HIV Transmission

Perinatal Transmission

Women living with HIV can pass the virus to their babies while pregnant, during birth, or by breastfeeding. This is called perinatal or vertical transmission, and is also known as mother-to-child transmission. The good news is that medical care and HIV drugs given during pregnancy can almost eliminate the risk of a baby getting HIV from its mother.

In resource-rich countries like the U.S., it is recommended that mothers living with HIV not breastfeed their babies. In other countries, where formula is unavailable or clean water sources are unreliable, it is recommended that mothers breastfeed their babies exclusively (no mixed feeding, such as some breast milk and some gripe or sugar water). It is also important not to feed your baby food that has been chewed by someone who is living with HIV (pre-masticated). This can transmit HIV to your child. For more information, see our fact sheet on Pregnancy and HIV.

Other Types of Transmission

In the past, HIV was spread by transfusion with blood products, such as whole blood or the "factor" used by hemophiliacs. Many people acquired HIV this way. The blood supply is now much more strictly tested and controlled in most countries. The odds of acquiring HIV from receiving blood or blood factor in countries like the U.S., the UK, and Canada are vanishingly low. In the U.S., for example, a person is more likely to be killed by a lightning strike than to acquire HIV from a blood transfusion. Only about 1 in 2 million donations might carry HIV. However, there are still several countries that do not screen all blood donations for HIV.

It is also possible to get HIV from skin grafts or transplanted organs taken from people living with HIV. Again, the risk is considered very low, as these 'body products' are required to be strictly tested in the same way as blood products. Semen donations collected by sperm banks for artificial insemination are also considered 'bodily products' and strictly tested in high-resource countries. Private semen samples that are not processed by sperm banks or similar organizations are not subject to the same testing. It is important for anyone receiving a private donor's sperm for artificial insemination to have the donor tested for HIV.

Some people, mostly health care workers, are infected through needle sticks with infected blood, or through other medical accidents. This is a very small percentage of overall infections. According to the CDC, only three in every 1,000 exposures to HIV-infected blood at work, if left untreated, will result in HIV infection. When exposed to fluid or body products that may be infected while on the job, health care workers should be offered occupational post-exposure prophylaxis (oPEP) immediately.

If you are getting breast milk from a milk bank, it is important to ask if the bank tests the milk for HIV. Also, if your baby is getting breast milk from a wet nurse, it is important to make sure that she tests negative for HIV before giving her milk to your baby.

Rare Types of Transmission

There are a few isolated cases of people becoming HIV-positive from using a razor that had just been used by a person living with HIV, or from using a toothbrush immediately after the toothbrush was used by someone living with HIV, or in other unexpected ways. One case of transmission occurred when two people, both of whom had bleeding gums and/or open sores in their mouths, engaged in deep or "French" kissing. In this situation, they were exposed not only to each other's saliva (which does not carry HIV), but also to each other's blood (which can transmit HIV). To be safe, always avoid direct contact with blood and sexual fluids.

Avoiding Transmission

HIV cannot be transmitted except when certain body fluids are exchanged. You can greatly reduce the risk of transmission by:

• Knowing your HIV status so you can take steps to avoid spreading HIV if you are living with HIV; for more information, see our fact sheet on HIV Testing
• Practicing safer sex including taking PrEP
• Having sex without condoms or other barriers only if you and your partner are both HIV-negative and in a monogamous relationship
• Abstaining from sex
• Not injecting drugs
• Using new or clean needles and other equipment for any injections
• Staying on your HIV drug regimen if you are living with HIV. This will keep your viral load as low as possible. Keeping your viral load low will reduce the risk of your passing HIV to others (sexual partners, mother-to-child)

You do not need to be afraid of getting or passing HIV by casual contact. Remember, HIV is not transmitted by:

• Hugs
• Dancing
• Sharing food or drinks
• Using a toilet, shower, bath, or bed
• Kissing (between people with no significant dental problems)
• Sharing exercise equipment
• Bug bites