Most people know that the virus is commonly spread through sexual contact and intravenous drug use. But what other behaviors are — and are not — risk factors?
HIV: How It’s Transmitted
HIV is spread through certain body fluids, such as blood, semen (including pre-seminal fluid), rectal fluids, vaginal fluids, and breast milk, according to the U.S. Department of Health and Human Services AIDS.gov website. The virus can be transmitted when these fluids in an infected person come into contact with mucous membranes in the rectum, vagina, penis, or mouth of another person. While HIV can be spread during anal or vaginal sex, anal sex is riskier because there is more trauma and irritation to the mucous membranes, says Beverly Sha, MD, professor of medicine in the division of infectious diseases at Rush University Medical Center in Chicago. Although the risk is low, HIV can also be spread through oral sex. HIV transmission can happen during ejaculation into the mouth, or if there are mouth ulcers, bleeding gums, genital sores, or other sexually transmitted diseases present, according to the Centers for Disease Control and Prevention. Using condoms during sex lowers the risk of HIV transmission. “When they are used properly, it’s clear they offer significant protection,” Dr. Sha says. However, condoms can fail when they break, if they’re too old, or if they are not used correctly. The virus can also spread if infected fluids come into contact with damaged tissue, such as a cut in the skin, or if infected blood is transferred from a needle or syringe. Doing injection drugs with someone who is infected and sharing equipment is high risk. HIV can be found in a used needle for as long as 42 days. Pregnancy is another risk factor to be aware of. While HIV can be spread from an infected mother to her baby during pregnancy, treatment lowers the chances to less than 1 percent, according to AVERT, a nonprofit dedicated to HIV and AIDS education.
HIV: How It’s Not Transmitted
The following are nine ways the virus is not spread: Kissing and touching. Social kissing and hugging pose no risk of transmission, Sha says. Also, being sexual with someone without exchanging infected body fluids does not spread the virus. The only time deep kissing is a risk is when the person infected with HIV has open sores or oral bleeding, Sha notes. Sharing a living space. Any casual contact with someone who has HIV, including sharing a bathroom, is safe. However, Sha tells patients not to share razor blades or toothbrushes. If someone who is infected nicks himself while shaving or has bleeding gums, it could increase risk of transmission. Sharing food or utensils. The virus cannot survive on surfaces, so sharing utensils and other household items will not spread HIV. You can even share a meal with someone who is infected without worry. Transmission has been associated with mothers pre-chewing food for their babies, when infected blood from the mouth mixes with the food. Known as pre-mastication, it is a common practice in Africa, but not typically done in the United States, Sha says. Saliva, sweat, or tears. An infected person’s saliva, sweat, and tears do not put you at risk. Helping an injured person with HIV. Wearing gloves while doing so is ideal; but even if the person’s blood comes into contact with your intact skin, you should not worry. “We don’t consider blood exposure to intact skin to be a risk,” Sha says. There needs to be a cut or abrasion to allow the virus to get past the skin layer. Water fountains. Sipping from a water fountain after someone who has HIV used it is considered casual contact and will not lead to transmission. Mosquitoes and other insects. The virus is not viable in insects or ticks, Sha says. Toilet seats. HIV cannot survive on surfaces, so this is not a concern. Modern blood transfusions. Donated blood is screened and disposed of if it tests positive for HIV. Advanced technology has made screening increasingly sensitive at identifying the virus, Sha says.
