2. How Does HIV Spread?

Which body fluids contain HIV?

HIV lives and reproduces in blood and other body fluids.

We know that the following fluids can contain high levels of HIV:

• Blood
• Semen
• Pre-seminal fluid
• Breast milk
• Vaginal fluids
• Rectal (anal) mucous

Other body fluids and waste products - like faeces, nasal fluid, saliva, sweat, tears, urine, or vomit - don’t contain enough HIV to infect you, unless they have blood mixed in them and you have significant and direct contact with them.

For more information, see CDC’s HIV Transmission: Which Body Fluids Transmit HIV?

Healthcare workers may be exposed to some other body fluids with high concentrations of HIV, including:

• Amniotic fluid
• Cerebrospinal fluid
• Synovial fluid

How is HIV transmitted through body fluids?

HIV is transmitted through body fluids in very specific ways:

• During sexual contact:  When you have anal, oral, or vaginal sex with a partner, you will usually have contact with your partner’s body fluids. If your partner has HIV, those body fluids can deliver the virus into your bloodstream through microscopic breaks or rips in the delicate linings of your vagina, vulva, penis, rectum, or mouth. Rips in these areas are very common and mostly unnoticeable. HIV can also enter through open sores, like those caused by herpes or syphilis, if infected body fluids get in them.
• Sexually transmitted diseases:  You need to know that it’s much easier to get HIV (or to give it to someone else) if you have a sexually transmitted disease (STD). For more information, see CDC's The Role of STD Detection and Treatment in HIV Prevention.
• During pregnancy, childbirth, or breastfeeding:  Babies have constant contact with their mother’s body fluids-including amniotic fluid and blood-throughout pregnancy and childbirth. After birth, infants can get HIV from drinking infected breast milk.
• As a result of injection drug use:  Injecting drugs puts you in contact with blood-your own and others, if you share needles and “works”. Needles or drugs that are contaminated with HIV-infected blood can deliver the virus directly into your body.
• As a result of occupational exposure:  Healthcare workers have the greatest risk for this type of HIV transmission. If you work in a healthcare setting, you can come into contact with infected blood or other fluids through needle sticks or cuts. A few healthcare workers have been infected when body fluids splashed into their eyes, mouth, or into an open sore or cut.
• As a result of a blood transfusion with infected blood or an organ transplant from an infected donor:  Screening requirements make both of these forms less likely to occur, but the possibility still exists. 

Click here to watch a video about sexually transmitted diseases

How do you get Aids?

AIDS is the late stage of HIV infection when a person’s immune system is severely damaged and has difficulty fighting diseases and certain cancers. Before the development of certain medications, people with HIV could progress to AIDS in just a few years. Currently, people can live much longer - even decades - with HIV before they develop AIDS. This is because of “highly active” combinations of medications that were introduced in the mid-1990s.