What's the Difference Between AIDS and HIV?
drkoop.com Health News
In the strict sense, AIDS is not a separate disease, but the final, fatal stage of HIV infection. That is why it is called a syndrome -- acquired immunodeficiency syndrome.
The many new medications now available can delay the appearance of AIDS for years. As a result, there have been fewer AIDS deaths, at least where the new treatments are available and reports of AIDS deaths are fairly reliable -- principally in the United States, Canada and western Europe. At the same time, the number of new HIV infections does not appear to be going down.
Deaths from AIDS have declined from about 49,000 in 1995 to about 17,000 in 1999. There are some 40,000 new HIV infections a year in the United States. The number has to be qualified, because in some states where HIV infection rates and AIDS deaths are known to be high -- notably New York and California -- there is no requirement that all HIV cases be reported.
From the moment of infection, a deadly battle begins in a victim's body. The virus attacks the immune system and destroys infection-fighting CD-4 cells. Each day, billions of new CD-4 cells are produced, and the virus destroys them. This can go on for years, but sooner or later the balance of power between the immune system and the virus begins to change.
When that happens, the immune system loses its ability to fight off other infections, many of which a healthy immune system could repel. Many patients do not know they are infected with HIV until that begins to happen. Doctors often diagnose AIDS by the appearance of what are called AIDS-defining illnesses. They include Pneumocystis carinii pneumonia, known as PCP; Kaposi's sarcoma, a rare form of cancer; and wasting syndrome, a serious weight loss.
There are also laboratory tests for AIDS. Tests can determine the viral load, the level of the virus in a patient's body. A very low level of CD-4 cells is diagnostic, and so is the presence of HIV antibodies.
Tuberculosis, once thought to be virtually eliminated in most countries, is a problem again because HIV has ravaged the immune systems of so many people. Other sexually transmitted diseases are common in places where the HIV rate is high. Many other "opportunistic infections" take advantage of the body's weakness to attack the liver, the lungs and even the brain. A patient may experience memory loss, become unable to concentrate and perform complex tasks, or have difficulty standing and walking.