18 Ocak 2008 Cuma

HIV, AIDS What Is HIV?

HIV, AIDS
What Is HIV?
"HIV" stands for Human Immunodeficiency Virus.
Many people also refer to HIV as the "AIDS virus."

How Is the Virus Transmitted?
HIV lives in blood and other body fluids that contain blood or white blood cells. People have gotten HIV through:
· unprotected sexual intercourse with an HIV-infected person. This includes vaginal or anal intercourse, and oral sex on a man or woman without a condom or other barrier. Intercourse while a woman is having her period, or during outbreaks of genital sores or lesions (caused by herpes and other sexually transmitted diseases) can increase the risk of HIV transmission.
· sharing drug injection equipment (needles and/or works); or being accidentally stuck by needles or sharp objects contaminated with infected blood.
· infected blood used in transfusions, and infected blood products used in the treatment of certain diseases and disorders (like hemophilia), before March, 1985. (Since 1985, federally mandated screening of the blood supply has reduced the risk of transmission through this route to 1 in 255,000.)
· pregnancy, childbirth, and/or breastfeeding, where the virus is passed from mother to child.
· transplanted organs from infected donors. (Routine screening of organ donors also began in 1985.)
HIV and AIDS are not transmitted through casual contact (that is, where no blood or body fluids are involved). HIV is what gets passed from person to person. People don't "catch AIDS"; they "become infected with HIV."

What Does an "HIV-Positive" Test Result Mean?
A positive test result means your body has been infected by the human immunodeficiency virus-and that you are capable of transmitting it to others. The test did not look for the actual virus itself, but found evidence of it in your blood. There's no way to tell from this result who gave you the virus, how long you've had it, or when it will begin to affect your health. You may see or hear the results called "HIV-positive," "HIV+," "HIV-antibody positive," or "seropositive for HIV." These terms all mean the same thing. People who have been infected with the human immunodeficiency virus are said to have "HIV disease." While the virus itself is not a disease, it progressively damages the body's immune system. This puts you at risk for developing illnesses you wouldn't otherwise get.
At this time, doctors don't know of any way to rid the body of HIV. There is no cure. Once you've been infected, you have it for life.

How Does HIV Harm the Body?
Viruses tend to be specialists. They zero in on a few particular types of cells in the body and move in. The human immunodeficiency virus is best known for targeting the T cells of the immune system. However, it can also attack cells of the brain, nervous system, digestive system, lymphatic system, and other parts of the body.
The immune system is made up of specialized cells in the bloodstream that fight off invading germs to keep the body healthy. The "T" cells (also referred to as "T4," "helper-T," or "CD4" cells) are the brains of the operation. These white blood cells identify invaders and give orders to soldier-type cells, which then battle various bacteria, viruses, cancers, fungi, and parasites that can make a person sick.
Like all viruses, the HIV is only interested in one thing: reproducing itself. Once it has attacked and moved into a T cell, it converts that cell into a miniature virus factory. Eventually there are so many new viruses in the cell that the T cell explodes, scattering the HIV back into the bloodstream. The virus then moves on to fresh T cells and repeats the process. Over time, the HIV can destroy virtually all of an infected person's T cells in this manner.

Then What Happens?
With fewer and fewer "leaders" to rely on for warnings, the "soldier" cells become powerless. They can no longer recognize and fight off common organisms that would not present a problem to a healthy immune system. These organisms may be lying dormant in the body already, or may enter from outside. The immune system's weakness gives them the opportunity to wake up, multiply, and cause illness. Thus, we call these illnesses "opportunistic infections." People with fully functioning immune systems are almost never troubled by these particular infections-but those with damaged immune systems are highly vulnerable to them.

So What's the Connection Between HIV and AIDS?
When a person with an HIV-weakened immune system comes down with one or more of these rare opportunistic infections, or has a T cell count below 200 or 14%, that person may be diagnosed by a doctor as having AIDS. "AIDS" stands for "Acquired Immune Deficiency Syndrome." The "syndrome" part means that AIDS is not a single disease but a collection of diseases. The Centers for Disease Control (CDC) has put together a list of 26 "AIDS-defining illnesses" in adults. Diagnosis of AIDS in children involves a list of slightly different ailments.
AIDS can be thought of as the most severe form of HIV disease. All but a handful of medical experts now believe that HIV is the primary agent that leads to the development of AIDS.

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