WHAT DOES "AIDS" MEAN?
AIDS stands for Acquired Immune Deficiency Syndrome:
AIDS is caused by a virus called the Human Immunodeficiency Virus (HIV). If you get infected with HIV, your body will try to fight the infection. It will make "antibodies," special immune molecules the body makes to fight HIV.
Tests for HIV look for these antibodies in your blood or mouth lining. If you have them in your blood, it means that you have HIV infection. People who have the HIV antibodies are called "HIV-Positive." Fact Sheet 102 has more information on HIV testing.
Being HIV-positive, or having HIV disease, is not the same as having AIDS. Many people are HIV-positive but don't get sick for many years. As HIV disease continues, it slowly wears down the immune system. Viruses, parasites, fungi and bacteria that usually don't cause any problems can make you very sick if your immune system is damaged. These are called "opportunistic infections." (Fact Sheet 500).
You don't actually "get" AIDS. You might get infected with HIV, and later you might develop AIDS. You can get infected with HIV from anyone who's infected, even if they don't look sick and even if they haven't tested HIV-positive yet. The blood, vaginal fluid, semen, and breast milk of people infected with HIV has enough of the virus in it to infect other people. Most people get the HIV virus by:
Getting a transfusion of infected blood used to be a way people got AIDS, but now the blood supply is screened very carefully and the risk is extremely low.
There are no documented cases of HIV being transmitted by tears or saliva.
For more information, see the following Fact Sheets:
The US Centers for Disease Control and Prevention (CDC) estimates that about 1.3 million people are living with HIV infection or AIDS; about 15% of them do not know they have it. About 73 percent of the 56,000 new infections each year are in men and about 27 percent are in women. About half of the new infections are in Blacks, even though they make up only 12 percent of the US population. In the mid-1990s, AIDS was a leading cause of death. However, newer treatments have cut the AIDS death rate significantly. For more information, see the US Government fact sheet at http://www.cdc.gov/hiv/topics/surveillance/index.htm.
You might not know if you are infected by HIV. Within a few weeks of being infected, some people get fever, headache, sore muscles and joints, stomach ache, swollen lymph glands, or a skin rash for one or two weeks. Most people think it's the flu. Some people have no symptoms. Fact Sheet 103 has more information on the early stage of HIV infection.
The virus will multiply in your body for a few weeks or even months before your immune system responds. During this time, you won't test positive for HIV, but you can infect other people.
When your immune system responds, it starts to make antibodies. When this happens, you will test positive for HIV.
After the first flu-like symptoms, some people with HIV stay healthy for ten years or longer. But during this time, HIV is damaging your immune system.
One way to measure the damage to your immune system is to count your CD4 cells you have. These cells, also called "T-helper" cells, are an important part of the immune system. Healthy people have between 500 and 1,500 CD4 cells in a milliliter of blood. Fact Sheet 124 has has more information on CD4 cells.
Without treatment, your CD4 cell count will most likely go down. You might start having signs of HIV disease like fevers, night sweats, diarrhea, or swollen lymph nodes. If you have HIV disease, these problems will last more than a few days, and probably continue for several weeks.
With treatment, CD4 counts can recover, or remain normal. Life expectancy for people who know their status and take antiretroviral treatment (ART) is nearly normal for people who adhere to their medications.
HIV disease becomes AIDS when your immune system is seriously damaged. If you have less than 200 CD4 cells or if your CD4 percentage is less than 14%, you have AIDS. See Fact Sheet 124 for more information on CD4 cells. If you get an opportunistic infection, you have AIDS. There is an "official" list of these opportunistic infections put out by the Centers for Disease Control (CDC). The most common ones are:
AIDS-related symptoms also includes serious weight loss, brain tumors, and other health problems. Without treatment, these opportunistic infections can kill you. The official (technical) CDC definition of AIDS is available at http://www.thebody.com/content/art14002.html
AIDS is different in every infected person. A few people may die a few months after getting infected, but most live fairly normal lives for many years, even after they "officially" have AIDS. A few HIV-positive people stay healthy for many years even without taking antiretroviral medications (ART).
Though there are two cases of people who have been cured, there is currently no safe cure for HIV (see fact sheet 485.) There is no way to "clear" HIV from the body. Antiretroviral therapy (ART, see fact sheet 403) can prevent or reverse the damage to your immune system. Most people stay healthy if they stay adherent to ART.
Other drugs can prevent or treat opportunistic infections (OIs). ART has also reduced the rate of most OIs. In most cases, these drugs work very well. The newer, stronger ARVs have helped reduce the rates of most OIs.
More detailed information on AIDS can be found at MedLine Plus at http://www.nlm.nih.gov/medlineplus/aids.html