How is HIV passed from one person to another?

HIV transmission can occur when fluids (shown to contain high concentrations of HIV) from an infected person enter the body of an uninfected person.

  • Blood
  • Semen
  • Pre-seminal fluid
  • Vaginal fluid
  • Breast milk
  • Other body fluids containing blood

HIV has been found in saliva and tears of some persons living with HIV, but in very low quantities.

Finding a small amount of HIV in a body fluid does not necessarily mean that HIV can be transmitted by that body fluid. HIV has not been recovered from the sweat of HIV-infected persons. Contact with saliva, tears, or sweat has never been shown to result in transmission of HIV.

HIV can enter the body through:

  • A vein (during injection drug use)
  • The lining of the anus or rectum
  • The lining of the vagina and/or cervix
  • The opening of the penis
  • The mouth
  • Other mucous membranes (i.e., eyes, nose)
  • Cuts and sores
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Intact, healthy skin is an excellent barrier against HIV and other viruses and bacteria.

The most common ways HIV is transmitted from one person to another are:

  • Exchanging blood, semen, and vaginal secretions through vaginal, oral or anal intercourse with someone who has HIV
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  • Sharing needles or syringes used for injecting drugs, medicines, tattooing or body piercing with someone who has HIV
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  • A pregnant woman who is HIV positive can pass HIV to her unborn baby through the umbilical cord during birth, contact with vaginal fluids and blood during birth or breast milk after the child is born