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AIDS In Detail Essay Research Paper Acquired (стр. 2 из 2)

about to show its versatility by appearing in several new population groups.

Indeed, epidemiologists were anticipating this development. If the new syndrome

could be spread by sex between two men, they asked themselves, might it also be

transmitted by sex between a man and a woman? And if it could be spread by blood

on contaminated needles used by heroin addicts, could it be spread by blood used

for medical purposes, such as during surgery? The answers to both questions

turned out to be affirmative. Between the end of 1981 and the end 1982, several

new groups were rapidly identified who were at greatly increased risk for

contracting AIDS. They were as follows: *Women who had sex with men who had the

AIDS infection. *Babies born to women infected with the AIDS virus.

*Hemophiliacs who injected blood products containing a clotting factor. *Surgery

patients who were transfused with contaminated blood. *Newly arrived immigrants

from Haiti and their sexual contacts. In each instance, transmission was either

sexual contact or through receiving infected blood. It is essential to recognize

that as each risk group was identified, it fit one of these patterns of

transmission. There was no group of unexplained AIDS cases that could have been

spread by casual contact, such as being sneezed on by person with AIDS or eating

food prepared by a person with AIDS. From May 1981 to the present, all evidence

has confirmed that AIDS is spread only by intimate contact, not by the

day-to-day, public encounters we all have in our business and social lives. But

with the regard of the two ways that AIDS is transmitted, blood and sex, it is

clear the illness does not select particular groups to afflict. It does not

matter if you whether you are a man or women, or what type of lifestyle you

practice. If you are injected or transfused with contagious blood or take into

your body other contagious bodily fluids, such as vaginal secretions or semen,

you run a high risk of getting AIDS. Minute amounts of these fluids pose very

little threat to transmitting the virus, and most nongenital fluids, such as

saliva, are currently thought to pose no risk whatsoever of transmitting it.

There is, however, a theoretical risk involved when any fluid is passed from an

infected person, though the relative risk is extremely small. Research is still

being done to prove these conjecture. 80 percent of babies HIV positive did not

develop AIDS although, their mother had AIDS. HEMOPHILIACS There are several

diseases in which the blood does not clot properly. Those born with these

conditions lack one of the many elements in the blood that are essential to stop

bleeding. Hemophilia A is an inherited clotting disorder that afflicts men

almost exclusively. In a person with severe hemophilia A, internal bleeding or

bleeding into joints can lead to serious complication, possibly even death. Even

small cuts clot slowly. It was persons with severe hemophilia A who were at

highest risk to get AIDS. To control their bleeding tendency, hemophiliacs

inject themselves with a concentrated preparation made from the blood of persons

with normal clotting ability. This preparation, called Factor VIII, is credited

with increasing the life expectancy of hemophiliacs in the last two decades from

35 to 55 years old. Some hemophiliacs have a mild disorder and use Factor VIII

only when they actually have a bleeding episode. But all hemophiliacs depend on

it at some point. Factor VIII, which was life saving for hemophiliacs, suddenly

turned to be an instrument of death. The preparation is made by pooling blood

collected from 2,000 to 5,000donors, then concentrating it, quick-drying it, and

putting it in vials. Because so many people’s blood was represented in each vial

of Factor VIII, the possibility existed that at least one donor had AIDS or was

harboring the AIDS organism-especially because drug users (until concerns were

raised about infected donors) often sold their blood for cash. And because each

hemophiliac uses 20, 30, or 40 vials of Factor VIIII each year, there was a good

chance that he would encounter a contaminated vial sooner or later. IDENTIFYING

THE VIRUS In particular, no known infectious agent was capable of producing the

specific destruction of the immune system that AIDS causes. Underlying all the

symptoms of AIDS is one primary defect: loss of a pivotal type of white blood

cells called the T4 helper lymphocyte(The role of T4 lymphocytes is to help

other types of immune cells become active and do their job. Without the T4

helper cells, the immune system virtually shuts down. And in some AIDS patients

there was an almost complete loss of T4 helper cells. Viruses are the most

minute form of life. Some people would not even call viruses living organisms.

They are many times smaller than bacteria, the other cause of human infectious

disease. Whereas bacteria are independent, able to grow and reproduce outside

cells of the organism they infect, viruses are parasites. In order to make more

of their kind, viruses must enter the cells of the creature they infect and take

over the cellular machinery. They subvert its productive power by making more of

their own kind. The cell dies, but the virus thrives. The virus is an

intracellular parasite because it’s structure, unlike that of a bacterium, is

too rudimentary to sustain itself-it must live within another cell (Bacteria are

internally complex, containing all the equipment necessary for life). Viruses

contain only the genetic material necessary to propagate themselves and a

tightly wrapped protective coat of proteins. These differences lead to a crucial

medical distinction between bacteria and viruses. Twentieth-century medical

science has developed many antibiotics drugs, such as penicillin, to combat

bacterial infections. But viruses are more difficult to kill. Because they

reproduce inside of our own cells, it is difficult to find a drug to stop the

virus from reproducing without harming the host cell. Progress against diseases

caused by viruses-such as small pox, mumps, measles, and polio-has come through

vaccines, which prevent infections. Latency, means that the infection stays in a

person’s body for a while before it causes clinical illness. Because viruses can

lie dormant 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.