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What Causes AIDS?

Acquired immunodeficiency syndrome (AIDS) is a chronic and potentially life-threatening condition caused by the human immunodeficiency virus (HIV). By damaging your immune system, HIV interferes with your body's ability to fight the organisms that cause disease. HIV is a sexually transmitted infection (STI). It can also be spread by contact with infected blood or from mother to child during pregnancy, childbirth or breast-feeding. Without medication, it may take years before HIV weakens the immune system to the point that a person has AIDS. There's no cure for HIV/AIDS, but there are medications that can dramatically slow the progression of the disease. These drugs have reduced AIDS deaths in many developed nations. Here is what you need to know about AIDS.

Causes

HIV is a retrovirus that infects some vital organs and cells of the human immune system. The virus progresses in the absence of antiretroviral therapy (ART). That is a drug therapy that slows or prevents the virus from developing. The rate of virus progression varies widely between individuals and depends on many factors. These factors include the age of the individual, the body's ability to defend against HIV, access to healthcare, the presence of other infections, the individual's genetic inheritance, resistance to certain strains of HIV, and much more.

How does HIV become AIDS?

HIV destroys CD4 T cells which are white blood cells that play a big role in helping your body fight disease. The fewer CD4 T cells you have, the weaker your immune system becomes. You can have an HIV infection for years before it turns into AIDS. Also, AIDS is diagnosed when the CD4 T cell count falls below 200 or you have an AIDS-defining complication.

How HIV spreads

To become infected with HIV, infected blood, semen or vaginal secretions must enter your body. This can happen in several different ways:

  • By having sex. You may become infected if you have vaginal, anal or oral sex with an infected partner whose blood, semen or vaginal secretions enter your body in that way. The virus can enter your body through mouth sores or small tears that sometimes develop in the rectum or vagina during sexual activity.
  • From blood transfusions. In some cases, the virus may be transmitted through blood transfusions. American hospitals and blood banks now screen the blood supply for HIV antibodies, so the risk is very small.
  • By sharing needles. Sharing contaminated intravenous drug paraphernalia (needles and syringes) puts you at high risk of HIV and other infectious diseases, such as hepatitis.
  • During pregnancy or delivery or through breast-feeding. Infected mothers can pass the virus on to their babies. HIV-positive mothers who get treatment for the infection during pregnancy can significantly lower the risk to their babies.

Where Is It Widespread?

Sub-Saharan Africa has the greatest number of people who are infected. The World Health Organization and the United Nations' UNAIDS office estimate that more than a third of adults are infected with HIV in some areas of Africa. The numbers of people who have HIV in Eastern Europe and in some parts of Asia are growing because of injection drug use. There are two main types of the virus: HIV-1 and HIV-2. HIV-2 is most commonly found in West Africa, although places in other parts the world are seeing it, too. HIV tests usually look for both kinds.

If you fall into any of the categories above, you should definitely consider being tested for HIV. Health care workers are at risk on the job and should take special precautions. Some health care workers have become infected after being stuck with needles containing HIV-infected blood after infected blood comes into contact with an open cut or through splashes into the worker's eyes or inside their nose. Even with treatment, some people seem to naturally experience a more rapid course towards AIDS. However, majority of HIV patients who receive appropriate treatment do well and live healthy lives for years.