HIV was established as the cause of AIDS in 1983. Since then, we’ve learned a great deal about the ways HIV can—and cannot—be transmitted. This fact sheet provides information regarding HIV transmission but should not be consulted as an alternative to medical care and testing. If you fear that you have been exposed to HIV—regardless of how low the perceived risk and no matter how much info you find elsewhere—you need to get in touch with your health care provider or an HIV testing center and be tested for HIV.
How is HIV transmitted?
HIV is found in semen, vaginal fluids, blood and breast milk. It enters the body through open cuts, sores or breaks in the skin; through mucous membranes, such as those inside the anus or vagina; or through direct injection. There are several ways HIV is transmitted:
- Anal or vaginal intercourse without a condom with a partner who is either positive or doesn’t know their status. Oral sex is not an efficient route of HIV transmission, but HIV can be spread this way. Kissing, masturbation and “hand jobs” do not spread HIV.
- Sharing needles, syringes or other injection equipment with someone who is HIV positive or doesn’t know their status.
- Babies born to HIV-positive women can be infected with the virus before or during birth, or through breast feeding after birth.
- Health care professionals have been infected with HIV in the workplace, usually after being stuck with needles or sharp objects containing HIV-infected blood. As for HIV-positive health care providers infecting their patients, the risk is exceedingly low
- HIV can be transmitted via donated blood or blood-clotting procedures. However, this is now very rare in countries like the U.S. where blood is screened before use.
HIV has been detected in saliva, tears and urine but only in extremely low concentrations. And there hasn’t been a single report of HIV transmission through these fluids. HIV cannot be transmitted through activities such as shaking hands, hugging or kissing. You cannot become infected from a toilet seat, towels, sheets, drinking fountain or sharing food or eating utensils with someone who is positive. It is, however, advised not to share toothbrushes or razors with people who are HIV positive. You also cannot get HIV from mosquitoes.
How can HIV transmission be prevented?
Not having sex (abstinence), or having sex only in a monogamous relationship with a partner you know is uninfected, are the surest ways to avoid HIV infection. But if you are sexually active—or injecting drugs—consider the following:
- Get tested for HIV. Approximately 25 percent of HIV-positive people in the U.S. don’t know they’re infected. Know your status to protect your health—and the health of others.
- Practice safer sex. Condoms and lubricant, used correctly and consistently, can greatly reduce the risk of HIV and other sexually transmitted infections when having vaginal or anal intercourse with a partner who is HIV positive or with someone whose HIV status isn’t certain.
- Reduce drug-injection risk. If you inject drugs, never share needles, syringes or other “works.” If unused injection equipment is not available, be sure to clean shared needles, syringes and other works with bleach and water.
- If you’re pregnant—or are thinking of starting a family—get tested for HIV. If you’re positive, careful prenatal care, including the use of HIV medications for the mother, can greatly reduce the risk of passing the virus on to the baby to 2 percent or less chance.
Whether you’re HIV positive or negative, prevention is everyone’s responsibility.
- Communicate: If you can’t be sure of your partner’s status, discuss HIV and safer sex before being intimate.
- Keep ’em handy: If you’re sexually active, consider carrying condoms with you—just in case.
- Condom sense: Condoms expire, just like milk, and they’re sensitive to high heat. Keep condoms away from heat and sun and check the dates stamped on them. Also, keep them in places where they cannot be punctured.
- No nonoxynol-9: Condoms containing the spermicide nonoxynol-9 may actually increase the risk of HIV transmission.
- Sober advice: Getting drunk or high may cause you to take risks you wouldn’t if you were sober.
Last Reviewed: January 31, 2016