Jumat, 07 Mei 2010

Acquired Immune Deficiency Syndrome

For almost 30 years, health officials have struggled to contain AIDS, which is now known to be the end result of HIV infection.

Acquired immune deficiency syndrome (AIDS) is a syndrome of opportunistic and rare diseases caused by the eradication of the immune system by the human immunodeficiency virus (HIV). A diagnosis of AIDS is made when a person tests positive for HIV, has a low white blood cell count, and suffers from a range of opportunistic infections that take advantage of the immune deficiency caused by HIV. People sometimes refer to HIV as the AIDS virus because the visible manifestation of HIV infection is the range of opportunistic infections known as AIDS.
HIV Transmission

HIV infection occurs when body fluids are transferred from an infected individual and another individual. The most common means are blood to blood via shared needles, semen and vaginal secretions between partners during sexual interactions, and breast milk from mother to child. Also, different strains of HIV are better able to be transmitted in different ways.

Example: HIV-1M (Major) clade e excels at being taken up by vaginal dendritic cells, which is facilitated by inflammation, particularly in the context of other sexually transmitted diseases (STDs).
The Course of HIV Infection Ending in AIDS

The AIDS virus infects immune cells, including T cells and dendritic cells. The virus infects T cells by attaching to surface proteins and injecting its genetic material and the enzymes necessary for its propagation in the cells. Upon the initial exposure to HIV, the immune system responds to fight off the infection, and flu like symptoms are common. This initial response, though mostly futile on the part of the body, is condiered the early, or acute, stage of HIV infection.

The virus can lie dormant within the immune cells for years, sometimes decades. This period of time is considered the middle, or chronic, stage of infection. During this time, the virus increases its numbers while residing safely within the cells of the very system meant to destroy it. Eventually, the virus numbers increase beyond the capacity of the host cell and burst out to infect even more T cells. When the immune system becomes alerted and attempts to fight off the infection, T cells are activated, resulting in even more viral particles.

After several years, the time frame varies based on the patient and strain, so few immune cells are left that the infected individual is not protected against new or common infections. These opportunistic infections defined the syndrome known as AIDS, the final, or crisis, and fatal stage of HIV infection.
Read on

* The Four Stages of HIV Infection
* The 2008 Nobel Prize in Medicine
* The HIV Virus

Antiretroviral medications stop the virus from propagating, holding it in a perpetual state of dormancy. This dormancy postpones the immune system breakdown, increasing the life span of the infected individual by 10 years or more. Twenty years ago, patients were found to succumb to AIDS within 5 years of left untreated.
Dissenting Opinions about AIDS and HIV

The International AIDS Society, which represents more than 11,000 professionals worldwide that work with HIV, publicly opposes the efforts of AIDS deniers, the term given to those who question that HIV causes AIDS. The dissenting opinions point to studies performed before retrovirus research discerned the mechanism of HIV infection and the course of disease. The anti-HIV/AIDS movement blames homosexuals and drug-users for the disease. Denier groups, such as Alive and Well, teach that anal sex, stress, and long-term drug use results in the immune deficiency syndrome. Such initiatives endanger individuals by propagating the idea that HIV prevention is unnecessary and that anti-retroviral medications are not necessary, or even the cause of the disease themselves.
HIV Testing

HIV infection is most commonly determined by an antibody test, the classic method of determining exposure. There is also now an RNA test that detects the presence of HIV by directly testing for its genetic material. Regardless of which test is used, a positive result is always followed by another test for confirmation. Beginning pharmaceutical therapy soon after diagnosis is so far the best means to keep AIDS at bay.

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