- Have unprotected sex with an HIV-positive person.
- Share a needle with someone with HIV.
- Have sex with an HIV-positive person when you have a sexually transmitted infection (STI).
Unprotected sex. Risky sexual behavior is one of the most common ways HIV spreads from person to person. When you have sex, you exchange body fluids with your partner. You’re at a higher HIV risk if you have:
- A partner who is high-risk or already has HIV
- Many sex partners
- Sex with someone who has many sex partners
- An uncircumcised penis
The kind of sex you have makes a difference in your risk, too:
While there are only a few studies that have looked at it, it appears there’s little risk of getting HIV from oral sex. It’s even safer if you use a dental dam (latex or polyurethane sheets between the mouth and vagina/anus) or a male or female condom.
Needle sharing. This is the second-riskiest behavior when it comes to HIV, after anal sex. You expose yourself to infection from the blood or fluid left in the syringe. If the needle you’re sharing is for illegal drug use, you’re also putting yourself at risk by impairing your judgment. That makes you more likely to do other risky things, like having unprotected sex when you’re under the influence of drugs.
You should never use a needle that someone else has used first.
- Open sores or inflammation caused by STIs let the virus enter your body when you have sex with someone who is HIV-positive.
- The partner you get an STI from may be having risky sex, raising your chances of getting HIV.
- The behaviors that lead to an STI infection, such as sex with many partners, unprotected sex, or sex with partners you don’t know, are the same behaviors that increase your risk of HIV.
If you work in certain professions, your risk of coming into contact with body fluids from a person with HIV goes up. These include:
- Health care (doctors, nurses, technicians)
- Labs that handle blood or semen
Women can pass on HIV to their babies during pregnancy, delivery, or breastfeeding. These are the most common ways that children become HIV-positive. But chances of such mother-to-child transmissions can fall to as low as 1% if both the women and the infant are given HIV medicine throughout the pregnancy and the first several weeks of the newborn’s life.
You’re also at a higher risk if you live in a state that has a higher rate of HIV. The areas in the U.S. with the highest rates of HIV transmission are:
- Washington, DC (district)
- South Carolina
- Puerto Rico (territory)
It’s possible, but very unlikely, to get HIV from:
- Food pre-chewed by someone with HIV (in infants)
- A blood transfusion
- Organ or tissue transplant
- Artificial insemination
- Getting tattoos or body piercings. There are no documented cases in the U.S.
Before 1985, blood banks didn’t have a way to test for HIV. Today, blood banks screen donations. You can still get it from a transfusion from a person who contracted HIV right before they donated blood, but this is very rare.
You can’t get HIV from:
- Casual contact such as hugs, sharing a bed, or sharing utensils
- Swimming pools
- Toilet seats
- Insect bites