HIV Hurts the Immune System

Many people (not just kids, but adults, too) don't really understand how HIV and AIDS are related, even though they hear these two words used together all the time.
HIV stands for human immunodeficiency (say: ih-myoo-nuh-dih-fih-shun-see) virus. AIDS stands for acquired immunodeficiency syndrome. HIV is actually the virus that causes the disease AIDS.
HIV Hurts the Immune System People who are HIV positive have been tested and found to have signs of the human immunodeficiency virus in their blood. HIV destroys part of the immune (say: ih-myoon) system. Specifically, it affects a type of white blood cell called the T lymphocyte (say: lim-fuh-site), or T cell. T cells are one type of "fighter" cell in the blood that help the body fight off all kinds of germs and diseases.
After HIV enters the body, it piggybacks onto a T cell and works its way inside of that cell. Once inside, the virus completely takes over the T cell and uses it as a virus-making factory to make a lot of copies of itself. The newly made viruses then leave the T cell and go on to infect and destroy other healthy T cells as they continue to multiply inside the body. After the virus invades the T cells, they can no longer properly fight infections.
Someone who is infected with the virus is called HIV positive. But it may take years for the virus to damage enough T cells for that person to get sick and develop AIDS. And thanks to new medications, someone infected with HIV can stay relatively healthy and symptom-free for many years. But these medications are very expensive and not available to everyone in the world.
Although the HIV-positive person may feel fine, the HIV virus is silently reproducing itself and destroying T cells. And during this time, the person is still contagious (say: kon-tay-jus), which means he or she is able to give the disease to others.
When the person's immune system has weakened and more of the blood's T cells have been destroyed by the virus, the person can no longer fight off infections. This is when he or she gets very sick. A doctor diagnoses a person with AIDS when the person has a very low number of T cells and shows signs of a serious infection.
How Many People Have HIV and AIDS?Since the discovery of the HIV virus more than 20 years ago, millions of people throughout the world have been infected with HIV. Most are adults, but there are kids and teens who have HIV, too. In the world today, AIDS remains an epidemic (say: eh-puh-deh-mik), which means that it affects a large number of people and continues to spread rapidly.
Right now, about 40 million people in the world are living with HIV infection or AIDS. This estimate includes 37 million adults and 2.5 million children. In the United States alone, more than 1 million people are living with HIV.