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How HIV does—and doesn't—spread

Human immunodeficiency virus (HIV) doesn't spread through handshakes or hugs. When you know how it really does spread, you're best prepared to protect yourself.

Misleading rumors abound about how HIV, the virus that causes AIDS, spreads. That's why the Centers for Disease Control and Prevention (CDC) works to educate the public about how HIV is—and isn't—transmitted.

For starters, here are the main ways that the virus does spread:

  • By having vaginal or anal sex with an HIV-infected person (the risk of spreading the virus through oral sex, however, is extremely low).
  • By sharing needles and syringes with an injection drug user who is infected with HIV.
  • From HIV-infected women to their babies before or during birth, or via breastfeeding.

Following are some of the other ways that some people think HIV spreads, along with the facts from CDC.

Blood transfusions. The risk of HIV infection through blood transfusions or blood products is extremely low. In fact, the U.S. blood supply is among the safest in the world for these reasons:

  • Strict donor selection practices are in place.
  • All donated blood in the United States is tested for HIV (and has been since 1985).
  • Processing methods for blood products have continued to improve, reducing the number of infections that result from these products.

Body fluids. Contact with saliva, tears or sweat has never been shown to result in the transmission of HIV.

Among people who are infected, the following body fluids have been shown to contain high levels of the virus:

  • Blood.
  • Semen.
  • Vaginal fluid.
  • Breast milk.
  • Other body fluids that contain blood.

Kissing. No one has become infected with HIV through casual, closed-mouth kisses.

Prolonged open-mouth, or French, kissing, however, could potentially transmit HIV if the infected person's mouth is bleeding. Although the risk of HIV transmission in this way is very low, CDC recommends against open-mouth kissing with a partner you know is infected with HIV if both of you have open-mouth sores or bleeding gums.

The environment. HIV is not an airborne or food-borne virus, and it does not live long outside the body. You can't become infected from a toilet seat, a drinking fountain, a doorknob, dishes, drinking glasses, food or pets. In fact, no one has been identified as becoming infected with HIV from contact with an environmental surface.

The air. CDC reports that there is no truth to rumors that claim a mutated version of HIV can be transmitted through the air. Many studies have investigated how HIV spreads, and the air is not among the conduits.

Insects. HIV can't be transmitted by mosquitoes or any other insects.

Tattooing and body piercing. CDC knows of no cases of HIV transmission via tattooing or body piercing (although the hepatitis B virus has been spread through some of these practices). However, HIV could be transmitted if contaminated instruments are not sterilized or disinfected between clients or if the ink is shared.

reviewed 10/21/2019

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