AIDS

AIDS stands for Acquired Immuno-Deficiency Syndrome, and is a disease caused by infection with the Human Immunodeficiency Virus (HIV). HIV attacks the human immune system by destroying a type of white blood cell (T cells or CD4 cells) that the immune system must have to fight disease.

It can take years for a person infected with HIV, even without treatment, to develop AIDS. Having AIDS means that the virus has weakened the immune system to the point at which the body has a difficult time fighting infections. When someone has one or more of these infections and a low number of T cells, he or she has AIDS.

Origin

Scientists have identified a type of chimpanzee in West Africa as the source of HIV infection in humans. The virus most likely jumped to humans when humans hunted these chimpanzees for meat and came into contact with their infected blood. Over several years, the virus slowly spread across Africa and later into other parts of the world.

Transmission

HIV is a fragile virus. It cannot live for very long outside the human body. As a result, the virus is not transmitted through day-to-day activities such as shaking hands, hugging, or a casual kiss. Transmission can not occur from contact with toilet seats, drinking fountains, doorknobs, dishes, drinking glasses, food, pets, or insect bites.

HIV is primarily found in the blood, semen, or vaginal fluid of an infected person, and is transmitted in 3 main ways:

• Having unprotected sex (anal, vaginal, or oral) with someone infected with HIV
• Sharing needles and syringes with someone infected with HIV
• Being exposed (fetus or infant) to HIV before or during birth or through breast feeding

HIV also can be transmitted through blood infected with HIV. However, in developed countries, the risk for HIV infection through the transfusion of blood or blood products is extremely low, as supplies and/or donors are screened for infection.

Preventing Transmission

The risk of contracting HIV or passing it to someone else can be minimised by:

• Abstaining from sex
• Restricting the number of sexual partners, the fewer partners, the lower the risk
• Using latex condoms and lubricant during sex
• Using only clean needles and syringes when injecting
• Exercising caution in the handling of any human blood

The United States Centers for Disease Control and Prevention recommends these ABCs:

A=Abstinence

B=Be Faithful

C=Condoms

Symptoms

Many people who are infected with HIV do not have symptoms for many years. Someone can look and feel healthy but can still be infected. In fact, one quarter of the HIV-infected persons in the United States do not know that they are infected.

The following may be warning signs of advanced HIV infection:

• rapid weight loss
• dry cough
• recurring fever or profuse night sweats
• profound and unexplained fatigue
• swollen lymph glands in the armpits, groin, or neck
• diarrhea that lasts for more than a week
• white spots or unusual blemishes on the tongue, in the mouth, or in the throat
• pneumonia
• red, brown, pink, or purplish blotches on or under the skin or inside the mouth, nose, or eyelids
• memory loss, depression, and other neurological disorders

However, each of these symptoms can be related to other illnesses. The only way to determine whether a person's infection status is by testing for HIV infection.

HIV Testing

Once HIV enters the body, the body starts to produce antibodies — substances the immune system creates after infection. Most HIV tests look for these antibodies rather than the virus itself. There are many different kinds of HIV tests, including rapid tests and home test kits.

Source

http://www.cdc.gov/hiv/topics/basic/index.htm#aids