How is HIV transmitted?

HIV can be transmitted when blood, semen (including pre-seminal fluid or pre-cum), vaginal fluids, or breast milk from an infected person enters the body of an uninfected person. HIV must get into the bloodstream or body in order to cause infection. Transmission most often occurs during unprotected sex or during injection drug use when equipment is shared. An infected woman who becomes pregnant can transmit HIV to her baby during pregnancy or during birth, but this risk is significantly less if the woman takes antiretroviral drugs. She can also pass HIV to her newborn if she breastfeeds. Anyone infected with HIV can transmit it, whether or not they appear sick, have an AIDS diagnosis, or are successfully treating their infection with antiretroviral drugs. HIV is spread in the following ways: Unprotected anal, vaginal or oral sex HIV can enter the body during sex through the anus, vagina, opening at the end of the penis or mouth and through cuts, sores and abrasions on the skin. Unprotected anal and vaginal sex have the highest risk of infection. There are a growing number of reported cases where HIV has been transmitted during oral sex (mouth to genital contact), but oral sex is much less risky than anal or vaginal sex.

Anyone having unprotected sex (inserting or receiving partner) with an infected person is at risk of getting HIV. The person most at risk is the receiving partner. Heterosexually, women are at higher risk than men.

Blood exposure. Sharing needles or drug injection equipment can transmit HIV (and other viruses like hepatitis). After use, small amounts of blood can remain in the used needles, syringes, cookers, cottons, and water. This remaining blood can enter the body of the next user when any of these items are shared. If this blood is HIV infected, transmission can easily occur.

There is a very small but real risk of health care workers getting HIV from infected patients as a result of needle stick accidents or when blood gets into a worker`s open cut or a mucous membrane in their eyes, mouth or nose. The risk for health care workers is greatly reduced when universal precautions are carefully followed, such as safe disposal of sharps, wearing latex gloves, etc. Universal precautions also protect patients.

Very rarely in this country is HIV transmitted when receiving a blood transfusion, blood clotting factors, an organ or tissue transplant (the risk of acquiring HIV from a blood transfusion is approximately 1 in a million). Before 1985, there were no tests to screen blood and organ donations for HIV. Now, blood, organ and tissue banks extensively test all specimens for HIV and other blood-borne germs.

Mother to child If a woman is infected with HIV, she can give it to her baby during pregnancy, during birth, or by breastfeeding. Early in the epidemic, 25% (1 out of 4) of babies born to HIV-infected women in this country became infected with HIV. Now, in developed countries where early detection of HIV is possible, treatment with the latest antiretroviral medications can reduce this rate to about 1% (1 out of 100). All pregnant women should see a doctor, be tested for HIV, and if infected, obtain the best treatment.