one pill every day. These are some of the same medicines used to keep the virus under control in people who are already living with HIV.

With 50,000 new HIV infections each year in the United States, and no cure or vaccine available, prevention is key. When taken every day, PrEP can provide a high level of protection against HIV. PrEP is even more effective when it is combined with condoms and other prevention tools.

CDC recommends that PrEP be considered for people who are HIV-negative and at substantial risk for HIV.

For sexual transmission, this includes anyone who is in an ongoing relationship with a partner who is living with HIV.

It also includes anyone who (1) is not in a mutually monogamous* relationship with a partner who recently tested HIV-negative, and (2) is a

• gay or bisexual man who has had anal sex without a condom or has been diagnosed with an STD in the past 6 months; or
• heterosexual man or woman who does not regularly use condoms during sex with partners of unknown HIV status and who are at substantial risk of HIV infection (people who inject drugs or have bisexual male partners).

* Mutually monogamous means that you and your partner only have sex with each other and do not have sex outside the relationship.

For heterosexual couples where one partner has HIV and the other does not, PrEP is one of several options to protect the uninfected partner during conception and pregnancy.

For people who inject drugs, this includes those who have injected illicit drugs in the past 6 months and who have shared injection equipment or been in drug treatment for injection drug use in the past 6 months.

People who use PrEP must be able to take the drug every day and to return to their health care provider every 3 months for a repeat HIV test, prescription refills, and follow-up.

In several studies of PrEP, the risk of getting HIV infection was much lower—up to 92% lower—for those who took the medicines consistently than for those who didn’t take the medicines.

See CDC’s PrEP web page for a brief description of these studies.

Learn more about PrEP by reading CDC’s PrEP 101 factsheet.

Post-exposure prophylaxis (PEP): PEP stands for Post-exposure Prophylaxis. It involves your partner taking antiretroviral medicines as soon as possible, but no more than 72 hours (3 days) after they may have been exposed to HIV, to try to reduce the chance of becoming HIV-positive. These medicines keep HIV from making copies of itself and spreading through their body. Two to three drugs are usually prescribed, and they must be taken for 28 days. PEP is not always effective; it does not guarantee that someone exposed to HIV will not become infected with HIV.

PEP is used for anyone who may have been exposed to HIV very recently during a single event (like unprotected sex, needle-sharing injection drug use, or sexual assault). It is not the right choice for people who may be exposed to HIV frequently. A health care provider will consider whether PEP is right for your partner based on the risk of their exposure.

Keep in mind that PEP should only be used in situations right after a potential HIV exposure. It is not a substitute for regular use of other proven HIV prevention methods, such as pre-exposure prophylaxis (PrEP), correct and consistent condom use, or use of sterile injection drug works.

If your partner is prescribed PEP, they will be asked to return for HIV testing at 4 to 6 weeks, 3 months, and 6 months after the potential exposure to HIV.

PEP must begin within 72 hours of exposure, before the virus has time to make too many copies of itself in the body.

Starting PEP as soon as possible after a potential HIV exposure is important: research has shown that PEP has little or no effect in preventing HIV infection if it is started more than 72 hours after HIV exposure. HIV makes copies of itself once it enters the body, and it takes about 3 days for it to spread through the body. When HIV is only in a few cells where it entered the body, it can sometimes be stopped by PEP. When HIV is in many cells in many places in the body, PEP will not work.

More information about PEP is available from CDC’s PEP 101.