The Biology Project: Immunology

Immunology and HIV

Additional Information about HIV Transmission


Blood, semen (including pre-ejaculation fluid), vaginal secretions, and breast milk of infected individuals all contain high concentrations of HIV and can transmit HIV. These fluids must have direct access to your bloodstream in order to infect you. Activities where this can happen include vaginal intercourse, anal intercourse, performing oral sex, sharing unsterilized needles for IV drug use or tattoos, and through receiving a blood transfusion where the blood has not been screened for HIV. (The US blood supply has been screened for HIV since 1985.) Saliva, tears, sweat, and urine can contain HIV, but in such small concentrations that nobody has ever been infected through contact with these fluids. However, HIV transmission is possible through contact with any body fluid contaminated by blood. Health care workers should take care to prevent direct contact with any body fluids.

HIV is NOT transmitted through any form of casual contact. HIV is NOT transmitted through shaking hands, hugging, kissing, massaging, or living in the same house with someone who is HIV+. Additionally, HIV is not transmitted through insect bites. Recall that unbroken skin is an effective barrier against antigen. HIV can only gain access to the bloodstream through an open sore or abrasion. HIV doesn't survive more than a few minutes outside of a host.

For further information, View CDC's FAQ site under "HIV transmission and prevention"


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Monday, April 3, 2000
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