The human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS). Many people think AIDS is a disease that affects only homosexual (gay) men and intravenous (IV) drug users. This is not true. The rate of HIV infection is increasing most rapidly among heterosexual women. HIV infection is the fifth leading cause of death among women 19–39 years of age.

HIV infection is not a disease that only "other people" get. Every woman must know how to protect herself, her partner, and any children she may choose to have.

How Infection Occurs

The HIV virus enters the bloodstream by way of body fluids—in most cases, blood or semen. Once in the blood, the virus invades and kills cells of the immune system. These cells are white blood cells called CD4 cells. When these cells are destroyed, the body is less able to fight disease. The number of these white blood cells often decreases in patients with advanced HIV infection.

How Infection Is Spread

HIV infection is spread through contact with some types of body fluids of an infected person. This can happen during sex or by sharing needles used to inject drugs. An infected woman who is pregnant can pass the virus to her baby. Women with HIV who breastfeed also can pass the virus to their babies. Once someone is infected, he or she always will carry the virus and can pass it to others.

People may become infected with HIV if they are exposed to infected blood or blood transfusions during a medical procedure. This was not known until 1985, so persons who received blood transfusions before then could have been infected this way. All donor blood in the United States is now screened for diseases such as HIV, so the risk of getting infected this way is very low.

People also may become infected if they are exposed to infected blood by accident. For instance, some health care workers have become infected from contact with their patients' infected blood.

HIV cannot be spread by casual contact with people and objects. The virus cannot get through skin that is not broken.

Learn more about HIV.