Sunday, November 15, 2015

DR ROBERT GALLO WAS COMMISSIONED TO MANUFACTURE A DEADLY DISEASE TO DEPOPULATE BLACKS WORLDWIDE AND HE DID FOR TEN YEARS WITH HIS ASSOCIATES.

AGUNABU UMUELECHI BIAFRA ULTIMATE DIATRIBE ON THE POLITICS OF HIV-AIDS



Dr Jideofo Kenechukwu Danmbaezue, D.Sc.

Can someone explain why the entries in the 1988 version of Microsoft Encarta encyclopaedia on Acquired Immunodeficiency Syndrome and that of the 2004 version are very different? Why was the detailed history of the development of the virus absent in the latter version? If there is no ulterior motive for this discrepancy, then let someone interpret the etymological meanings of the words: ‘isolated', ‘discovered' and ‘invented' in common day usage of the words! What does each imply?

  


BY THE ANIMATOR OF HAFANI RESEARCH CONSORTIUM @ UNIVERSITY OF NIGERIA, ENUGU @ 19:38:28 HRS GMT on Thursday, 12 November 2015


Acquired Immune Deficiency Syndrome (AIDS), specific group of diseases or conditions that result from suppression of the immune system related to infection with the human immunodeficiency virus (HIV). A person infected with HIV gradually loses immune function along with certain immune cells called CD4 T-lymphocytes or CD4 T-cells, causing the infected person to become vulnerable to pneumonia, fungus infections, and other common ailments. With the loss of immune function, a clinical syndrome (a group of various illnesses that together characterize a disease) develops over time and eventually results in death due to opportunistic infections (infections by organisms that do not normally cause disease except in people whose immune systems have been greatly weakened) or cancers.

In the early 1980s deaths by opportunistic infections, previously observed mainly in organ transplant recipients receiving therapy to suppress their immune responses, were recognized in otherwise healthy homosexual men. In 1983 French cancer specialist Luc Montagnier and scientists at the Pasteur Institute in Paris isolated what appeared to be a new human retrovirus-a special type of virus that reproduces differently from other viruses-from the lymph node of a man at risk for AIDS (see Lymphatic System). Nearly simultaneously, scientists working in the laboratory of American research scientist Robert Gallo at the National Cancer Institute in Bethesda, Maryland, and a group headed by American virologist Jay Levy at the University of California at San Francisco isolated a retrovirus from people with AIDS and from individuals having contact with people with AIDS. All three groups of scientists isolated what is now known as human immunodeficiency virus (HIV), the virus that causes AIDS.
Infection with HIV does not necessarily mean that a person has AIDS, although people who are HIV-positive are often mistakenly said to have AIDS. In fact, a person can remain HIV-positive for more than ten years without developing any of the clinical illnesses that define and constitute a diagnosis of AIDS. In 1996 an estimated 22.6 million people worldwide were living with HIV or AIDS-21.8 million adults and 830,000 children. The World Health Organization (WHO) estimates that between 1981, when the first AIDS cases were reported, and the end of 1996, more than 8.4 million adults and children had developed AIDS. In this same period there were 6.4 million deaths worldwide from AIDS or HIV. About 360,000 of these deaths occurred in the United States.


Clinical Progression of AIDS
The progression from the point of HIV infection to the clinical diseases that define AIDS may take six to ten years or more. This progression can be monitored using surrogate markers (laboratory data that correspond to the various stages of disease progression) or clinical endpoints (illnesses associated with more advanced disease). Surrogate markers for the various stages of HIV infection include the declining number of CD4 T-cells, the major type of white blood cell lost because of HIV infection. In general, the lower the infected person's CD4 T-cell count, the weaker the person's immune system and the more advanced the disease state. In 1996 it became evident that the actual amount of HIV in a person's blood-the so-called viral burden-could be used to predict the progression to AIDS, regardless of a person's CD4 T-cell count. With advancing technology, viral burden determinations are quickly becoming a standard means of patient testing.
An infected person's immune response to the virus-that is, the person's ability to produce antibodies against HIV-can also be used to determine the progression of AIDS; however, this surrogate marker is less precise during more advanced stages of AIDS because of the overall loss of immune function.
Within one to three weeks after infection with HIV, most people experience nonspecific flulike symptoms such as fever, headache, skin rash, tender lymph nodes, and a vague feeling of discomfort. These symptoms last about one to two weeks. During this phase, known as the acute retroviral syndrome phase, HIV reproduces to very high concentrations in the blood, mutates (changes its genetic nature) frequently, circulates through the blood, and establishes infections throughout the body, especially in the lymphoid organs. The infected person's CD4 T-cell count falls briefly but then returns to near normal levels as the person's immune system responds to the infection. Individuals are thought to be highly infectious during this phase.
Following the acute retroviral syndrome phase, infected individuals enter a prolonged asymptomatic phase-a symptom-free phase that can last ten years or more. Persons with HIV remain in good health during this period, with levels of CD4 T-cells ranging from low to normal (500 to 750 cells per cubic mm of blood). Nevertheless, HIV continues to replicate during the asymptomatic phase, causing progressive destruction of the immune system.
Eventually, the immune system weakens to the point that the person enters the early symptomatic phase. This phase can last from a few months to several years and is characterized by rapidly falling levels of CD4 T-cells (500 to 200 cells per cubic mm of blood) and opportunistic infections that are not life threatening.
Following the early symptomatic phase, the infected person experiences the extensive immune destruction and serious illness that characterize the late symptomatic phase. This phase can also last from a few months to years, and the affected individual may have CD4 T-cell levels below 200 per cubic mm of blood along with certain opportunistic infections that define AIDS. A wasting syndrome of progressive weight loss and debilitating fatigue occurs in a large proportion of people in this stage. The immune system is in a state of severe failure. The person eventually enters the advanced AIDS phase, in which CD4 T-cell numbers are below 50 per cubic mm of blood. Death due to severe life-threatening opportunistic infections and cancers usually occurs within one to two years.
Opportunistic Illnesses
Death from AIDS is generally due not to HIV infection itself, but to opportunistic infections that occur when the immune system can no longer protect the body against agents normally found in the environment. The appearance of any one of more than 25 different opportunistic infections, called AIDS-defining illnesses, along with a CD4 T-cell count of less than 200 cells per cubic millimeter of blood provides the clinical diagnosis of AIDS in HIV-infected individuals.
The most common opportunistic infection seen in AIDS is Pneumocystis carinii pneumonia (PCP), which is caused by a fungus that normally exists in the airways of all people. Bacterial pneumonia and tuberculosis are also commonly associated with AIDS. In the late symptomatic phase of AIDS, bacterial infection by Mycobacterium avium can cause fever, weight loss, anemia, and diarrhea. Additional bacterial infections of the gastrointestinal tract commonly cause diarrhea, weight loss, anorexia (loss of appetite), and fever. Also, during advanced AIDS, diseases caused by protozoal parasites, especially toxoplasmosis of the nervous system, are common.
In addition to PCP, people with AIDS often develop other fungal infections. Thrush, an infection of the mouth by the fungus Candida albicans, is common in the early symptomatic phase of AIDS. Other infectious fungi include species of the genus Cryptococcus, a major cause of meningitis in up to 13 percent of people with AIDS. Also, infection by the fungus Histoplasma capsulatum affects up to 10 percent of people with AIDS, causing general weight loss, fever, and respiratory complications or severe central nervous system complications if the infection reaches the brain.
Viral opportunistic infections, especially with members of the herpes virus family, are common in people with AIDS. One herpes family member, cytomegalovirus (CMV), infects the retina of the eye and can result in blindness. Another herpes virus, Epstein-Barr virus (EBV), may result in a cancerous transformation of blood cells. Infections with herpes simplex virus (HSV) types 1 and 2 are also common and result in progressive sores around the mouth and anus.
Many people with AIDS develop cancers, the most common types being B-cell lymphoma and Kaposi's sarcoma (KS). Kaposi's sarcoma-a cancer of blood vessels that results in purple lesions on the skin that can spread to internal organs and cause death-occurs mainly in homosexual and bisexual men. Although the cause of KS is unknown, a link between KS and a new type of herpes virus was discovered in 1994.

Human Immunodeficiency Virus (HIV)
The causative agent of AIDS is HIV, a human retrovirus. Researchers have known since 1984 that HIV enters human cells by binding with a receptor protein known as CD4, located on human immune-cell surfaces. HIV carries on its surface a viral protein known as gp120, which specifically recognizes and binds to the CD4 protein molecules on the outer surface of human immune cells. However, in 1984 researchers found that CD4 by itself was not sufficient for HIV infection to take place. Some other unknown factor, found only in human cells, was also required. After much research, in 1996 scientists discovered that HIV must also bind to chemokine receptors, small proteins also found on the surface of human immune cells, to enter the cells. The first chemokine receptor linked to HIV entry was CXCR4 (originally called fusin), which is bound by HIV strains that dominate during the latter stages of the disease. Researchers then determined that another chemokine receptor, CCR5, bound HIV strains that dominate in the early stages of the disease. Researchers are continuously discovering more chemokine receptors.
Any human cell that has the correct binding molecules on its surface is a potential target for HIV infection. However, it is the specific class of human white blood cells called CD4 T-cells that are most affected by HIV because these cells have high concentrations of the CD4 molecule on their outer surfaces. HIV replication in CD4 T-cells can kill the cells directly; however, the cells also may be killed or rendered dysfunctional by indirect means without ever having been infected with HIV. CD4 T-cells are critical in the normal immune system because they help other types of immune cells respond to invading organisms. As CD4 T-cells are specifically killed during HIV infection, no help is available for immune responses. General immune system failure results, permitting the opportunistic infections and cancers that characterize clinical AIDS.
Although it is generally agreed that HIV is the virus that causes AIDS and that HIV replication can directly kill CD4 T-cells, the large variation among individuals in the amount of time between infection with HIV and a diagnosis of AIDS has led to speculation that other cofactors-that is, factors acting along with HIV-may influence the course of disease. The exact nature of these cofactors is uncertain-it is believed that they may include genetic, immunologic, and environmental factors or other diseases. However, it is clear that HIV must be present for the development of AIDS.
Modes of Transmission
HIV is spread through the exchange of body fluids, primarily semen, blood, and blood products. It is most commonly spread by sexual contact with an infected person. The virus is present in the sexual secretions of infected men and women and gains access to the bloodstream of the uninfected person by way of small abrasions that may occur as a consequence of sexual intercourse.
HIV is also spread by any sharing of needles or syringes that results in direct exposure to the blood of an infected individual. This method of exposure occurs most commonly among people abusing intravenous (IV) drugs (drugs injected into the veins).
HIV transmission through blood transfusions or use of blood-clotting factors is now extremely rare because of extensive screening of the blood supply; it is estimated that undetected HIV is present in fewer than 1 in 450,000 to 600,000 units of blood.
HIV can be transmitted from an infected mother to her baby, either before or during childbirth, or through breast-feeding. Although only about 25 to 35 percent of babies born to HIV-infected mothers worldwide actually become infected, this mode of transmission accounts for 90 percent of all cases of AIDS in children. In addition, even uninfected children born to HIV-infected mothers have an incidence of heart problems 12 times that of children in the general population.
In the health care setting, workers have been infected with HIV after being stuck with needles containing HIV-infected blood or, less frequently, after infected blood contacts the worker's open cut or splashes into a mucous membrane (for example, the eyes or the inside of the nose). There has been only one demonstrated instance of patients being infected by a health-care worker; this involved HIV transmission from an infected dentist to six patients. In general, infected health-care workers pose no risk to their patients. There is also no risk of contracting HIV infection while donating blood.
The routes of HIV transmission are well known, but unfounded fear continues concerning the potential for transmission by other means, such as casual contact in a household, school, workplace, or food-service setting. No scientific evidence to support any of these fears has been found. HIV does not survive well when exposed to the environment. Drying of HIV-infected human blood or other body fluids reduces the theoretical risk of environmental transmission to essentially zero. Additionally, HIV is unable to reproduce outside its living host; therefore, it does not spread or maintain infectiousness outside its host.
No cases of HIV transmission through the air, by casual contact, or even by kissing an infected individual have been documented. Researchers have recently identified a protein in saliva, known as secretory leukocyte protease inhibitor (SLPI), that prevents HIV from infecting white blood cells. However, practices that increase the likelihood of contact with the blood of an infected individual, such as open-mouth kissing or sharing toothbrushes or razors, should be avoided. There is also no known risk of HIV transmission to coworkers, clients, or consumers from contact in food-service establishments.
Studies have shown no evidence of HIV transmission through insects-even in areas where there are many cases of AIDS and large populations of insects such as mosquitoes. HIV lives for only a short time inside an insect and does not reproduce. Thus, even if the virus enters a mosquito or another sucking or biting insect, the insect does not become infected and cannot transmit HIV to the next human it feeds on or bites.
Occurrence
The nature of the AIDS epidemic is constantly evolving. In the United States, HIV infection was initially concentrated in the homosexual community-where widespread transmission occurred because of high-risk sexual behavior-and in people with hemophilia and other individuals receiving blood products. HIV infection then became established among people who abuse intravenous (IV) drugs and was spread by heterosexual contact (sexual relations between partners of the opposite sex) into all groups of society, especially through prostitution and other forms of high-risk sexual practices. Currently, homosexual interactions (sexual relations between men) account for about 50 percent of AIDS cases, and practices involving IV drug abuse account for about 26 percent. The heterosexual spread of AIDS in the United States, especially from infected males to previously uninfected females, is increasing rapidly and now accounts for 9 percent of transmissions.
Of the more than 580,000 AIDS cases reported in the United States between 1981 and 1996, about 46 percent have been in Caucasians, 35 percent in blacks, 18 percent in Hispanics, and 1 percent in Asians. Males make up about 84 percent of these cases and females 15 percent. Children account for the remaining 1 percent of AIDS cases. Women and children constitute one of the fastest-growing groups of people with AIDS. Through December 1996, 52 documented cases and 111 possible cases of occupational transmission of AIDS/HIV infection had been reported in health-care workers. In 1994 and 1995 AIDS was the leading cause of death among Americans aged 25 to 44 years, the leading cause of death for American men of the same age group, and the third leading cause of death among American women in that same age group.
On a global scale, the AIDS epidemic is rapidly expanding. Of the estimated 22.6 million people worldwide living with HIV or AIDS in 1996, about 62 percent were living in sub-Saharan Africa, 23 percent in southern and eastern Asia and the Pacific , 6 percent in Latin America, 5 percent in North America and the Caribbean, and 2 percent in Europe and Central Asia. In Asia and Africa, most people contract the disease through heterosexual contact.
The major strain of HIV in the United States, Europe, and central Africa is known as HIV-1. In western Africa, AIDS is also caused by HIV-2, a strain of HIV closely related to HIV-1. Other distantly related strains of HIV-1 have been identified in various areas of the world. Although some of these strains cannot be detected with current blood-screening methods, there is little risk of these viruses spreading to the United States because of their geographic isolation. Even in the case of HIV-2, spread outside Africa is rare. Only 64 cases of HIV-2 have been documented in the United States, and transmission in these cases was linked directly to western Africa.

Detection and Diagnosis
Although AIDS has been tracked since 1981, the identification of HIV as the causative agent was not made until 1983. In 1985 the first blood test for HIV, developed by the research group led by Robert Gallo, was approved for use in blood banks. This test can detect whether a person's blood contains antibodies against HIV, an indication of exposure to the virus. However, for about four to eight weeks after exposure to HIV, an individual will continue to test negative for HIV infection because the immune system has not had enough time to make antibodies against HIV. In 1996 an additional blood test was approved for use in blood banks. This test can detect HIV antigens-proteins produced by the virus itself. The test can thus identify HIV even before the donor's immune system has had a chance to make antibodies. An estimated 50 million blood samples are tested each year in the United States by blood banks, plasma centers, reference laboratories, private clinics, and health departments. Due to the major differences in the protein components of HIV-1 and HIV-2, separate tests were developed to detect these two related viruses. As new strains of HIV are identified from around the world, they will need to be evaluated for detection by these tests.
The Centers for Disease Control and Prevention (CDC) in Atlanta, Georgia, has established an authoritative definition for the diagnosis of AIDS: In an HIV-positive individual, the CD4 T-cell count must be below 200 cells per cubic mm of blood, or there must be the clinical appearance of an initial AIDS-defining opportunistic infection, such as PCP (Pneumocystis carinii pneumonia), oral candidiasis (thrush), pulmonary tuberculosis, or invasive cervical carcinoma (cancer of the cervix in women).
Treatment
Antiviral drugs that attack HIV exploit vulnerable spots in the viral replication cycle. One target is the process of reverse transcription-that is, the conversion of the viral ribonucleic acid (RNA) into deoxyribonucleic acid (DNA)-that HIV must undergo to be infectious. Reverse transcription is a process unique to retroviruses and is performed by the viral enzyme reverse transcriptase (RT). One class of anti-HIV drugs, known as nucleosides, are all RT inhibitors. Five nucleosides are currently licensed by the U.S. Food and Drug Administration (FDA): zidovudine (Retrovir, AZT), didanosine (Videx, ddI), zalcitabine (Hivid, ddC), stavudine (Zerit, d4T), and lamivudine (Epivir, 3TC). These drugs work as DNA-chain terminators. Because the drug appears to be a normal nucleotide base (the building block of DNA), the RT enzyme mistakenly inserts the drug into the growing viral DNA chain. Once the drug is inserted, no additional DNA bases can be added, and therefore viral DNA synthesis is terminated.
Although the nucleosides are more likely to interact with the viral RT enzyme, they also can be incorporated by the enzyme responsible for normal cellular DNA synthesis in the person receiving the drug, leading to toxicity (poisoning) and side effects. Such drug incorporation is usually observed in rapidly dividing cell types, such as the cells of the bone marrow, spongy tissue filling the cavities within bones.
A second problem is the emergence of drug-resistant forms of HIV in people receiving these drugs. Studies on early treatment of HIV infection with AZT have presented contradictory results as to whether such early treatment prolongs life. Because HIV replicates rapidly and mutates frequently during the earliest period of infection, an HIV-infected person carries many different strains of HIV, some of which may be drug-resistant. The limited variety of HIV in the early stage is thought to make it more susceptible to AZT and related drugs.
Although RT inhibitors were never considered a cure for HIV infection, it was hoped that they would slow the progression of AIDS, and AZT has been shown effective in reducing HIV transmission from pregnant women to their babies. However, the clinical benefit of RT inhibitors when used alone has been largely disappointing; they have extended the lives of people with AIDS by only about six months. When taken in conjunction with other RT inhibitors, however, they have been more effective. For example, AZT combined with lamivudine prevents the AIDS virus from developing resistance to AZT even though the virus quickly develops resistance to lamivudine. The combination also has been shown to boost CD4 T-cell counts and to lower levels of HIV in the blood. In November 1995 the FDA approved the combined use of AZT and lamivudine for early treatment of AIDS.
RT inhibitors are also effective when used with a new class of anti-HIV drugs known as protease inhibitors, approved by the FDA in December 1995. Protease inhibitors work by crippling a key viral enzyme called protease, which is vital to the reproduction of HIV in the later stages of its replication cycle.After HIV replicates-that is, makes copies of its own protein components-these proteins must be cut to specific sizes before they can assemble into a mature virus. Protease is responsible for trimming the new HIV proteins to their required dimensions. When protease is blocked-or inhibited-the proteins are not cut andthe defective HIV cannot infect new cells. The first protease inhibitor drug, saquinavir (Invirase), was approved for use in combination with nucleoside drugs such as AZT. In March 1996 two additional drugs, ritonavir (Norvir) and indinavir (Crivaxin), were rapidly approved for use alone or in combination with nucleosides. A fourth drug, nelfinavir (Viracept), was approved by the FDA in March 1997 for both adult and child use. Ritonavir, formerly allowed for adult use only, was also approved for adult and child use.
Preliminary results from four American and European studies indicate that these drugs cause dramatic increases in the number of CD4 T-cells and decreases in the amount of virus in the blood. These results are about two to three times more powerful than those seen with the nucleoside drugs. Researchers cautioned that new studies show also that HIV can quickly develop resistance to these new drugs, at least when they are used alone. However, researchers suspect that the resistance can be delayed when the agents are combined with other anti-HIV drugs-for example, the nucleosides.
In fact, the most effective treatment against HIV is now considered to be a combinationof three drugs taken together-two nucleoside RT inhibitors and one protease inhibitor. Although these drug combinations may cause severe side effects (such as diarrhea, abdominal cramps, and anemia), when taken properly they can reduce blood levels of the virus to undetectable levels. Each drug must be taken according to specific guidelines, however, and one missed dose can allow the virus to quickly mutate to a strain that resists the drugs.
These drug combinations can also consist of two nucleoside RT inhibitors and one non-nucleoside RT inhibitor, a new class of anti-HIV drug first recommended for approval by the FDA in June 1996. These drugs work similarly to nucleoside RT inhibitors in that they bind to the HIV reverse transcriptase enzyme. However, they do not compete with other nucleosides for binding sites. The first drug of this type to be developed was nevirapine (Viramune), which was appproved by the FDA in April 1997. A second non-nucleoside RT inhibitor, delavirdine (Rescriptin), is currently available only in test settings. Both drugs are effective only when taken with nucleoside RT inhibitors; they should not be used with protease inhibitors.
 No matter which drug combination is administered, researchers believe that the earlier a patient is treated for HIV, the greater the chance that the treatment will be effective.
The development of antiviral therapies for HIV is complex, and each new approach and drug must be extensively evaluated for safety and effectiveness. The general perception that this evaluation process causes unnecessary delays in providing therapies spurred public demonstrations against the FDA. These demonstrations have resulted in policy changes that make experimental drugs and approaches more readily available to people with AIDS, even before the drugs or approaches are approved. Although early availability of a drug entails the risk that it may be used in people before its toxicity and side effects are fully understood, many people with AIDS are willing to take this risk with the hope that the drug may prove effective.
Effective drug treatments are available to fight many AIDS-associated opportunistic infections, and these treatments have provided clinical benefit and prolonged survival for individuals with AIDS. Recent drug treatments for PCP have dramatically decreased illness and death due to this opportunistic infection. Antifungal drugs such as amphotericin B and fluconazole are effective against AIDS-related fungal infections. The antiherpes drugs ganciclovir and foscarnet are used to treat CMV retinitis and other herpes diseases. Because these therapies require medical supervision and are often needed on an extended basis, a network of community hospices (see Hospital) has been established to provide low-cost outpatient care for individuals with AIDS. Some hospices provide shelter and compassionate support for people living with AIDS.
Gene therapy, an approach that involves altering the genes of the infected person to help prevent the virus from spreading to uninfected cells, might someday be used to treat HIV infection. Gene therapy has been used in clinical trials to inhibit HIV by introducing into cells a new gene that interferes with the viral regulatory proteins. In other trials, gene therapy has been used to introduce a new gene that protects the cells from becoming infected by HIV.
Efforts also are under way to develop an effective immunization that could be either protective, preventing infection if an immunized person is exposed to HIV, or therapeutic, prolonging survival or decreasing immune destruction in people already infected with HIV. The World Health Organization (WHO) is currently sponsoring a large-scale trial of a protective-vaccine candidate in areas of the world where the rate of HIV infection is just beginning to rise dramatically. In 1996 the FDA for the first time gave researchers in the United States permission to inject a vaccine made from simple DNA into healthy, uninfected volunteers. The vaccine in this trial is made from a gene that codes for one of the proteins that form the surface of HIV. Consequently, this DNA vaccine should generate antibodies to the AIDS virus and activate immune cells that kill the virus.
With the discovery in 1996 that HIV must bind to chemokine receptors as well as CD4 molecules, researchers also began to develop laboratory chemokines that might block HIV from attaching to these receptors and casing infection. Individuals who lack CCR5 receptors due to a genetic defect appear to be protected from contracting the disease.
Prevention Efforts
Because there is as yet no successful vaccination against HIV, prevention efforts have focused mainly on educating the public about routes of HIV transmission and about personal measures that reduce the risk of infection. The CDC has established the National AIDS Clearinghouse, a hotline to disseminate educational literature and current statistics on AIDS. Safe-sex campaigns encourage sexual abstinence or monogamy (sexual relations with only one partner) and the use of latex condoms to provide a protective barrier during sexual intercourse (see Birth Control). Needle-exchange programs have been implemented to reduce needle sharing and consequent HIV transmission among IV drug abusers. The U.S. government has set strict guidelines for health-care settings, including use of protective clothing and proper instrument disposal, to decrease the risk of transmission to both the patient and the health care provider. On a national scale, screening of the blood supply has greatly reduced the risk of contracting HIV from blood products. However, with the exception of blood screening, these prevention programs have had only limited success.
Social Issues

Many people consider HIV infection and AIDS to be completely preventable because the routes of HIV transmission are so well known. To completely prevent transmission, however, dramatic changes in sexual behavior and drug dependence would have to occur throughout the world. Furthermore, prevention efforts that promote sexual awareness through open discussion and condom distribution in public schools have been opposed because of the fear that these efforts may encourage sexual activity. Similarly, needle exchange programs have been criticized as promoting drug abuse. Prevention programs that identify HIV-infected individuals and notify their sexual partners, as well as programs that promote HIV testing at the time of marriage or pregnancy, have been criticized for invading personal privacy.
Efforts aimed at public awareness have been propelled by community-based organizations such as Project Inform and Act-Up, which provide current information to HIV-infected individuals and to individuals at risk for infection. Public figures and celebrities who are themselves HIV infected or who have died from AIDS-including American basketball player Magic Johnson, American actor Rock Hudson, American diver Greg Louganis, and American tennis player Arthur Ashe-have personalized the disease of AIDS and thereby helped society come to terms with the enormity of the epidemic. As a memorial to people who have died from AIDS, especially in the early years of the epidemic, friends and families of AIDS victims stitched together a giant quilt in which each panel of the quilt was dedicated to the memory of an individual who died from AIDS. This quilt has traveled on display from community to community to promote AIDS awareness.
The U.S. government has also attempted to assist HIV-infected individuals through legislation and additional community-funding measures. In 1990 HIV-infected people were included in the Americans with Disabilities Act, making discrimination against people with AIDS for jobs, housing, and other social benefits illegal. Additionally, the Ryan White Comprehensive AIDS Resources Emergency Act established a community-funding program designed to assist in the daily lives of people living with AIDS. This congressional act was named in memory of a young man who contracted HIV through blood products and became a public figure for his courage in fighting the disease and community prejudice. The act is still in place, although continued funding for such social programs is threatened by opposition in the U.S. Congress.
The lack of effective vaccines and antiviral drugs for AIDS has spurred speculation that the funding for AIDS research is insufficient. Although the actual amount of government funding for AIDS research is large, most of these funds are used for expensive clinical studies to evaluate new drugs. Many scientists believe that not enough is known about the basic biology of HIV and recommend shifting the emphasis of AIDS research to basic research that could ultimately result in more effective medicines.
Contributed By:
Thomas Murill Folks & Salvatore Thomas Butera[1]

What you have read so far was the original entry in the first ever edition/version of the Microsoft Encarta Encyclopaedia.

Why then did the authors reorganize the text and omit the underlined sentences or sections, which are very vital to the proper understanding of how the retrovirus was "isolated", a terminology they used thrice?

What is ISOLATE and why was it introduced instead of using DISCOVERED or INVENT they were using earlier.

Now, we read what is now in Microsoft ® Encarta ® Encyclopaedia 2004.




I

INTRODUCTION
Acquired Immunodeficiency Syndrome (AIDS), human viral disease that ravages the immune system, undermining the body's ability to defend itself from infection and disease. Caused by the human immunodeficiency virus (HIV), AIDS leaves an infected person vulnerable to opportunistic infections. Such infections are harmless in healthy people, but in those whose immune systems have been greatly weakened, they can prove fatal. Although there is no cure for AIDS, new drugs are available that can prolong the life spans and improve the quality of life of infected people.
Infection with HIV does not necessarily mean that a person has AIDS. Some people who have HIV infection may not develop any of the clinical illnesses that define the full-blown disease of AIDS for ten years or more. Physicians prefer to use the term AIDS for cases where a person has reached the final, life-threatening stage of HIV infection.
II

PREVALENCE
AIDS was first identified in 1981 among homosexual men and intravenous drug users in New York and California. Shortly after its detection in the United States, evidence of AIDS epidemics grew among heterosexual men, women, and children in sub-Saharan Africa. AIDS quickly developed into a worldwide epidemic, affecting virtually every nation. By 2002 an estimated 38.6 million adults and 3.2 million children worldwide were living with HIV infection or AIDS. The World Health Organization (WHO), a specialized agency of the United Nations (UN), estimates that from 1981 to the end of 2002 about 20 million people died as a result of AIDS. About 4.5 million of those who died were children under the age of 15.
A

North America
In the United States about 40,000 new HIV infections occur each year. More than 30 percent of these infections occur in women, and 60 percent occur in ethnic minorities. In 2001 more than 800,000 U.S. residents were infected with HIV, and more than 300,000 people were living with full-blown AIDS. In Canada about 4,200 new HIV infections occur each year. Nearly 25 percent of these infections occur in women. In 2002 about 55,000 Canadians were living with HIV infection and about 18,000 people were living with full-blown AIDS.
The incidence of new cases of HIV infections and AIDS deaths has significantly decreased in Canada and the United States since 1995. This decrease is attributed to the availability of new drug treatments and public health programs that target people most at risk for infection. But while the overall rate of HIV infection seems to be on a downturn, certain populations appear to be at greater risk for the disease. In the United States in 1987, Caucasians accounted for 60 percent of AIDS cases and blacks and Hispanics only 39 percent. But by 2000 the trend had reversed: 26 percent of new cases were diagnosed in Caucasians and 73 percent in blacks and Hispanics. Likewise the number of female AIDS patients in the United States has increased significantly in recent years, from 7 percent of all AIDS cases in 1985 to 30 percent in 2000. In the United States, African American and Hispanic women accounted for 82 percent of AIDS cases among women in 2000.
B

Europe
In western Europe the first cases of AIDS were detected in the early 1980s, and by the late 1990s, at least 30,000 new HIV infections occurred each year. In 2002 about 570,000 western Europeans were HIV positive, and 25 percent of these cases were women. Before the dissolution of the Union of Soviet Socialist Republics (USSR) in 1991, eastern Europe reported few HIV cases. But since 1995, HIV infection has spread rapidly in cities of several eastern European countries, including Ukraine, Belarus, and Moldova. The WHO estimates that the total number of HIV infections in this region may have risen from less than 30,000 in 1995 to about 1 million in 2002.
C

Developing Nations
While cases of AIDS have been reported in every nation of the world, the disease affects some countries more than others. More than 95 percent of all HIV-infected people live in the developing world. In these areas, the disease has sapped the populations of young men and women who form the foundation of the labor force. Most die while in the peak of their reproductive years. Moreover, the epidemic has overwhelmed health-care systems, increased the number of orphans, and caused life expectancy rates to plummet. These problems have reached crisis proportions in some parts of the world already burdened by war, political upheaval, or unrelenting poverty.
Nowhere is this better demonstrated than in sub-Saharan Africa, where the number of AIDS cases far exceeds that of all other geographic regions. Of the estimated 14,000 HIV infections that occur each day worldwide, about half of these infections occur in sub-Saharan Africa. About 70 percent of all people infected with HIV live in this region. In some countries in the southern part of the continent, including Botswana, Lesotho, Swaziland, and Zimbabwe, more than 30 percent of the population has HIV infection or AIDS.
In Asia and the Pacific Islands an estimated 7.2 million people were living with HIV infection by 2002. Health officials fear that as the virus spreads through China and India, the world's two most populous countries, cases of HIV infection in this region may surge up to 25 million cases by the year 2010, dwarfing the problems seen in sub-Saharan Africa.
In 2002 the Chinese government reported that China had about 1 million HIV-positive people in a population of more than 1 billion. However, public health experts are concerned by the fast-rising number of new infections among intravenous drug users who share infected needles. In 2000 HIV prevalence among intravenous drug users ranged from 44 percent to 85 percent in selected communities of drug users in both Yunnan, in southern China, and Xinjiang, in northwestern China. The incidence of HIV infection will likely be exacerbated by the growing sex industry in China. Surveys indicate that as many as 4 million prostitutes work in China. Of these, four out of ten never use a condom to protect themselves or their clients from HIV infection or other sexually transmitted infections. In rural areas of China the incidence of HIV infection is rising because many poverty-stricken people regularly sell their blood. The people who buy the blood use unsterile methods to draw blood, including reusing contaminated needles, which can spread HIV infection.
In Latin America and the Caribbean region nearly 1.7 million people have been diagnosed with HIV infection or AIDS, twice the incidence in the United States and Canada. Brazil, Mexico, Colombia, and Argentina are the Latin American countries with the highest number of cases of HIV infection or AIDS.

III

CAUSE
AIDS is the final stage of a chronic infection with the human immunodeficiency virus. There are two types of this virus: HIV-1, which is the primary cause of AIDS worldwide, and HIV-2, found mostly in West Africa. On its surface, HIV carries a protein structure that recognizes and binds only with a specific structure found on the outer surface of certain cells. HIV attacks any cell that has this binding structure. However, white blood cells of the immune system known as T cells, which orchestrate a wide variety of disease-fighting mechanisms, are especially vulnerable to HIV attack. Particularly vulnerable are certain T cells known as CD4 cells. When HIV infects a CD4 cell, it commandeers the genetic tools within the cell to manufacture new HIV virus. The newly formed HIV virus then leaves the cell, destroying the CD4 cell in the process. No existing medical treatment can completely eradicate HIV from the body once it has integrated into human cells.
The loss of CD4 cells endangers health because these immune cells help other types of immune cells respond to invading organisms. The average healthy person has over 1,000 CD4 cells per microliter of blood. In a person infected with HIV, the virus steadily destroys CD4 cells over a period of years, diminishing the cells' protective ability and weakening the immune system. When the density of CD4 cells drops to 200 cells per microliter of blood, the infected person becomes vulnerable to any of about 26 opportunistic infections and rare cancers, which take advantage of the weakened immune defenses to cause disease.
IV

HOW HIV INFECTION SPREADS
Scientists have identified three ways that HIV infections spread: sexual intercourse with an infected person, contact with contaminated blood, and transmission from an infected mother to her child before or during birth or through breastfeeding.
A

Sex with an Infected Person
HIV transmission occurs most commonly during intimate sexual contact with an infected person, including genital, anal, and oral sex. The virus is present in the infected person's semen or vaginal fluids. During sexual intercourse, the virus gains access to the bloodstream of the uninfected person by passing through openings in the mucous membrane-the protective tissue layer that lines the mouth, vagina, and rectum-and through breaks in the skin of the penis. In the United States and Canada, HIV is most commonly transmitted during sex between homosexual men, but the incidence of HIV transmission between heterosexual men and women has rapidly increased. In most other parts of the world, HIV is most commonly transmitted through heterosexual sex.
B

Contact with Infected Blood
Direct contact with HIV-infected blood occurs when people who use heroin or other injected drugs share hypodermic needles or syringes contaminated with infected blood. Sharing of contaminated needles among intravenous drug users is the primary cause of HIV infection in eastern Europe, particularly in Ukraine, Russia, Belarus, and Moldova. Epidemics of HIV infection among drug users have also emerged in Georgia, Armenia, Azerbaijan, and Kazakhstan in Central Asia.
Less frequently, HIV infection results when health professionals accidentally stick themselves with needles containing HIV-infected blood or expose an open cut to contaminated blood. Some cases of HIV transmission from transfusions of infected blood, blood components, and organ donations were reported in the 1980s. Since 1985 government regulations in the United States and Canada have required that all donated blood and body tissues be screened for the presence of HIV before being used in medical procedures. As a result of these regulations, HIV transmission caused by contaminated blood transfusion or organ donations is rare in North America. However, the problem continues to concern health officials in sub-Saharan Africa. Less than half of the 46 nations in this region have blood-screening policies. By some estimates only 25 percent of blood transfusions are screened for the presence of HIV. WHO hopes to establish blood safety programs in more than 80 percent of sub-Saharan countries by 2003.
C

Mother-to-Child Transmission
HIV can be transmitted from an infected mother to her baby while the baby is still in the woman's uterus or, more commonly, during childbirth. The virus can also be transmitted through the mother's breast milk during breastfeeding. Mother-to-child transmission accounts for 90 percent of all cases of AIDS in children. Mother-to-child transmission is particularly prevalent in Africa, where the number of women infected with HIV is ten times the rate found in other regions. Studies conducted in several cities in southern Africa in 1998 indicate that up to 45 percent of pregnant women in these cities carry HIV.
D

Misperceptions About HIV Transmission
The routes of HIV transmission are well documented by scientists, but health officials continually grapple with the public's unfounded fears concerning the potential for HIV transmission by other means. HIV differs from other infectious viruses in that it dies quickly if exposed to the environment. No evidence has linked HIV transmission to casual contact with an infected person, such as a handshake, hugging, or kissing, or even sharing dishes or bathroom facilities. Studies have been unable to identify HIV transmission from modes common to other infectious diseases, such as an insect bite or inhaling virus-infected droplets from an infected person's sneeze or cough.
V

SYMPTOMS
Without medical intervention, AIDS progresses along a typical course. Within one to three weeks after infection with HIV, most people experience flu-like symptoms, such as fever, sore throat, headache, skin rash, tender lymph nodes, and a vague feeling of discomfort. These symptoms last one to four weeks. During this phase, known as acute retroviral syndrome, HIV reproduces rapidly in the blood. The virus circulates in the blood throughout the body, particularly concentrating in organs of the lymphatic system.
The normal immune defenses against viral infections eventually activate to battle HIV in the body, reducing but not eliminating HIV in the blood. Infected individuals typically enter a prolonged asymptomatic phase, a symptom-free period that can last ten years or more. While persons who have HIV may remain in good health during this period, HIV continues to replicate, progressively destroying the immune system. Often an infected person remains unaware that he or she carries HIV and unknowingly transmits the virus to others during this phase of the infection.
When HIV infection reduces the number of CD4 cells to around 200 per microliter of blood, the infected individual enters an early symptomatic phase that may last a few months to several years. HIV-infected persons in this stage may experience a variety of symptoms that are not life-threatening but may be debilitating. These symptoms include extensive weight loss and fatigue (wasting syndrome), periodic fever, recurring diarrhea, and thrush, a fungal mouth infection. An early symptom of HIV infection in women is a recurring vaginal yeast infection. Unlike earlier stages of the disease, in this early symptomatic phase the symptoms that develop are severe enough to cause people to seek medical treatment. Many may first learn of their infection in this phase.
A

Opportunistic Infections
If CD4 cell levels drop below 200 cells per microliter of blood, the late symptomatic phase develops. This phase is characterized by the appearance of any of 26 opportunistic infections and rare cancers. The onset of these illnesses, sometimes referred to as AIDS-defining complications, is one sign that an HIV-infected person has developed full-blown AIDS. Without medical treatment, this stage may last from several months to years. The cumulative effects of these illnesses usually cause death.
Often the first opportunistic infection to develop is pneumocystis pneumonia, a lung infection caused by the fungus Pneumocystis carinii. This fungus infects most people in childhood, settling harmlessly in the lungs where it is prevented from causing disease by the immune system. But once the immune system becomes weakened, the fungus can block the lungs from delivering sufficient oxygen to the blood. The lack of oxygen leads to severe shortness of breath accompanied by fever and a dry cough.
In addition to pneumocystis pneumonia, people with AIDS often develop other fungal infections. Up to 23 percent of people with AIDS become infected with fungi from the genus Cryptococcus, which cause meningitis, inflammation of the membranes that surround the brain. Infection by the fungus Histoplasma capsulatum affects up to 10 percent of people with AIDS, causing general weight loss, fever, and respiratory complications.
Tuberculosis, a severe lung infection caused by the bacterium Mycobacterium tuberculosis, typically becomes more severe in AIDS patients than in those with a healthy immune system. Between the 1950s and the late 1980s, tuberculosis was practically eradicated in North America. In the early 1990s, doctors became alarmed when incidence of the disease dramatically escalated. This resurgence has been attributed to the increased susceptibility to tuberculosis of people infected with HIV. Infection by the bacterium Mycobacterium avium can cause fever, anemia, and diarrhea. Other bacterial infections of the gastrointestinal tract contribute to wasting syndrome.
Opportunistic infections caused by viruses, especially members of the herpesvirus family, are common in people with AIDS. One of the herpesviruses, cytomegalovirus (CMV), infects the retina of the eye and can result in blindness. Another herpesvirus, Epstein-Barr virus (EBV), may cause certain types of blood cancers. Infections with herpes simplex virus (HSV) types 1 or 2 may result in sores around the mouth, genital area, or anus.
Many people with AIDS develop cancers. The destruction of CD4 cells impairs the immune functions that halt the development of cancer. Kaposi's sarcoma is a cancer of blood vessels caused by a herpesvirus. This cancer produces purple lesions on the skin, which can spread to internal organs and cause death. B cell lymphoma affects certain cells of the lymphatic system that fight infection and perform other vital functions. Cervical cancer is more common in HIV-infected women than in women free from infection.
A variety of neurological disorders are common in the later stage of AIDS. Collectively called HIV-associated dementia, they develop when HIV or another microbial organism infects the brain. The infection produces degeneration of intellectual processes such as memory and, sometimes, problems with movement and coordination.
B

Symptoms in Children
HIV infection in children progresses more rapidly than in adults, most likely because the immune systems in children have not yet built up immunity to many infectious agents. The disease is particularly aggressive in infants-more than half of infants born with an HIV infection die before age two. Once a child is infected, the child's undeveloped immune system cannot prevent the virus from multiplying quickly in the blood. This extensive virus burden speeds the progression of the disease. In contrast, when adults become infected with HIV, their immune system generally fights the infection. Therefore, HIV levels in adults remain lower for an extended period, delaying the progression of the disease.
Children develop many of the opportunistic infections that befall adults but also exhibit symptoms not observed in older patients. Among infants and children, HIV infection produces wasting syndrome and slows growth (generally referred to as failure to thrive). HIV typically infects a child's brain early in the course of the disease, impairing intellectual development and coordination skills. While HIV can infect the brains of adults, it usually does so toward the later stages of the disease and produces different symptoms.
Children show a susceptibility to more bacterial and viral infections than adults. More than 20 percent of HIV-infected children develop serious, recurring bacterial infections, including meningitis and pneumonia. Some children suffer from repeated bouts of viral infections, such as chicken pox. Healthy children generally develop immunity to these viral illnesses after an initial infection.
VI

DETECTING AND MONITORING HIV INFECTION
Since HIV was first identified as the cause of AIDS in 1983, a variety of tests have been developed that help diagnose HIV infection as well as determine how far the infection has progressed. Other tests can be used to screen donated blood, blood products, and body organs for the presence of HIV.
Doctors determine if HIV is present in the body by identifying HIV antibodies, specialized proteins created by the immune system to destroy HIV. The presence of the antibodies indicates HIV infection because these antibodies form in the body only when HIV is present. HIV antibodies form anywhere from five weeks to three months after HIV infection occurs, depending upon the individual's immune system. The antibodies are produced continually throughout the course of the infection.
The standard test to detect HIV antibodies in the blood is the enzyme-linked immunosorbent assay (ELISA). In this test, a blood sample is mixed with proteins from HIV. If the blood contains HIV antibodies, they attach to the HIV proteins, producing a telltale color change in the mixture. This test is highly reliable when performed two to three months after infection with HIV. The test is less reliable when used in the very early stage of HIV infection, before detectable levels of antibodies have had a chance to form. Doctors routinely confirm a positive result from an ELISA test by using the Western Blot test, which can detect lower levels of HIV antibodies. In this test a blood sample is applied to a paper strip containing HIV proteins. If HIV antibodies are present in the blood, they bind to the HIV proteins, producing a color change on the paper. The combination of the ELISA and the Western Blot test is more than 99.9 percent accurate in detecting HIV infection within 12 weeks following exposure.
Once tests confirm an HIV infection, doctors monitor the health of the infected person's immune system by periodically measuring CD4 cell counts in the blood. The progressive loss of CD4 cells corresponds to a worsening of the disease as the immune system becomes increasingly impaired. Doctors also measure the viral load-the amount of the virus in the blood-using polymerase chain reaction (PCR) technology. PCR tests measure the level of viral ribonucleic acid (RNA), a type of nucleic acid, in blood to determine the rate of HIV growth in an infected person. Knowing the viral load helps doctors estimate an infected person's survival time. For example, studies show that without treatment, the average survival time for people with an HIV viral load greater than 30,000 per microliter of blood is 4.4 years, while those with a viral load below 10,000 per microliter of blood live for an average of ten years.
A modified ELISA test that detects p24 antigen, a protein produced by HIV, can determine if specific drug treatments are having a positive effect on a patient. Blood banks, plasma centers, clinical laboratories, private clinics, and public health departments also use this p24 antigen test to screen for the presence of HIV in blood, blood components, and organs before they are used in medical procedures.

VII

DIAGNOSING AIDS
Physicians prefer to differentiate between people who have HIV infection and those who have AIDS. The Centers for Disease Control and Prevention (CDC), based in Atlanta, Georgia, recommends that physicians reserve the diagnosis of AIDS for HIV-infected individuals whose CD4 count falls below 200 cells per microliter of blood. A diagnosis of AIDS can also be made without confirmation of CD4 levels if someone who has no other reason for immune system damage develops an opportunistic disease.
VIII

TREATMENT
While no medical treatment cures AIDS, in the relatively short time since the disease was first recognized, new methods to treat the disease have developed rapidly. Health-care professionals focus on three areas of therapy for people living with HIV infection or AIDS: antiretroviral therapy using drugs that suppress HIV replication; medications and other treatments that fight the opportunistic infections and cancers that commonly accompany HIV infection; and support mechanisms that help people deal with the emotional repercussions as well as the practical considerations of living with a disabling, potentially fatal disease.
A

Antiretroviral Therapies
Understanding the specific steps in the HIV replication cycle is critical in order for scientists to develop drugs that attack vulnerable stages within the cycle. HIV belongs to a unique group of viruses known as retroviruses, so named because these viruses reverse the usual flow of genetic information within an infected cell. Most viruses store their genetic material in deoxyribonucleic acid (DNA), the double-helix structure that makes up genes. When a virus infects a cell, the viral DNA forms the template for the creation of messenger RNA, a type of ribonucleic acid. This messenger RNA directs the formation of specific proteins, and these proteins, in turn, build new virus particles (see Genetics). In HIV, however, genetic material is stored in two single-stranded RNA molecules. When HIV infects a cell, an enzyme called reverse transcriptase copies the genetic instructions in the virus's RNA and moves it into the DNA. This movement of genetic information from RNA to DNA is the opposite of that which occurs in most cells during protein synthesis.
Another HIV enzyme, called integrase, helps the newly formed viral DNA to become part of the structure of the infected cell's DNA. The viral DNA then forces the infected cell to manufacture HIV particles. A third HIV enzyme, called protease, packages these HIV particles into a complete and functional HIV virus. Over the last decade researchers have created a variety of drugs that block the action of some of the enzymes used in HIV replication. The three main classes of drugs used against HIV are nucleoside analogues, non-nucleoside reverse transcriptase inhibitors, and protease inhibitors.
Nucleoside analogues impede the action of reverse transcriptase, the HIV enzyme that converts the virus's genetic material into DNA. During this conversion process, these drugs incorporate themselves into the structure of the viral DNA, rendering the DNA useless and preventing it from instructing the infected cell to make additional HIV. The nucleoside analogue known as azidothymidine (AZT), which became available in 1987, was the first drug approved by the United States Food and Drug Administration (FDA) to treat AIDS. AZT slows HIV growth in the body, permitting an increase in the number of CD4 cells, which boosts the immune system. AZT also prevents transmission of HIV from an infected mother to her newborn. Since the introduction of AZT, additional nucleoside analogues have been developed, including didanosine (sold under the trade name Videx), zalcitabine (HIVID), stavudine (Zerit), lamivudine (Epivir), and abacavir (Ziagen). These drugs are not particularly powerful when used alone, and often their benefits last for only 6 to 12 months. But when nucleoside analogues are used in combination with each other, they provide longer-lasting and more effective results.
Non-nucleoside reverse transcriptase inhibitors (NNRTIs), introduced in 1996, use a different mechanism to block reverse transcriptase. These drugs bind directly to reverse transcriptase, preventing the enzyme from converting RNA to DNA. Three NNRTIs are available: nevirapine (Viramune), delavirdine (Rescriptor), and efavirenz (Sustiva). NNRTIs work best when used in combination with nucleoside analogues.
The third group of antiviral drugs, called protease inhibitors, cripples protease, the enzyme vital to the formation of new HIV. When these drugs block protease, defective HIV forms that is unable to infect new cells. Protease inhibitors are more powerful than nucleosides and NNRTIs, producing dramatic decreases in HIV levels in the blood. This reduced viral load, in turn, enables CD4 cell levels to skyrocket. The first protease inhibitor, saquinavir (Invirase), was approved in 1995. Since then other protease inhibitors have been approved, including ritonavir (Norvir), indinavir (Crixivan), nelfinavir (Viracept), and amprenavir (Agenerase).
A1

Drug Resistance
Clinical studies of treatment with antiretroviral drugs immediately showed that their benefits are short-lived when a single drug is used alone. This short-term effectiveness results when HIV mutates, or changes its genetic structure, becoming resistant to the drug. The genetic material in HIV provides instructions for the manufacture of critical enzymes needed to replicate the virus. Scientists design current antiretroviral drugs to impede the activity of these enzymes. If the virus mutates, the structure of the virus's enzymes changes. Drugs no longer work against the enzymes, making the drugs ineffective against viral infection.
Genes mutate during the course of viral replication, so the best way to prevent mutation is to halt replication. Studies have shown that the most effective treatment to halt HIV replication employs a combination of three drugs taken together-for instance, a combination of two nucleoside analogues with a protease inhibitor. This regimen, called triple therapy, maximizes drug potency while reducing the chance for drug resistance. The combination of three drugs is often referred to as an AIDS cocktail. In HIV-infected patients who have undergone triple therapy, the viral loads reduced significantly, sometimes to undetectable levels. Their CD4 cell count gradually increased, and they sustained good health with no complications. With this treatment, some patients who were near death were able to return to work and normal physical activity. Triple therapy was introduced in the United States in 1996. That year AIDS deaths in the United States decreased 26 percent, the first decrease since the beginning of the epidemic. In 1997 U.S. AIDS deaths decreased by 56 percent from the year before.
Despite phenomenal success, triple therapy has some drawbacks. This multidrug therapy is quite complicated, requiring patients to take anywhere from 5 to 20 pills a day on a specific schedule. Some drugs must be taken with food, while others cannot be taken at the same time as certain other pills. Even the most organized people find it difficult to take pills correctly. Yet, just one or two lapses in treatment may cause the virus to develop resistance to the drug regimen.
Many people also find it difficult to deal with the unpleasant side effects produced by antiretroviral drugs. Common side effects include nausea, diarrhea, headache, fatigue, abdominal pain, kidney stones, anemia, and tingling or numbness in the hands and feet. Some patients may develop diabetes mellitus, while other patients develop collections of fat deposits in the abdomen or back, causing a noticeable change in body configuration. Some antiretroviral drugs produce an increase in blood fat levels, placing a patient at risk for heart attack or stroke. Some patients suffer more misery from the drug treatment than they do from the illnesses produced by HIV infection.
Perhaps the greatest drawback to triple therapy is its cost, which ranges from $10,000 to $12,000 a year. This high cost is well beyond the means of people with low incomes or those with limited health-care insurance. As a result, the most effective therapies currently available remain beyond the reach of the majority of HIV-infected people worldwide.
To decrease the toxic effects of drugs and to defer costly therapy, in 2001 United States federal health officials recommended delaying drug treatment for HIV infection in people showing no symptoms and who have been infected with HIV for more than six months. The new guidelines call for delaying treatment until an infected person's CD4 cells fall below 350 cells per microliter of blood or the HIV viral load exceeds 30,000 per microliter of blood. Evidence suggests that delaying treatment poses no harm to infected people and, in fact, benefits them by deferring the toxic side effects of the drugs.
A2

Postexposure Prevention
Studies show that under certain circumstances, administering antiretroviral drugs within 24 hours (preferably within one to two hours) after exposure to HIV can protect a person from becoming infected with the virus. Although the effectiveness of postexposure antiretroviral therapy following sexual exposure to HIV remains uncertain, the CDC recommends that health-care personnel exposed to HIV infection from a needle stick or other accident take antiretroviral drugs.

A3

Development of New Drugs
Scientists continue to develop more powerful HIV treatments that have fewer side effects and fewer resistance problems. Some drugs under investigation block the HIV enzyme integrase from inserting viral DNA into the infected cell. Other drugs prevent HIV from binding with a CD4 cell in the first place, thereby barring HIV entry into cells.
Some scientists focus on ways to fortify the immune system. A biological molecule called interleukin-2 shows promise in boosting the immune system's arsenal of infection-fighting cells. Interleukin-2 stimulates the production of CD4 cells. If enough CD4 cells can be created, they may trigger other immune cell responses that can overpower HIV infection.
In other research, doctors hope to bolster the immune system with a vaccine. Most vaccines available today, including those that prevent measles or poliomyelitis, work by helping the body to create antibodies. Such vaccines mark specific infectious agents, such as the measles and polio viruses, for destruction. But many experts believe that an effective HIV vaccine will need to do more than just stimulate anti-HIV antibodies. Studies are underway to develop vaccines that also elevate the production of T cells in the immune system. Scientists hope that this dual approach will prime the immune system to attack HIV as soon as it appears in the body, perhaps containing the virus before it spreads through the body in a way that natural immune defenses cannot. The genetic variability of HIV frustrates efforts to develop a vaccine: A vaccine effective against one type of HIV may not work on a virus that has undergone genetic mutation.
B

Treatment of Opportunistic Infections
In addition to antiretroviral therapy to combat HIV infection, effective drug treatments are available to fight many of the medical complications that result from HIV infection. Doctors try to prevent infections before they begin to avoid taxing a patient's weakened immune system unnecessarily. A doctor instructs an HIV-infected person on ways to avoid exposure to infectious agents that produce opportunistic infections common in people with a weakened immune system. Doctors usually prescribe more than one drug to forestall infections. For example, for those who have a history of pneumocystic pneumonia and a CD4 cell count of less than 200 cells per microliter, doctors may prescribe the antibiotics sulfamethoxazole and trimethoprim to prevent further bouts of pneumonia. Patients suffering from recurring thrush may be given the antifungal drug fluconazole for prolonged periods. For people with CD4 cell counts of less than 100 cells per microliter, doctors may prescribe clarithromycin or azithromycin to prevent Mycobacterium avium infections.
C

Support Mechanisms
A person diagnosed with HIV infection faces many challenges, including choosing the best course of treatment, paying for health care, and providing for the needs of children in the family while ill. In addition to these practical considerations, people with HIV infection must cope with the emotional toll associated with the diagnosis of a potentially fatal illness. The social stigma that continues to surround a diagnosis of AIDS because of the disease's prevalence among gay men or drug users causes many people to avoid telling family or friends about their illness. People with AIDS often feel incredibly lonely as they try to cope with a devastating illness on their own. Loneliness, anxiety, fear, anger, and other emotions often require as much attention as the medical illnesses common to HIV infection.
Since the AIDS epidemic began in the United States in 1981, grassroots organizations have been created to meet the medical and emotional needs of people who have AIDS and also to protect their civil rights. The Gay Men's Health Crisis, founded in 1982, was the first nonprofit organization to provide medical, education, and advocacy services for people with AIDS. The Los Angeles Shanti Group was established in 1983 to provide emotional support and medical guidance to people with AIDS and other life-threatening illnesses. Activist organizations such as the AIDS Coalition to Unleash Power (ACT UP), founded in 1986, have been created to initiate faster change in public policies and to speed up the course of AIDS clinical research. American Foundation for AIDS Research (AMFAR), created in 1985, is the nation's leading nonprofit organization dedicated to the support of AIDS research and the advocacy of fair and compassionate AIDS-related public policies. In Canada, the AIDS Committee of Toronto (ACT) was established in 1983 by community activists intent on fighting for the civil rights of people infected with HIV. As the AIDS epidemic grew, ACT expanded its mission to help people disabled by the disease and to spread health information to halt the spread of the disease. AIDS Vancouver (AV), also established in 1983, became the principal education, prevention, and support service organization for that city.
Counseling centers and churches provide individual or group counseling to help people with HIV infection or AIDS share their feelings, problems, and coping mechanisms with others. Family counseling can address the emotions of other family members who are disturbed by the diagnosis of HIV infection in another family member. Grief counseling also helps people who have lost friends or family members to AIDS.
In the United States and Canada, government-funded and privately funded organizations help people cope with disease. For instance, local, city-funded clinics provide AIDS testing as well as counseling to prepare people for a test result that indicates HIV infection. Health experts at clinics explain the medical progression of the illness, arrange medical appointments with health-care specialists, and help people choose appropriate treatment options. State-appointed social workers and community nonprofit organizations help people find federally funded programs that offset the high cost of medical care and child care.
The United States Congress has passed legislation to help HIV-infected individuals. In 1990 the Americans with Disabilities Act (ADA) was enacted, protecting people with disabling diseases, including AIDS, from discrimination in activities such as applying for jobs or buying a house. The Ryan White Comprehensive AIDS Resources Emergency Act was established in 1990 and reauthorized in 1996. This program provides medical and dental care, counseling, transportation, and home and hospice care for low-income or uninsured people living with AIDS. The AIDS Drug Assistance Program (ADAP) is funded in large part by this act and administered by all 50 states. It pays for costly AIDS medications for people who do not have private insurance and who are not poor enough to be eligible for Medicaid.
IX

PREVENTION
With a vaccine for AIDS years away and no cure on the horizon, experts believe that the most effective treatment for AIDS is to prevent the occurrence of HIV infection. Health officials focus public education programs on altering risky behaviors linked to HIV transmission, particularly unsafe sexual practices and needle-sharing by intravenous drug users. Safe-sex campaigns sponsored by health clinics, social centers, schools, and churches encourage sexual abstinence or monogamy (sexual relations with only one partner). Education programs instruct about the proper way to use condoms to provide a protective barrier against transmission of HIV during sexual intercourse. Needle-exchange programs, which provide clean needles to drug users, enable intravenous drug abusers to avoid sharing HIV-contaminated needles. Needle-exchange programs have been widely criticized because they seem to condone illicit drug use. However, numerous U.S. government-funded studies have indicated that such programs reduce HIV transmission without promoting greater drug use. To reduce the accidental transmission of HIV during medical procedures, both the United States and Canada have established strict guidelines for health-care settings, including the use of protective clothing and proper instrument disposal.
In the United States, the effectiveness of public education programs that target people at risk for HIV infection was well demonstrated in the gay community of San Francisco, California, in the 1980s. In 1982 and 1983, 6,000 to 8,000 people in San Francisco became infected with HIV. The gay community rallied to promote condom use and advocate monogamy through extensive education programs and public health advertisements geared for gay men. These public education programs were credited with reducing the number of gay men in San Francisco who became HIV infected. By 1993 the number of new infections declined to 1,000, and by 1999, fewer than 500 people were infected each year.
Public education about AIDS has also proven effective in other countries. Uganda was one of the first African countries to report cases of HIV infection. The first cases of AIDS were reported there in 1982, and by the late 1980s Uganda had one of the highest rates of HIV infection in the world. The Ugandan government was one of the first countries to set up a partnership with WHO to create a national AIDS control program called the AIDS Information Centre (AIC). The AIC has established extensive education programs promoting condom use and other methods to prevent HIV from spreading further. The program has also worked with community organizations to change social behaviors that increase the risk of HIV infection. The AIC promotes its message using innovative drama, song, and dance programs, a particularly effective communication method for African communities. AIC established confidential HIV testing services that provide same-day results and community counseling programs. As a result of Uganda's quick response to the AIDS epidemic, the number of HIV infected people in that country has declined significantly since 1993, during a time when most other African nations faced a frightening increase in the incidence of HIV infection.
Public health officials have learned that education programs that teach and reinforce safe behaviors through a series of meetings are more effective than one-time exposure to public-health information provided in a class lecture, magazine article, advertisement, or pamphlet. Education programs tailored to reflect specific ethnic and cultural preferences prove even more effective. For example, the Canadian Aboriginal AIDS Network creates HIV education programs that fight the common misperception among the indigenous peoples of Canada that AIDS is primarily a disease of white, affluent people. Among indigenous communities, the network promotes programs that use colloquial language to increase awareness about safe sex practices and needle use.
X

HISTORY
In the short time since the first cases of the AIDS epidemic were reported in 1981, scientists have identified the viral cause of the illness, the basic modes of transmission, accurate tests for the presence of infection, and effective drugs that slow or halt the progression of the disease. During that same period, governments and grassroots organizations around the world were spurred into action to meet the growing need for AIDS education, counseling, patients' rights, and clinical research. Despite these advances, critics observe that many governments were slow to respond to the crisis. For example, United States president Ronald Reagan did not discuss AIDS in public until 1987, more than six years after the start of the AIDS epidemic. By that time, 41,000 Americans had already died from the disease. AIDS advocates believe that the lack of federal support for AIDS research in these early years delayed the development of an effective vaccine or a cure for the disease.
A

Origin of the Virus
Using computer technology to study the structure of HIV, scientists have determined that HIV originated around 1930 in rural areas of Central Africa, where the virus may have been present for many years in isolated communities. The virus probably did not spread because members of these rural communities had limited contact with people from other areas. But in the 1960s and 1970s, political upheaval, wars, drought, and famine forced many people from these rural areas to migrate to cities to find jobs. During this time, the incidence of sexually transmitted infections, including HIV infection, accelerated and quickly spread throughout Africa. As world travel became more prevalent, HIV infection developed into a worldwide epidemic. Studies of stored blood from the United States suggest that HIV infection was well established there by 1978.
In 1970, at about the same time that the HIV epidemic was taking hold in Africa, American molecular biologist David Baltimore and American virologist Howard Temin independently discovered the enzyme reverse transcriptase, which could be used to identify retroviruses. Over the next ten years, many retroviruses were identified in animals. But not until 1980, shortly before the first AIDS cases were recognized in the United States, did American virologist Robert Gallo identify the first human retroviruses, HTLV-I and HTLV-II (HTLV stands for human T cell lymphotropic virus).
Other studies demonstrated that these human retroviruses were more closely related to a retrovirus found in African chimpanzees than to each other. This discovery suggests that the human retroviruses may have evolved from retroviruses that originally infected chimpanzees. The chimpanzee retrovirus likely infected people and underwent mutations to form the human retrovirus. In 1999 scientists confirmed that HIV spread from chimpanzees to humans on at least three separate occasions in Central Africa, probably beginning in the 1940s or 1950s.
B

Disease First Identified
Beginning in June 1981 the CDC published reports on clusters of gay men in New York and California who had been diagnosed with pneumocystic pneumonia or Kaposi's sarcoma. These two rare illnesses had previously been observed only in people whose immune systems had been damaged by drugs or disease. These reports triggered concern that a disease of the immune system was spreading quickly in the homosexual community. Initially called gay-related immunodeficiency disease (GRID), the new illness soon was identified in population groups outside the gay community, including users of intravenous drugs, recipients of blood transfusions, and heterosexual partners of infected people. In 1982 the name for the new illness was changed to acquired immunodeficiency syndrome, or AIDS.
While the disease was making headlines for the speed with which it was spreading around the world, the cause of AIDS remained unidentified. Fear of AIDS and ignorance of its causes resulted in some outlandish theories. Some thought the disease was God's punishment for behaviors that they considered immoral. These early theories created a social stigma surrounding the disease that still lingers.
Scientists quickly identified the primary modes of transmission-sexual contact with an infected person, contact with infected blood products, and mother-to-child transmission. From these modes of transmission it was clear that the new illness was spread in a specific manner that matched the profile of a viral infection. In 1983 French cancer specialist Luc Montagnier and his colleagues isolated what appeared to be a new human retrovirus from AIDS patients. They named it lymphadenopathy virus (LAV). Eight months later Gallo and his colleagues isolated the same virus in AIDS patients, naming the virus HTLV-III. Eventually, scientists agreed to call the infectious agent human immunodeficiency virus (HIV). In 1985 a new AIDS-causing virus was discovered in West Africa. Named HIV-2, the new virus is closely related to the first HIV, but it appears to be less harmful to cells of the immune system and reproduces more slowly than HIV-1.
Research leading to the development of the ELISA test was conducted simultaneously by teams led by Gallo in the United States and Montagnier in France. In 1985 the ELISA test to identify HIV in blood became available, followed by the development of the Western Blot test. These tests were first employed to screen blood for the presence of HIV before the blood was used in medical procedures. The tests were later used to identify HIV-infected people, many of whom did not know they were infected. These diagnostic tests also helped scientists study the course of HIV infection in populations.
C

Defining the Illness
The CDC presented its first definition of AIDS in 1982. The CDC recommended that physicians diagnose AIDS if a person has an illness known to be caused by immune deficiency, as long as there is no known cause for this immune deficiency (people who undergo radiation therapy or who take certain drugs may impair their immune systems). As more information became known about the course of HIV infection and the nature of the virus itself, this definition of AIDS was revised repeatedly to expand the list of illnesses considered diagnostic indicators of the disease. Early definitions were based on the opportunistic infections commonly found in HIV-infected men. As a result, many women who did not have symptoms covered in the official AIDS definition were denied disability benefits and AIDS-related drug therapies.
The current definition of AIDS was created in 1993 and includes 26 opportunistic infections and cancers, known as diagnostic indicators, that affect both men and women. The definition also emphasizes the importance of the level of CD4 cells in the blood. Today doctors make the diagnosis of AIDS in anyone with a CD4 count below 200 cells per microliter of blood, regardless of the associated illnesses they may have.
XI

SOCIAL PERSPECTIVES
Although new and effective AIDS drugs have brought hope to many HIV-infected persons, a number of social and ethical dilemmas still confront researchers and public-health officials. The latest combination drug therapies are far too expensive for infected persons in the developing world-particularly in sub-Saharan Africa, where the majority of AIDS deaths have occurred. In these regions, where the incidence of HIV infection continues to soar, the lack of access to drugs can be catastrophic. In 1998, responding to an international outcry, several pharmaceutical firms announced that they would slash the price of AIDS drugs in developing nations by as much as 75 percent. However, some countries argued that drug firms had failed to deliver on their promises of less expensive drugs. In South Africa government officials developed legislation that would enable the country to override the patent rights of drug firms by importing cheaper generic medicines made in India and Thailand to treat HIV infection. In 1998, 39 pharmaceutical companies sued the South African government on the grounds that the legislation violated international trade agreements. Pharmaceutical companies eventually dropped their legal efforts in April 2001, conceding that South Africa's legislation did comply with international trading laws. The end of the legal battle was expected to pave the way for other developing countries to gain access to more affordable AIDS drugs.

A

Testing AIDS Drugs and Vaccines
AIDS research in the developing world has raised ethical questions pertaining to the clinical testing of new therapies and potential vaccines. For example, controversy erupted over 1997 clinical trials that tested a shorter course of AZT therapy in HIV-infected pregnant women in developing countries. Earlier studies had shown that administering AZT to pregnant women for up to six months prior to birth could cut mother-to-child transmission of HIV by up to two-thirds. The treatment's $800 cost, however, made it too expensive for patients in developing nations.
The controversial 1997 clinical trials, which were conducted in Thailand and other regions in Asia and Africa, tested a shorter course of AZT treatment, costing only $50. Some pregnant women received AZT, while others received a placebo-a medically inactive substance often used in drug trials to help scientists determine the effectiveness of the drug under study. Ultimately the shorter course of AZT treatment proved to be successful and is now standard practice in a growing number of developing nations. However, at the time of the trials, critics charged that using a placebo on HIV-infected pregnant women-when AZT had already been shown to prevent mother-to-child transmission-was unethical and needlessly placed babies at fatal risk. Defenders of the studies countered that a placebo was necessary to accurately gauge the effectiveness of the AZT short-course treatment. Some critics speculated whether such a trial, while apparently acceptable in the developing nations of Asia and Africa, would ever have been viewed as ethical, or even permissible, in a developed nation like the United States.
Similar ethical questions surround the testing of AIDS vaccines in developing nations. Vaccines typically use weakened or killed HIV to spark antibody production. In some vaccines, these weakened or killed viruses have the potential to cause infection and disease. Critics questioned whether it is ethical to place all the risk on test subjects in developing regions such as sub-Saharan Africa, where a person infected by a vaccine would have little or no access to medical care. At the same time, with AIDS causing up to 5,500 deaths a day in Africa, others feel that developing nations must pursue any medical avenue for stemming the epidemic and protecting people from the virus.
B

Economic Burden
For the struggling economies of some developing nations, AIDS has brought yet another burden: AIDS tends to kill young adults in the prime of their lives-the primary breadwinners and caregivers in families. According to figures released by the United Nations in 1999, AIDS has shortened the life expectancy in some African nations by an average of seven years. In Zimbabwe, life expectancy has dropped from 61 years in 1993 to 49 in 1999. The next few decades may see it fall as low as 41 years. Upwards of 11 million children have been orphaned by the AIDS epidemic. Those children who survive face a lack of income, a higher risk of malnutrition and disease, and the breakdown of family structure.
In Africa, the disease has had a heavy impact on urban professionals-educated, skilled workers who play a critical role in the labor force of industries such as agriculture, education, transportation, and government. The decline in the skilled workforce has already damaged economic growth in Africa, and economists warn of disastrous consequences in the future.
C

Social Stigma and Discrimination
From the early days of the identification of AIDS, the disease has been powerfully linked to behaviors that are illegal (such as illicit drug use) or are considered immoral by many people (such as promiscuity and homosexuality). Consequently, a diagnosis of AIDS was a mark of disgrace, although medical research revealed that the disease follows well-defined modes of transmission that can affect any person. As the extent of the epidemic unfolded, misinformation about AIDS and how it is transmitted triggered widespread fear of contracting the disease. Some communities responded with hysteria that resulted in violence. In the United States in 1987, a Florida family with three HIV-positive sons who had become infected from blood transfusions were driven from their home when it was torched by an arsonist. In other communities, parents protested when HIV-infected children attended school. In many areas of the world, women in particular may face consequences if their HIV status is discovered. Reports indicate that many HIV-infected women are subject to domestic violence at the hands of their husbands-even if the husbands themselves are the source of infection. As a result, some women in developing nations fear being tested for HIV infection and cut themselves off from medical care and counseling.
In addition to social stigma, HIV-infected persons must grapple with more immediate concerns-a daily struggle for basic medical care and other basic rights in the face of discrimination and fear because of their HIV status. In China, for example, the number of HIV-positive individuals is a comparatively small problem so far. Yet nurses and other medical personnel who fear infection commonly refuse to perform procedures on HIV-infected people. This sort of discrimination against HIV-infected individuals has long been a problem in the United States. In 1998 the United States Supreme Court heard the case of Sidney Abbott, a young woman in Maine who sued dentist Randon Bragdon after he refused to treat her when he learned of her HIV-positive status. Basing its ruling on the Americans with Disabilities Act, the Supreme Court ruled in Bragdon v. Abbott that the woman's HIV infection constituted a disability, even though she suffered from no disease symptoms. AIDS advocates expect this decision to protect the rights of many people with AIDS in the United States.
Some developing nations, such as Uganda, have met the AIDS crisis head-on, attempting to educate citizens and change high-risk behaviors in the population. However, other nations have been slow to even acknowledge the disease. In India, for example, the nation's prime minister did not speak publicly about the dangers posed by the epidemic until 1999.
In developed nations, some of the stigma attached to a diagnosis of AIDS has lessened in recent years, in part due to the admissions by public figures and celebrities, especially in the United States, that they were HIV infected. The deaths from AIDS of actor Rock Hudson and tennis player Arthur Ashe, and the AIDS advocacy roles of basketball player Magic Johnson and Olympic diver Greg Louganis have personalized the disease and helped society come to terms with the enormity of the epidemic.
To some scientists, the AIDS epidemic signals a troubling trend in humanity's future. Along with other deadly microbial threats of recent years-most notably Ebola virus, which has caused sporadic epidemics in Africa, and hantavirus, which broke out in the American Southwest in the early 1990s-AIDS is viewed by some as yet another in a series of emerging diseases that demonstrate how vulnerable humans are to newly encountered microbes. With population and land development increasing, humans have encroached farther into rain forests and other formerly wild areas, unleashing previously unknown disease agents. Meanwhile, global travel has become faster, more convenient, and more accessible to many people. Some scientists are worried by these trends, fearing the potential for an as-yet-unknown pathogen to arise and spread quickly and lethally around the globe.
The social, ethical, and economic effects of the AIDS epidemic are still being played out, and no one is entirely certain what the consequences will be. Despite the many grim facts of the AIDS epidemic, however, humanity is armed with proven, effective weapons against the disease: knowledge, education, prevention, and the ever-growing store of information about the virus's actions.
Contributed By: John G. Bartlett
Microsoft ® Encarta ® Encyclopedia 2004. © 1993-2003 Microsoft Corporation. All rights reserved.


Let us seek from the same encyclopaedia the true meanings of the words isolate, discover and invent.


ISOLATE:
Basque Language
Basque Language, language spoken by the Basques, the people inhabiting north central Spain and the department of Pyrénées-Atlantiques in southwestern France. The Basque name for their language is Euskara. The language has a number of dialects, of which the chief are Guipúzcoan, Biscayan, and Navarrese in Spain and Labourdin and Navarrais in France. In terms of word formation, Basque is classified as an agglutinative language. The number of sounds varies according to the dialect; most dialects have five vowels. Basque words are accented as a rule on the last syllable; in most instances the latter ends with a vowel or s, r, l, n, or t. Although the rules governing the use of nouns and pronouns are fairly simple, the conjugation of Basque verbs is extremely complicated. The transitive form of a verb may have as many as 24 variations. The Basque vocabulary contains no original words for abstract concepts and no words for tools or utensils brought into use in modern times. To designate such objects the Basques employ a Latin, French, or Spanish word with a Basque ending. For example, the word fork (French fourchette) becomes fourchetta in Basque. The Roman alphabet is used in the written language, which is based on French or Spanish orthography and is phonetic.
Linguists have tried for a long time to trace the origin of the language. Most linguists consider it to be an isolate, or language with no known relatives; attempts have been made to show an affinity between Basque and certain other languages such as Iberian (an ancient language of eastern Spain), Ligurian (an ancient language of northwestern Italy), or the Caucasian languages of the Caucasus region of Georgia and Russia, but no conclusive proof exists for these proposals. Basque was almost certainly spoken in ancient Aquitania, the region of Gascony, France.
Although Basque is one of the oldest historically documented languages, Basque literature is meager. The first Basque book on record was printed in 1545 and is a collection of religious and love poems entitled (in Latin) Linguae Vasconum Primitivae. The most important Basque work is the translation of the New Testament that appeared in 1571. Next in importance is a collection of religious and military chronicles published in the 17th century. Following the Spanish Civil War (1936-39), the regime of Francisco Franco in Spain suppressed the use of Basque. Many present-day Basques are attempting to revive the language.
Contributed By:
James F. Shearer
Microsoft ® Encarta ® Encyclopedia 2004. © 1993-2003 Microsoft Corporation. All rights reserved.


B

Disease First Identified
Beginning in June 1981 the CDC published reports on clusters of gay men in New York and California who had been diagnosed with pneumocystic pneumonia or Kaposi's sarcoma. These two rare illnesses had previously been observed only in people whose immune systems had been damaged by drugs or disease. These reports triggered concern that a disease of the immune system was spreading quickly in the homosexual community. Initially called gay-related immunodeficiency disease (GRID), the new illness soon was identified in population groups outside the gay community, including users of intravenous drugs, recipients of blood transfusions, and heterosexual partners of infected people. In 1982 the name for the new illness was changed to acquired immunodeficiency syndrome, or AIDS.
While the disease was making headlines for the speed with which it was spreading around the world, the cause of AIDS remained unidentified. Fear of AIDS and ignorance of its causes resulted in some outlandish theories. Some thought the disease was God's punishment for behaviors that they considered immoral. These early theories created a social stigma surrounding the disease that still lingers.
Scientists quickly identified the primary modes of transmission-sexual contact with an infected person, contact with infected blood products, and mother-to-child transmission. From these modes of transmission it was clear that the new illness was spread in a specific manner that matched the profile of a viral infection. In 1983 French cancer specialist Luc Montagnier and his colleagues isolated what appeared to be a new human retrovirus from AIDS patients. They named it lymphadenopathy virus (LAV). Eight months later Gallo and his colleagues isolated the same virus in AIDS patients, naming the virus HTLV-III. Eventually, scientists agreed to call the infectious agent human immunodeficiency virus (HIV). In 1985 a new AIDS-causing virus was discovered in West Africa. Named HIV-2, the new virus is closely related to the first HIV, but it appears to be less harmful to cells of the immune system and reproduces more slowly than HIV-1.
Research leading to the development of the ELISA test was conducted simultaneously by teams led by Gallo in the United States and Montagnier in France. In 1985 the ELISA test to identify HIV in blood became available, followed by the development of the Western Blot test. These tests were first employed to screen blood for the presence of HIV before the blood was used in medical procedures. The tests were later used to identify HIV-infected people, many of whom did not know they were infected. These diagnostic tests also helped scientists study the course of HIV infection in populations.
C

Defining the Illness
The CDC presented its first definition of AIDS in 1982. The CDC recommended that physicians diagnose AIDS if a person has an illness known to be caused by immune deficiency, as long as there is no known cause for this immune deficiency (people who undergo radiation therapy or who take certain drugs may impair their immune systems). As more information became known about the course of HIV infection and the nature of the virus itself, this definition of AIDS was revised repeatedly to expand the list of illnesses considered diagnostic indicators of the disease. Early definitions were based on the opportunistic infections commonly found in HIV-infected men. As a result, many women who did not have symptoms covered in the official AIDS definition were denied disability benefits and AIDS-related drug therapies.
The current definition of AIDS was created in 1993 and includes 26 opportunistic infections and cancers, known as diagnostic indicators, that affect both men and women. The definition also emphasizes the importance of the level of CD4 cells in the blood. Today doctors make the diagnosis of AIDS in anyone with a CD4 count below 200 cells per microliter of blood, regardless of the associated illnesses they may have.

NOW COMPARE THIS WITH THE EARLIER ENTRY

In the early 1980s deaths by opportunistic infections, previously observed mainly in organ transplant recipients receiving therapy to suppress their immune responses, were recognized in otherwise healthy homosexual men. In 1983 French cancer specialist Luc Montagnier and scientists at the Pasteur Institute in Paris isolated what appeared to be a new human retrovirus-a special type of virus that reproduces differently from other viruses-from the lymph node of a man at risk for AIDS (see Lymphatic System). Nearly simultaneously, scientists working in the laboratory of American research scientist Robert Gallo at the National Cancer Institute in Bethesda, Maryland, and a group headed by American virologist Jay Levy at the University of California at San Francisco isolated a retrovirus from people with AIDS and from individuals having contact with people with AIDS. All three groups of scientists isolated what is now known as human immunodeficiency virus (HIV), the virus that causes AIDS.
Infection with HIV does not necessarily mean that a person has AIDS, although people who are HIV-positive are often mistakenly said to have AIDS. In fact, a person can remain HIV-positive for more than ten years without developing any of the clinical illnesses that define and constitute a diagnosis of AIDS. In 1996 an estimated 22.6 million people worldwide were living with HIV or AIDS-21.8 million adults and 830,000 children. The World Health Organization (WHO) estimates that between 1981, when the first AIDS cases were reported, and the end of 1996, more than 8.4 million adults and children had developed AIDS. In this same period there were 6.4 million deaths worldwide from AIDS or HIV. About 360,000 of these deaths occurred in the United States.
Clinical Progression of AIDS
The progression from the point of HIV infection to the clinical diseases that define AIDS may take six to ten years or more. This progression can be monitored using surrogate markers (laboratory data that correspond to the various stages of disease progression) or clinical endpoints (illnesses associated with more advanced disease). Surrogate markers for the various stages of HIV infection include the declining number of CD4 T-cells, the major type of white blood cell lost because of HIV infection. In general, the lower the infected person's CD4 T-cell count, the weaker the person's immune system and the more advanced the disease state. In 1996 it became evident that the actual amount of HIV in a person's blood-the so-called viral burden-could be used to predict the progression to AIDS, regardless of a person's CD4 T-cell count. With advancing technology, viral burden determinations are quickly becoming a standard means of patient testing.
An infected person's immune response to the virus-that is, the person's ability to produce antibodies against HIV-can also be used to determine the progression of AIDS; however, this surrogate marker is less precise during more advanced stages of AIDS because of the overall loss of immune function.
Within one to three weeks after infection with HIV, most people experience nonspecific flulike symptoms such as fever, headache, skin rash, tender lymph nodes, and a vague feeling of discomfort. These symptoms last about one to two weeks. During this phase, known as the acute retroviral syndrome phase, HIV reproduces to very high concentrations in the blood, mutates (changes its genetic nature) frequently, circulates through the blood, and establishes infections throughout the body, especially in the lymphoid organs. The infected person's CD4 T-cell count falls briefly but then returns to near normal levels as the person's immune system responds to the infection. Individuals are thought to be highly infectious during this phase.
Following the acute retroviral syndrome phase, infected individuals enter a prolonged asymptomatic phase-a symptom-free phase that can last ten years or more. Persons with HIV remain in good health during this period, with levels of CD4 T-cells ranging from low to normal (500 to 750 cells per cubic mm of blood). Nevertheless, HIV continues to replicate during the asymptomatic phase, causing progressive destruction of the immune system.
Eventually, the immune system weakens to the point that the person enters the early symptomatic phase. This phase can last from a few months to several years and is characterized by rapidly falling levels of CD4 T-cells (500 to 200 cells per cubic mm of blood) and opportunistic infections that are not life threatening.
Following the early symptomatic phase, the infected person experiences the extensive immune destruction and serious illness that characterize the late symptomatic phase. This phase can also last from a few months to years, and the affected individual may have CD4 T-cell levels below 200 per cubic mm of blood along with certain opportunistic infections that define AIDS. A wasting syndrome of progressive weight loss and debilitating fatigue occurs in a large proportion of people in this stage. The immune system is in a state of severe failure. The person eventually enters the advanced AIDS phase, in which CD4 T-cell numbers are below 50 per cubic mm of blood. Death due to severe life-threatening opportunistic infections and cancers usually occurs within one to two years.
This is what I found in the ULTIMATE edition of
ENCYCLOPAEDIA BRITANNICA (2007) entry on AIDS
Introduction
AIDS ( is an abbrev.) that translates into;  acquired immunodeficiency syndrome transmissible disease of the immune system caused by the human immunodeficiency virus (HIV). HIV slowly attacks and destroys the immune system, the body's defence against infection, leaving an individual vulnerable to a variety of other infections and certain malignancies that eventually causes death. AIDS is the final stage of HIV infection, during which time fatal infections and cancers frequently arise.

·         Human immunodeficiency virus (HIV),
·         colour-enhanced electron microscope image, 24,000×

The emergence of AIDS
AIDS was first reported in 1981 by investigators in New York and California. Initially most cases of AIDS in the United States were diagnosed in homosexual men, who contracted the virus primarily through sexual contact, and in intravenous drug users, who became infected mainly by sharing contaminated hypodermic needles. In 1983 French and American researchers isolated the causative agent, HIV, and by 1985 serological tests to detect the virus had been developed.
HIV/AIDS spread to epidemic proportions in the 1980s, particularly in Africa, where the disease may have originated. Spread was likely facilitated by several factors, including increasing urbanization and long-distance travel in Africa, international travel, changing sexual mores, and intravenous drug use. According to the United Nations 2004 report on AIDS, some 38 million people are living with HIV, approximately 5 million people become infected annually, and about 3 million people die each year from AIDS. Some 20 million people have died of the disease since 1981.
People living in sub-Saharan Africa account for some 70 percent of all infections, and in some countries of the region the prevalence of HIV infection of inhabitants exceeded 10 percent of the population. Rates of infection are lower in other parts of the world, but the epidemic is spreading rapidly in Eastern Europe, India, South and Southeast Asia, Latin America, and the Caribbean. Rates of infection are also on the rise in the United States and Western Europe. In the United States nearly one million people are living with HIV, and half of all new infections are among African Americans. In Asia the sharpest increases in HIV infections are found in China, Indonesia, and Vietnam. Access to retroviral treatment for AIDS remains limited around the world, and the World Health Organization estimates that 9 out of 10 people needing treatment will not receive it.

Transmission
HIV is transmitted by the direct transfer of bodily fluids, such as blood and blood products, semen and other genital secretions, or breast milk, from an infected person to an uninfected person. The primary means of transmission worldwide is heterosexual intercourse with an infected individual; the virus can enter the body through the lining of the vagina, penis, rectum, or mouth.
HIV frequently is spread among intravenous drug users who share needles or syringes. Prior to the development of screening procedures and heat-treating techniques that destroy HIV in blood products, transmission also occurred through contaminated blood products; many people with haemophilia contracted HIV in this way. Today the risk of contracting HIV from a blood transfusion is extremely small.
In rare cases transmission to health care workers may occur by an accidental stick with a needle used to obtain blood from an infected person. The virus also can be transmitted across the placenta or through the breast milk from mother to infant; administration of antiretroviral medications to both the mother and infant around the time of birth reduces the chance that the child will be infected with HIV.
HIV is not spread by coughing, sneezing or casual contact (e.g., shaking hands). HIV is fragile and cannot survive long outside of the body. Therefore, direct transfer of bodily fluids is required for transmission. Other sexually transmitted diseases, such as syphilis, genital herpes, gonorrhoea, and chlamydia, increase the risk of contracting HIV through sexual contact, probably through the genital lesions that they cause.
AIDS is a zoonosis, an infection that is shared by humans and lower vertebrate animals. A virus that is genetically similar to HIV has been found in chimpanzees in western equatorial Africa. Interestingly, this virus, known as simian immunodeficiency virus (SIV), does not readily cause disease in chimpanzees. The practice of hunting and butchering chimpanzees for meat may have allowed transmission of the virus to humans, probably in the first half of the 20th century. A different form of SIV that infects African green monkeys may have given rise to the virus called HIV-2. HIV-2 can cause AIDS, but it does so more slowly than HIV-1. Worldwide, the most common human immunodeficiency virus is HIV-1 found in Europe and the Americas. HIV-2 is found mostly in Asia and Western Africa.
Now that we have read the different entries from the same source, is it any wonder that there is now a concealed politics about the origins and spread of the virus. One account states unequivocally that it emanated from homosexuals in america. After some years the west makes a u-turn to forge that it emanated from blacks in Africa and to complete the falsehood they now manufacture type 1 & type 2.
See how the cunning British Author rephrased the origin "HIV/AIDS spread to epidemic proportions in the 1980s, particularly in Africa, where the disease may have originated. Spread was likely facilitated by several factors, including increasing urbanization and long-distance travel in Africa, international travel, changing sexual mores, and intravenous drug use. …..People living in sub-Saharan Africa account for some 70 percent of all infections, and in some countries of the region the prevalence of HIV infection of inhabitants exceeded 10 percent of the population. Rates of infection are lower in other parts of the world, but the epidemic is spreading rapidly in Eastern Europe, India, South and Southeast Asia, Latin America, and the Caribbean.
 WHEN WILL SCIENTISTS FROM THE WEST BE SINCERE AND REFRAIN FROM DEGRADING THE NEGROID RACE, PAINTING IT BLACKER THAN IT REALLY IS? CAN'T YOU SEE THERE IS NOW A POLITICISATION OF HIV-AIDS!

This is merely a preamble.

I WILL DEBUNK THE DECEIT LATER.
KEEP YOUR FINGERS CROSSED FOR NOW.
EBOLA VIRUS WAS AND STILL IS A POTENTIATION OF ROBERT GALLO'S ORIGINAL TEN-YEAR CREATION OF HIV VIRUS WHICH HE LATER CONFESSED HE WAS COMMISSIONED TO DELIBERATELY DEPOPULATE THE WORLD
Monday, 09 November 2015 @ 14:06:33hrs


DR JIDEOFO KENECHUKWU DANMBAEZUE IS STATING IN UNAMBIGUOUS TERMS THAT BOTH HI-VIRUS AND EBOLA VIRUS WERE MANUFACTURED BY A TEAM OF WHITE SCIENTISTS LED BY DR ROBERT GALLOOF USA, WHO WERE COMMISSIONED TO DEPOPULATE BLACKS BUT INADVERTENTLY THE OBJECTIVE BOOMERANGED AND SO THE POLITICS OF HIV WAS ENTHRONED!!!




 

     


Can someone explain to me, Dr Jideofo Kenechukwu Danmbaezue, why the entries in the 1988 version of Microsoft Encarta encyclopaedia on Acquired Immunodeficiency Syndrome and that of the 2004 version are very different? Why was the detailed history of the development of the virus absent in the latter version? If there is no ulterior motive for this discrepancy, then let someone interpret the etymological meanings of the words: ‘isolated', ‘discovered' and ‘invented' in common day usage of the words! What does each imply, especially the word, ISOLATE ?
THIS IS THE EVIDENCE CLEARLY & UNAMBIGUOUSLY STATED IN THE FIRST 1988 EDITION OF MICROSOFT ENCARTA ENCYCLOPEDIA
In the early 1980s deaths by opportunistic infections, previously observed mainly in organ transplant recipients receiving therapy to suppress their immune responses, were recognized in otherwise healthy homosexual men. In 1983 French cancer specialist Luc Montagnier and scientists at the Pasteur Institute in Paris isolated what appeared to be a new human retrovirus-a special type of virus that reproduces differently from other viruses-from the lymph node of a man at risk for AIDS (see Lymphatic System). Nearly simultaneously, scientists working in the laboratory of American research scientist Robert Gallo at the National Cancer Institute in Bethesda, Maryland, and a group headed by American virologist Jay Levy at the University of California at San Francisco isolated a retrovirus from people with AIDS and from individuals having contact with people with AIDS. All three groups of scientists isolated what is now known as human immunodeficiency virus (HIV), the virus that causes AIDS.   “isolated is used thrice” why this choice of word ?
QUOD ERAT DEMONSTRADUM
  


Dr Jideofo Kenechukwu Danmbaezue, D.Sc.



[1]     "Acquired Immune Deficiency Syndrome," Microsoft® Encarta® 98 Encyclopedia. © 1993-1997 Microsoft Corporation. All rights reserved.