Aids (4346 words)

AidsAcquired immunodeficiency syndrome (AIDS). Today, despite the continuing production of better antibiotics since the discovery of penicillin, we are facing an infectious disease against which all these drugs are virtually powerless. This disease is spreading inexorably, killing more people and more people each year. AIDS does not know no national boundaries and does not discriminate by race or sex. It is rampaging not only throughout the United States, but also through Africa, India, China, Russia, Europe, South America, and the Caribbean countries. Even infants and children are at risk. AIDS is similar to the bubonic plague or the BLACK DEATH that killed perhaps one-third in Europe in the 14th century. Yet, the difference from the Black Death and AIDS is that it is in slow motion because the infectious agent that causes AIDS can remain dormant in a person’s body for several years before it causes illness, and because death from AIDS can be slow and drawn out once symptoms appear.

AIDS is essentially a disease of the immune system. The body’s defenses are destroyed and the patient becomes prey to the infections and cancers that would normally be fought off without any trouble. In 1984 it was proved that AIDS is caused by the human immunodeficiency virus (HIV). A virus is a minute infectious particle that enters and kills the immune cells, or lymphocytes. Because it destroys the very mechanism humans rely on for protection, prior to 1996 contracting Aids was considered a death sentence. For many years, 85 to 90 percent of all AIDS patients died within three years. They might have recovered from one infection only to succumb to another a few months later. Between infections they remain weak, emaciated and unable to work or carry on normal activities. In late 1996, almost 15 years after the first reported AIDS cases, researchers made the discovery that a certain combination of newly developed drugs could substantially prolong life in some AIDS patients. But AIDS is a fiendish virus. When researchers cleared it out of a patient’s bloodstream, it hid in the lymph nodes. Scientists, figured out how to banish it from the lymph nodes, they found the virus lurking in the brain. Although, there is hope for a cure because they have done some experiments isolating a gene and it has had good results in some people infected with AIDS. The area that many people are concerned is with Southeast Asia-particularly India. At 900 million, India’s population is almost double that sub-Saharan Africa, which, with 13.3 million HIV-positive adults, accounts for 60 percent of the world’s total adult infections.
The major reasons for such spread in India and following Africa is the high rate of their population, poverty rate, and other risk factors all point to a likely explosion. The number of HIV infections worldwide doubled between 1991 and 1996-and that number is expected to double again by the year 2000. By the turn of the century, about 44 million people will have fallen victim to the virus that causes AIDS. The signs of hope do not stop by the reason of Prevention Programs which they have succeeded in reducing HIV-infection rates dramatically among young men in Thailand and young women in Uganda-two of the countries hit hardest by the3 disease. The rate of new infections have also dropped sharply among gay men in the United States, Australia, Canada, and western Europe.

However, many ingredients of the AIDS epidemic are still mystery. The cause of AIDS remained uncertain for several years after its discovery. Even now, there are questions about how efficiently the AIDS virus spreads, whether it will kill everyone who gets it, and why the virus is do devastating to the immune system. It’s initial spread was in the United States was among groups that are frowned upon by society-homosexuals and intravenous(drug users)- AIDS has a stigma associated with it. This makes the disease difficult to confront rationally. However, people are terrified even by the word of AIDS. The virus does not get transmitted by any body contact neither through the air. However, the disease does not pass from one person to another through the air, by sneezing, on eating utensils, by shaking hands, or through body contact in sports. There are only four ways it can be spread: through injection with a needle contaminated with HIV, which it can happen when drug addicts share needles; by receiving a transfusion of contaminated blood; or-in the case of infant with an HIV-positive mother-having the virus transmitted through the placenta before birth, or the mother’s milk after birth.

For years, some people to refused to admit AIDS was a problem. Although, the disease first received national attention in 1982, when the Centers of Disease Control (CDC) noticed an alarming rate of rare cancer (Kaposi’s sarcoma) in otherwise healthy gay men.

SOUNDING THE FIRST ALARM
Three patients examined by Dr.Gottlieb were very ill. Interestingly, they had several striking features in common. All had unusual infections such as thrush, which is the growth in the throat of a fungus called Candida; or a rare type of pneumonia caused by a parasite called Pneumocystis. Also, they had been infected by less-common viruses, such as Epstein-Barr virus, which causes mononucleosis, or by cytomegalovirus (CMV). Taken together, the infections pointed to a serious defect in the patients’ immune systems.

Sure enough, when Dr. Gottlieb drew a vial blood from each patient and measured special kind of immune cell called a T-helper lymphocyte, all three patients’ tests gave the same startling result. They were virtually devoid of T-helper cells, Dr. Gottlieb found. It was clear that they had seriously deficient immune systems.

The three men had something else in common: they were all homosexuals. At that time it was not clear that the patients’ homosexuality was related to the illness; a patients’ sexual preference had never before been considered the determining factor of a medical disorder. That situation was about to change radically.

SIGNS AND SYMPTOMS OF AIDS
Early symptoms of HIV, lasting between one and four weeks, can mimic that of mononucleosis, with symptoms such as swellings of the lymph nodes, headache, fever, loss of appetite, weight loss, sweating and sore throat. Often of these symptoms are mistaken for the flu or another viral-type infection, so people may not even be aware that they have been infected with HIV. Even if the patient has seen a doctor, the physician may dismiss the symptoms as a viral infection. In nearly all the cases, this stage dissipates due to the healthy immune system’s ability to fight the initial infection. Early symptoms may include:
*Herpes zoster (shingles), a skin rash that appear on the chest, abdomen, and/or back.

*Herpes simplex, a common sexually transmits disease that affects the rectal, genital, esophageal regions of the body. Painful lesions can erupt into ulceration’s of the area. In HIV/AIDS patients, this may become a chronic condition.

*Thrush, a white coating on the walls of the mouth, gums, and on the tongue, that is caused by a fungus called Candida Albicans.

*Excessive bruising and bleeding that occurs when a person develops antibodies which attack the body’s platelets-cells which help blood to clot. This condition can go unnoticed, and is often not detected until a routine blood test is performed.

*Chronic or intermittent diarrhea, found both in early and late stages of HIV infection.

As the immune system becomes increasingly compromised, the body is not able to fight off more serious infections that a normal intact immune system could suppress. Some of these life threatening infection include:
*Pneumocystis pneumonia (PCP), caused by parasite called pneumoncytis carinii. Symptoms include fever and respiratory complications that often lead to death.

*Kaposi’s sarcoma, a condition in which tumors of the blood vessels develop on the skin, in the gastrointestinal tract, mouth, lungs, groin, brain liver, and lymph glands. The mall, nonpainful lesions usually are a red, brown, or purple color.

*Tuberculosis (TB), which can occur in both early and late stages of HIV. Symptoms include night sweats, fever, cough, and weight loss. One of the major problems with this aspect of the disease is the development of TB strains resistant to drugs, making it harder and harder to treat.

*Mycobacterium avium complex, which produces fatigue, chills, night sweats, fever, weight loss, diarrhea, and abdominal pain.

*HIV related lymphoma, swollen lymph glands in the neck, groin region, or under the arms. This requires radiation and chemotherapy treatment.

*Toxoplasmosis encephalitis, caused by a parasite, which produces an infection in the brain leading to neuro logical impairment and seizures. Symptoms include headaches, fever, lethargy, confusion, and loss of balance or coordination.

*Cytomegalovirus (CMV) infection, a viral infection distributed to all parts of the body through bloodstream and causing infections in the eyes, lungs, and other organs. About 90 percent of AIDS patients eventually develop cytomegalovirus.

*Crytococcosis. Produced by a fungus found in the soil. This causes a brain infection. Symptoms include fatigue, fever, nausea and vomiting, altered mental state, memory loss, confusion, and behavioral changes.

*Crytosporidosis, an infection developed drinking and contaminated water, produces severe diarrhea and weight loss.

KAPOSI’S SARCOMA
If the infectious disease specialists were puzzled, several New York dermatologist were even more perplexed. These doctors, who specialize in skin diseases, were seeing a number of patients with an extremely rare kind of cancer called Kaposi’s sarcoma spot on the skin, further examination reveals the presence of the cancer in an internal organ, such as the stomach, as well.

Kaposi’s sarcoma had been a disease of elderly men in the Mediterranean origin; in New York City it began to appear in young men of every ethnic background. It had been known as a slow-growing cancer that could be treated successfully; in these new, young patients the sarcoma was spreading fast and damaging internal organs.

A cancer of the skin and internal organs does not sound like it would be related to rare infections of the lung and the brain. But there is a strong connection-the immune system. It is one of the principles of the science of immunology that immune cells are essential in protecting the body from tumor cells. If a small colony of cancers, a tumor, become established, lymphocytes (part of the immune system) are supposed to find it and destroy it before it can grow. So Kaposi’s sarcoma in these young gay men could be seen as opportunistic cancer, taking advantage of the breakdown in the patients’ defenses, just as the infectious organisms were doing.

There was also a more concrete reason for the doctors to know that the cases of Kaposi’s sarcoma in young gay men signaled a breach of these person’s protective mechanisms: Kaposi’s is relatively common in patients whose immune systems were surprised by medical treatment. Patients taking drugs that suppress the immune system are also prone to lymphoma, or cancer of the immune system, Soon this cancer started showing in gay men, too.

WHY HOMOSEXUALS?
Dr. Currant’s statement implied two things. One, that there was an infectious organism underlying the unusual diseases (perhaps an infectious organism that attacked the immune system). Two, that the homosexual lifestyle was somehow unique. It would be three years before the suspicion of an infectious agent that attacked immune cells was verified by the isolation of the AIDS virus. But it was already known that gay men’s sexual habits differed from those of the most heterosexuals. They found that two other diseases were very common in homosexual men and that are sexually transmitted-hepatitis B and gonorrhea. The first thought was that the occurrence of the Pneumocystis pneumonia and Kaposi’s sarcoma in homosexual men might involve sexual transmission. The men with Kaposi’s reported having an average of 61 different partners in the previous year; the public clinic patients and the men from private physicians said they had had 25 different sexual partners in the past year. Both of these numbers are much higher than the two to five sexual partners per year common among nonmonogamous (sexually active with more than one partner)heterosexuals. The ill men reported contacting a much higher percentage of their partners in gay baths, public places where gay men can go for anonymous sex. The men with Kaposi’s had met with half of their partners in the baths; the clinic patients had made one-fourth of their sexual contacts in the baths; and the healthy private patients averaged only one anonymous partner per year.

Homosexual men have higher rates of sexually transmits diseases than heterosexual men and women because gay men tend to have larger numbers of different sexual partners, more often engage in furtive (anonymous) sexual activities, and more frequently have anal intercourse.

PUZZLING SYMPTOMS
Any theory of the new disease also had to account for a puzzling factor: the variety of symptoms seen in AIDS patients before they entered the final phase of complete susceptibility to opportunistic infections and cancers. Interviews with AIDS patients revealed many had been very sick for up to a year before they developed their first case of Pneumocystis pneumonia or showed their first Kaposi’s spot, both signs of AIDS.
One form of illness that preceded outright AIDS was a state called lymphadenopathy syndrome, or as LAS, in which the patient had several swollen lymph nodes for three months or more. These swollen lymph nodes might be in the neck, in the throat, or under the armpits. Swollen lymph nodes are a sign that the immune system is fighting an infection. Did any patients with swollen lymph nodes get better, indicating a successful fight? Or was the struggle always futile? Several physicians recruited patients with LAS and examined them every few months to learn the answer.

A more serious condition was AIDS-related complex (ARC), a stage of the illness no longer considered separately. It had been defined in 1983 as the presence of two or more unexplained clinical symptoms of AIDS and at least two abnormal lab tests for the related signs. Patients with ARC might lose a large amount of weight, have frequent fevers, sweat a lot at night, feel very fatigued, and suffer untreatable diarrhea. It seemed that the presence of ARC signaled that outright AIDS was inevitable. But what phase of the AIDS disease process did ARC represent? The Center for Disease Control never officially recognized ARC for it’s reporting purposes, but the term was useful in describing what appeared to be on the set of AIDS. Better terminology has followed from medical advances, however, and the symptoms of what was called ARC are viewed as just another of the AIDS-related illness rather than as a distinct stage of the disease.

INTRAVENOUS DRUG USERS
Heroin addicts have an illegal habit and are dedicated primarily to getting their next fit. Many do not stay in one place long enough to be studied. Most of them would rather use their money for drugs than for medical care, so they do not often enter the traditional medical system. Hence, relatively, little is known about the medical condition of those who populate the drug culture.

Striking a needle into your vein after someone else has used it is an easy way to get any infectious diseases that the other person may have. It is like giving yourself a transfusion of infected blood. That is why IV drug users have a high rate of hepatitis, a blood disease that is lethal if left untreated. That is why they become the second group among whom AIDS rapidly spread. Within a year of the onset of the epidemic, almost 20% of AIDS patients were found to be IV drug users. But most IV drug users are heterosexuals. Many female addicts resort to prostitution to support their habit. An infected prostitute can spread AIDS to any of her customers, and those men can spread it to any women or men they later have sex with. Former addicts can also transmit AIDS to any person they have a sexual relationship with, if they acquired the AIDS infection while they are using drugs.

From these mysterious and frightening beginnings among gay men and IV drug users, AIDS was 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 CD4+T-lymphocyte) 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.

TABLE OF CONTENTS
1-INTRODUCTION
2-WHAT IS AIDS?
3-WHAT ARE THE SIGNS AND SYMPTOMS OF AIDS
4-KAPOSI’S SARCOMA
5-WHY HOMOSEXUALS?
6-PUZZLING SYMPTOMS
7-INTRAVENOUS DRUG USERS
8-HEMOPHILIACS
9-IDENTIFYING THE VIRUS
10-THE OFFICIAL U.S. DEFINITION OF AIDS
11-TREATMENT BREAKTHROUGHS
BIBLIOGRAPHY
– Check, William. The Encyclopedia of Health AIDS. Chelsea House Publishers; Philadelphia: 1999
– Encarta Encyclopedia 97AIDS Microsoft Windows.

– Center For AIDS Prevention Studies:www.caps.ucsf.edu(March 1, 2000)
– JAMA HIV/AIDS Information center:www.ama.assn.org/special/hivhome.htm
(March 1,2000)
– International Association Of Physicians in AIDS Care:www.iapac.org/ (March 1,2000)
Science Essays