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How is HIV
passed from one person to another?
HIV transmission can occur
when blood, semen (including pre-seminal fluid, or "pre-cum"),
vaginal fluid, or breast milk from an infected person enters
the body of an uninfected person.
HIV can enter the body through
a vein (e.g., injection drug use), the anus or rectum, the vagina,
the penis, the mouth, other mucous membranes (e.g., eyes or inside
of the nose), or cuts and sores. Intact, healthy skin is an excellent
barrier against HIV and other viruses and bacteria.
These are the most common
ways that HIV is transmitted from one person to another:
- by having sexual intercourse
(anal, vaginal, or oral sex) with an HIV-infected person
- by sharing needles or injection
equipment with an injection drug user who is infected with HIV
- from HIV-infected women
to babies before or during birth, or through breast-feeding after
birth
HIV also can be transmitted
through transfusions of infected blood or blood clotting factors.
However, since 1985, all donated blood in the United States has
been tested for HIV. Therefore, the risk of infection through
transfusion of blood or blood products is extremely low. The
U.S. blood supply is considered to be among the safest in the
world. (For more information, see "How safe is the blood supply in the
United States?")
Some health-care workers
have become infected after being stuck with needles containing
HIV-infected blood or, less frequently, after infected blood
contact with the worker's open cut or through splashes into the
worker's eyes or inside their nose. There has been only one instance
of patients being infected by an HIV-infected health care worker.
This involved HIV transmission from an infected dentist to six
patients. (For more information, see "Are health care workers at risk of
getting HIV on the job?"
and "Are patients in a dentist's or doctor's office at risk
of getting HIV?") |
