Scientists have identified three ways that HIV infections spread: sexual intercourse with an infected person, contact with contaminated blood, and transmission from an infected mother to her child before or during birth or through breastfeeding.
HIV infection is spread in three ways:
Sexual intercourse
Direct contact with infected blood
From an infected mother to her unborn child
Sexual Intercourse
HIV is spread most commonly by sexual contact with an infected partner. The virus can enter the body through the lining of the vagina, penis, rectum, or mouth during sexual relations.
Sexual activities that can result in HIV infection include:
Sexual intercourse
Anal sex (heterosexual or homosexual)
Oral sex (heterosexual or homosexual)
Direct Contact With Infected Blood
HIV can be spread through direct contact with infected blood:
Through injected drugs. HIV frequently is spread among users of illegal drugs that are injected. This happens when needles or syringes contaminated with minute quantities of blood of someone infected with the virus are shared.
In a health-care setting. Transmission from patient to health-care worker or vice-versa - via accidental sticks with contaminated needles or other medical instruments - can occur, but this is rare.
Through a blood transfusion. Prior to the screening of blood for evidence of HIV infection and before the introduction in 1985 of heat-treating techniques to destroy HIV in blood products, HIV was transmitted through transfusions of contaminated blood or blood components. Today, because of blood screening and heat treatment, the risk of acquiring HIV from such transfusions is extremely small.
From An Infected Mother To Her Unborn Child
Women can transmit HIV to their fetuses during pregnancy or birth. Approximately one-quarter to one-third of all untreated pregnant women infected with HIV will pass the infection to their babies.
A pregnant woman can greatly reduce the risk of infecting her baby if she takes the anti-HIV drug AZT (also called zidovudine) during her pregnancy. Because the risk of transmission increases with longer delivery times, the risk can be further reduced by delivering the baby by cesarean section, a surgical procedure in which the baby is delivered through an incision in the mother's abdominal wall and uterus. Combining AZT treatment with cesarean delivery can reduce the infection rate to between 1% and 2%.
HIV also can be spread to babies through the breast milk of mothers infected with the virus.
Women who live in countries where safe alternatives to breast-feeding are readily available and affordable can eliminate the risk of transmitting the virus through breast milk by bottle-feeding their babies.
In developing countries, however, where such safe alternatives are not readily available or economically feasible, breast-feeding may offer benefits that outweigh the risk of HIV transmission.
How Is HIV Infection Not Spread?
Research indicates that HIV is NOT transmitted by casual contact such as:
Touching or hugging
Sharing household items such as utensils, towels, and bedding
Contact with sweat or tears
Sharing facilities such as swimming pools, saunas, hot tubs, or toilets with HIV-infected people
Coughs or sneezes
In short, studies indicate that HIV transmission requires intimate contact with infected blood or body fluids (vaginal secretions, semen, pre-ejaculation fluid, and breast milk). Activities that don't involve the possibility of such contact are regarded as posing no risk of infection.
