HIV can infect anyone whose blood comes into contact with an infected person's blood, breast milk, or sexual fluids. Some people engage in behaviors which place them at greater than normal risk. For example:
- Risky, unprotected sexual behaviors, like having sex without a condom and having multiple sex partners, can increase someone's chance of getting infected. These sexual risk behaviors are common among teens and young adults, who have very high rates of HIV infection compared to other Americans. Read more about young people and HIV. Additionally, men who have sex with men and individuals who have anal sex are at high risk of infection.
- Exposure to the virus as a fetus or infant before or during birth or through breastfeeding from a mother who is HIV positive.
- People with other sexually transmitted infections, such as chlamydia, gonorrhea, syphilis, bacterial vaginosis, and herpes, increase their risk of getting infected if they are exposed to the virus through sex or blood exposure.
- Using drugs can increase risk. Sharing needles or syringes to inject drugs or steroids can pass the virus. Drug use can also make people take risks they would not ordinarily take, like having risky, unprotected sex.
- People who received blood products in the United States between 1978 and 1985 before all blood was tested may have been exposed to the virus.
- Infants who are fed food that has been pre-chewed by an HIV-infected person may be at higher risk. HIV in blood in the caregiver's mouth can mix with the food while chewing; this is a rare occurrence and has been reported only in infants.
The Centers for Disease Control and Prevention has more information about HIV transmission.