HIV and AIDS are primarily transmitted in the following ways:

Sexual Activity--Sexual activity is the most common form of HIV transmission. HIV can be transmitted through any kind of sexual activity (vaginal, anal, and oral) and can occur when bodily fluids of an HIV-positive partner enter into the other partner, including through small, even unidentifiable, cuts or scratches. Women, and especially girls, are twice as vulnerable as men to contracting HIV through sexual activity due to their biological and physiological characteristics. This vulnerability rises substantially in cases of coercive and/or violent sexual intercourse.

Sexually Transmitted Infections--The risk of transmission is further increased if either partner has a sexually transmitted infection (STI). An STI is any disease that is passed from one person to another through sexual contact, such as chlamydia, genital herpes, genital warts, gonorrhea, and syphilis. HIV is also an STI.

A person with an STI is 10 times more likely to transmit or acquire HIV than a person without an STI because (1) many STIs cause open sores or breaks in the skin, providing an avenue for HIV to enter the body, and (2) the bodily fluids of individuals with STIs have an increased concentration of helper T cells, which serve as targets for HIV and may increase the risk of infection.

Symptoms of STIs include open sores or breaks in the skin around the genitals; white, yellow, or green vaginal discharge; burning sensation when passing urine; itchiness in the genital area; pain in the lower stomach or back; pain in the testicles; and pain during sexual activity.

Some STIs, however, have no symptoms. (Thus, it is important to visit a health clinic for proper diagnosis and treatment if you think there is a possibility that you have been exposed.) Most STIs are curable. Left untreated, STIs—in addition to facilitating the transmission of HIV—can lead to serious complications, including infertility and cervical cancer.

Blood Transfusions--An individual can become infected if she is given HIV-infected blood during a blood transfusion. Most countries now test donated blood for HIV, lowering the risk. However, in situations where such screening is not done the risk is much higher.

Sharing Needles or Using Syringes and Razor Blades--Needles, syringes, razor blades, and other instruments that pierce the skin (for drug injection, tattooing, piercing, carving scars, circumcision, or shaving) can transmit the virus if they were first used by an infected person. One can even contract HIV in a health care setting if syringes, needles, and equipment are not properly sterilized.

Mother-to-Child Transmission--An HIV-infected woman can pass the virus to her baby during pregnancy through the placenta, and during childbirth through exposure to the mother’s blood. Without treatment, approximately 15 to 30 percent of babies born to HIV-positive mothers are infected with the virus. HIV can also be transmitted to a breastfeeding baby through the mother’s milk. Breastfeeding by an HIV-positive mother increases the risk of transmission to her baby by 10 to 20 percent. Antiretroviral preven-tative treatment is an effective method of preventing mother-to-child transmission of HIV. When combined with the use of safer infant-feeding methods, it can halve the risk of infant infection.

False Transmitters:

HIV is not acquired through the following:

Living in the same place with people who have HIV/AIDS

Kissing (unless there are open sores or exposure to blood within the mouth)

Touch (hugging, hand-shaking, or sports contact)

Bites from mosquitoes or other insects

Shared food, utensils, cups, or dishes

Shared swimming pools or bathing facilities

Sneezes or coughs

Hospital visits

Sweat, saliva, or tears*

Urine or feces*

Research indicates that HIV can be found in these substances, but in too low of a concentration for transmission