AIDS is one of the most serious, deadly diseases in human history. More than 20 years ago, doctors in the United States identified the first cases of AIDS in San Francisco and New York. Now there are an estimated 42 million people living with HIV or AIDS worldwide, and more than 3 million die every year from AIDS related illnesses.

AIDS is caused by the human immunodeficiency virus (HIV). HIV destroys a type of defense cell in the body called a CD4 helper lymphocyte (pronounced: lim-fuh-site). These lymphocytes are part of the body's immune system, the defense system that fights infectious diseases. But as HIV destroys these lymphocytes, people with the virus begin to get serious infections that they normally wouldn't - that is, they become immune deficient. The name for this condition is acquired immunodeficiency syndrome (AIDS).

As the medical community learns more about how HIV works, they've been able to develop drugs to inhibit it (meaning they interfere with its growth). These drugs have been successful in slowing the progress of the disease, and people with the disease now live much longer. But there is still no cure for HIV and AIDS.

Hundreds of U.S. teens become infected with HIV each year. HIV can be transmitted from an infected person to another person through blood, semen (also known as "cum," the fluid released from the penis when a male ejaculates), vaginal fluids, and breast milk.

The virus is spread through high-risk behaviors including:

• Unprotected oral, vaginal, or anal sexual intercourse. Unprotected means not using a condom.
• Sharing needles, such as needles used to inject drugs (including needles used for injecting steroids) and those used for tattooing.
• People who have another sexually transmitted disease, such as syphilis, genital herpes, chlamydia, gonorrhea, or bacterial vaginosis are at greater risk for getting HIV during sex with infected partners.

If a woman with HIV is pregnant, her newborn baby can catch the virus from her before birth, during the birthing process, or from breastfeeding. If doctors know an expectant mother has HIV, they can usually prevent the spread of the virus from mother to baby. All pregnant teens and women should be tested for HIV so they can begin treatment if necessary.

How does HIV affect the body?

A healthy body is equipped with CD4 helper lymphocyte cells (CD4 cells). These cells help the immune system function normally and fight off certain kinds of infections. They do this by acting as messengers to other types of immune system cells, telling them to become active and fight against an invading germ.

HIV attaches to these CD4 cells, infects them, and uses them as a place to multiply. In doing so, the virus destroys the ability of the infected cells to do their job in the immune system. The body then loses the ability to fight many infections.

Because their immune systems are weakened, people who have AIDS are unable to fight off many infections, particularly tuberculosis and other kinds of otherwise rare infections of the lung (such as Pneumocystis carinii pneumonia), the surface covering of the brain (meningitis), or the brain itself (encephalitis). People who have AIDS tend to keep getting sicker, especially if they are not taking antiviral medications properly.

AIDS can affect every body system. The immune defect caused by having too few CD4 cells also permits some cancers that are stimulated by viral illness to occur - some people with AIDS get forms of lymphoma and a rare tumor of blood vessels in the skin called Kaposi's sarcoma. Because AIDS is fatal, it's important that doctors detect HIV infection as early as possible so a person can take medication to delay the onset of AIDS.

How do people know they have HIV?

Once a person's blood lacks the number of CD4 cells required to fight infections, or the person has signs of specific illnesses or diseases that occur in people with HIV infection, doctors make a diagnosis of AIDS.

Severe symptoms of HIV infection and AIDS may not appear for 10 years. And for years leading up to that, a person may not have symptoms of AIDS. The amount of time it takes for symptoms of AIDS to appear varies from person to person. Some people may feel and look healthy for years while they are infected with HIV. It is still possible to infect others with HIV, even if the person with the virus has absolutely no symptoms. You cannot tell simply by looking at someone whether he or she is infected.

When a person's immune system is overwhelmed by AIDS, the symptoms can include:

• Extreme weakness or fatigue
• Rapid weight loss
• Frequent fevers that last for several weeks with no explanation
• Heavy sweating at night
• Swollen lymph glands
• Minor infections that cause skin rashes and mouth, genital, and anal sores
• White spots in the mouth or throat
• Chronic diarrhea
• A cough that won't go away
• Trouble remembering things
• Girls may also experience severe vaginal yeast infections that don't respond to usual treatment, as well as pelvic inflammatory disease (PID).

HIV and AIDS Preventation

How it can be prevented?

One of the reasons that HIV is so dangerous is that a person can have the virus for a long time without knowing it. That person can then spread the virus to others through high-risk behaviors. HIV transmission can be prevented by:

abstaining from sex (not having oral, vaginal, or anal sex)
always using latex condoms for all types of sexual intercourse
avoiding contact with the bodily fluids through which HIV is transmitted
never sharing needles

Diagnosis & Treatment of HIV AIDS

How it is diagnosed and treated?

If you think that you may have HIV or AIDS or if you have had a partner who may have HIV or AIDS, see your family doctor, adolescent doctor, or gynecologist. He or she will talk with you and perform tests. The doctor may do a blood test or a swab of the inside of your cheek. Depending on what type of test is done, results may take from a few hours to several days.

People can also get tested for HIV/AIDS at special AIDS clinics around the country. Clinics offer both anonymous (meaning the clinic doesn't know a person's name) and confidential (meaning they know who a person is but keep it private) testing. Most AIDS testing centers will ask you to follow up for counseling to get your results, whether the test is negative or positive.

If you're not sure how to find a doctor or get an AIDS test, you can contact the National AIDS Hotlines at (800) 342-AIDS (English) or (800) 344-7432 (Spanish). A specialist there will explain what you should do next.

There is no cure for AIDS, which makes prevention so important. Combinations of antiviral drugs and drugs that boost the immune system have allowed many people with HIV to resist infections, stay healthy, and prolong their lives, but these medications are not a cure. Right now there is no vaccine to prevent HIV and AIDS, although researchers are working on developing one.

Reviewed by: Steven Dowshen, MD

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