AIDS In Detail Essay Research Paper Acquired — страница 6

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inside cells, they can have long latency periods. The latency periods for AIDS-the time between exposure to the infection and the first symptoms-may be as long as eight years, but it is usually three to five years. In children the latency is much shorter, and in women it may be shorter than in men. Persistence refers to how long the infectious agent remains after it starts the disease. With AIDS it is most likely that the agent stays for the person’s remaining lifetime. Despite treatment of each opportunistic infection, the immune system remains impaired. As fast as new immune cells are made they are destroyed. One tentative conclusion is that a viral ancestor of HIV evolved in Africa millions of years ago and affected monkeys. Gradually it changed to the form of HIV we see

today. But this still does not explain why the virus suddenly started causing human disease in the last quarter of the 20th century. THE OFFICIAL U.S. DEFINITION OF AIDS There are two factors which determine the category: T-cell count and history of disease of symptoms. The T-cell (officially called CD4lymphocyte) is the vulnerable immune system cell the HIV virus attacks, then uses as a breeding ground. Eventually, the T-cells killed by the virus. As a person’s T-cell count decreases, the risk of severe disease, or "opportunistic illness", increases. The three official levels of T-cell counts are: Level 1: a T-cell count greater than 500cells/ml Level 2: a T-cell count between 200-499 cells/ml Level 3: a T-cell count less than 200 cells/ml These categories are based

on the lowest T-cell count registered by a person. For example, someone who once tested at 180 but later received a boost in T-cells from a new protease inhibitor would still be considered level 3. To determine the three official government classifications, symptoms are also a factor. For example, a patient is in AIDS category 1 if he or she is asynmptomatic (no symptoms) and has a level 1 T-cell count. An AIDS category 2 patient has a level 2 T-cell count and at least one of the early stage illness but has not developed a later-stage disease, such as pneumonia or Kaposi’s sarcoma. In category 3-full-blown AIDS-the T-cell count has dropped below 200 and the patient has developed a later-stage disease. TREATMENT BREAKTHROUGHS There have been so many attempts to find a solution

to end with AIDS but it’s too complex and we know little of it, therefore it’s difficult to find a solution. Although, many experiments have been made for example the cocktail. It’s a treatment of vaccines that combine with an AZT. However, this vaccines does work for some but for others it does not do anything. Yet, the newest discovery is that some people are born with a certain type of gene that does not develop AIDS but has the virus. So this person may pass on the Virus and have it himself but it will not affect him at all.