AIDS (the acronym meaning Acquired Immuno-deficiency Syndrome or Acquired Immune Deficiency Syndrome, and occasionally written as Aids) is a human disease characterized by progressive destruction of the body's immune system. It is believed by the overwhelming majority of medical opinion to result from infection with HIV, the Human Immunodeficiency Virus (which is actually a retrovirus).
AIDS was first noticed among homosexual men and intravenous drug users in the 1980s; by the 1990s the syndrome had become a global epidemic and in 2004, 58% of those with AIDS were women. While homosexual men continue to suffer higher per capita AIDS rates, the majority of victims are currently heterosexual women, men, and children in developing countries.
AIDS is currently considered incurable; where treatments are unavailable (mostly in poorer countries) most sufferers die within a few years of diagnosis. In the developed countries, treatment has improved greatly over the past decade, and people have lived with AIDS for ten to twenty years.
HIV is transmitted by bodily fluids, such as blood, semen and vaginal secretions. It causes disease by infecting CD4+ T cells, a type of leukocyte (white blood cell) that normally co-ordinates the immune response to infection and cancer. When a person's CD4+ T cell count decreases sufficiently he or she is prone to a range of diseases that a healthy person's body is normally able to fight. These diseases include cancers and opportunistic infections, which are usually the cause of death in persons with AIDS. HIV also infects brain cells, causing some neurological disorders.
Originally AIDS was diagnosed based on the opportunistic diseases affecting the patient. Today diagnosis is based on CD4+ T cell counts. This allows for earlier diagnosis and better representation of women.
Many opportunistic diseases are associated with AIDS:
candidiasis, disseminated or of the oesophagus and/or lungs
lymphoma, Burkitt's or primary lymphoma of the brain ("AIDS-related lymphoma")
Mycobacterium avium complex (MAC) infection or M. kansasii infection, disseminated or extrapulmonary Mycobacterium tuberculosis, disseminated, any site
Mycobacterium, other species, disseminated or extrapulmonary
While KS and PCP were not unknown to physicians, the tight clustering of cases was considered highly unusual. Most patients identified were sexually active homosexual men, many of whom were also discovered to be suffering from other chronic diseases later identified as opportunistic infections. Blood tests revealed that many of the patients were also lacking in adequate numbers of a class of white blood cells called CD4+ T cells. Many of the patients died within a few months.
Since most of the originally identified sufferers were homosexual men, the syndrome was initially referred to by doctors as "GRID" (Gay-Related Immune Deficiency), and was referred to in some sections of the media as "the gay plague." Almost at once, however, it was realised that the infected population included Haitian immigrants, intravenous drug users, blood transfusion recipients, and heterosexual women as well. The disease was officially renamed AIDS in 1982.
Until 1984, there were a number of theories about the possible causes of AIDS. The most widely held theory, right from the start, was that AIDS was caused by a virus. The evidence for this was mainly epidemiological. In 1983 a group of nine gay male AIDS patients in Los Angeles with interlocking sexual contacts, including a sexual contact in New York shared by three of the Los Angeles men who were strangers to each other was described; this group became known as the "Los Angeles Cluster." This pattern immediately suggested that an infectious agent was responsible.
Other possible theories at this time included the "immune overload" theory, popularised in the gay press by the activist Michael Callen. This theory suggested that AIDS arose from the effects of excessive drug use and sexual promiscuity among so-called "fast lane" gay men. It was also suggested that the anal intake of semen during anal sex, when combined with the use of nitrite inhalants (known as "poppers"), might suppress the immune system. Few medical specialists accepted these theories, but they became established among non-medical commentators and are still promoted by some of those who deny that HIV causes AIDS.
In the early years of AIDS, the exact origin of the virus causing AIDS was unknown. A common theory, which even became the subject of an article in Rolling Stone Magazine, held that HIV came from Simian Immunodeficiency Virus (SIV), a virus virually identical to HIV, that causes AIDS-like symptoms in primates, and that this virus was transmitted to human populations in Africa during the course of controversial polio vaccine experiments on African villagers. The theory that the virus was transmitted during the polio vaccine experiments has since been disproven.
It was also commonly believed that the spread of AIDS to the western world was attributable to the sexual behaviour of a single man known as Patient Zero, a Canadian flight attendant who was said to have had sex with over 1,000 men in various countries. This theory, popularised by the gay journalist Randy Shilts in his book And the Band Played On, and later made into a movie, has since been disproven.
In 1984 two scientists, Dr Robert Gallo in the United States and Professor Jean Luc Montagnier in France, independently isolated the virus which causes AIDS. After a prolonged dispute, they agreed to share credit for its discovery, and it was given the name Human Immunodeficiency Virus (HIV) in 1986. The discovery of the virus allowed the rapid development of an antibody test, which allowed people at risk to know whether they were infected and therefore at risk of developing AIDS. It also allowed research on possible treatments and a possible vaccine to begin.
Sufferers of AIDS in the early days were frequently ostracized by their communities, friends, and even families. Ryan White, for example, was a young American boy who contracted AIDS through a blood transfusion, and was forced to withdraw from school because of protests by the parents of other children. Sufferers were isolated; people were afraid to be close to them as it was commonly believed that AIDS could be transmitted by casual contact such as holding hands, kissing, hugging, or sharing cups, dishes or eating utensils.
Gay men were frequently blamed for the advent and spread of AIDS in the West. Some claimed that AIDS was a punishment from God for homosexuality (this belief is still espoused by some religious groups, both Christian and Islamic). Others claimed that the "depraved lifestyles" of gay men were responsible. It is true that in the early years AIDS spread quickly through gay communities and that a majority of early sufferers were gay men, but this is in part due to the fact that birth control was unnecessary with same-sex partners so gay men were unlikely to use condoms, now considered one of the best ways (other than abstinence) to prevent the spread of HIV.
The initial focus on gay men proved very damaging since it distracted attention from the rapid spread of HIV infection among heterosexuals, particularly in Africa and the Caribbean, and later in parts of Asia, and, some believe, because institutionalized homophobia prevented quick action against HIV and AIDS.
HIV is closely related to viruses causing AIDS-like diseases in many primates, and is generally thought to have been transferred from animals to humans at some time during the early 20th century, though some evidence suggests it may have been transferred earlier in several isolated cases. The exact animal source, time, and location of the transfer (or indeed, how many transfers there were) is not currently known. SIV, a virus virtually identical to HIV, has been found in chimpanzees, but it is not known for certain whether the transmission was from chimpanzees to humans, or whether both chimpanzees and humans were infected by a third source.
Studies suggest that the virus spread initially in West Africa, but it is possible that there were several separate initial sources. The earliest human fluid sample known to contain HIV was taken in 1959 from a British sailor, who apparently contracted it in what is now the Democratic Republic of the Congo. Other early samples include one from an American male who died in 1969, and a Norwegian sailor in 1976. It is believed that the virus was spread via sexual activity, possibly including with prostitutes, in Africa's rapidly growing urban areas. As unwittingly infected people traveled the virus spread from one city to another, and air travelers carried the virus to other continents.
Currently the most common ways to contract HIV are via unprotected sexual activity and the sharing of needles by users of intravenous drugs. The virus is rarely transmitted from mother to child in the womb, but HIV can be transmitted during childbirth or through breastfeeding. Blood transfusions and the use of blood products to treat haemophilia have also been major routes of infection in the past, leading to stricter screening procedures (but despite these new measures such cases are still reported occasionally).
Not every patient who is infected with HIV is considered to have AIDS. The criteria for a diagnosis of AIDS can vary from region to region, but a diagnosis typically requires either:
an absolute CD4 cell count below 200 per cubic millimetre, or
the presence of opportunistic infections, caused by agents usually unable to induce diseases in healthy people
A person who is infected with HIV is said to be HIV+ (HIV positive or seropositive) and is sometimes referred to as a PWH, or Person With HIV. An uninfected individual is said to be HIV- (HIV negative or seronegative). HIV+ individuals are frequently unaware of their HIV status. Persons with AIDS (PWAs) are also said to be HIV+, and PWHs and PWAs are sometimes collectively referred to as PWAs or PWH/As. In recent years the more optimistic term "People Living With AIDS" (PLWAs) has come to be preferred by AIDS activist groups and many people with AIDS themselves.
Primary infection with HIV is called seroconversion, and may be accompanied by what is called "seroconversion illness" (an earlier term was "AIDS prodrome"). Symptoms of seroconversion illness include mild flu-like symptoms such as fever, aching muscles and joints, sore throat, and swollen glands (lymph nodes), but may also include other symptoms such as rash. Not every person who seroconverts experiences seroconversion illness, and there are people who experience no symptoms at all at this stage.
Regardless of the presence or absence of initial symptoms, all newly infected individuals become asymptomatic (symptom-free). The newly infected patient is actually most infectious during the seroconversion illness as it is during this time that the HIV viral load in the blood plasma is highest. At this stage, the virus is still multiplying rapidly, unchecked, because the body has not yet started to produce antibodies to the virus in sufficient quantities to reach an equilibrium.
During the asymptomatic stage, billions of HIV particles are produced every day accompanied by a decline, at variable rates, in the number of CD4+ T cells. The virus is not only present in the blood, but also throughout the body, particularly in the lymph nodes, brain, and genital secretions. During this stage, the body's immune system is actively trying to fight off the HIV infection but, for the vast majority of infected people who are not receiving treatment, the immune response is insufficient as the virus directly attacks cells of the immune system and mutates rapidly.
The time from infection with HIV to a diagnosis of AIDS varies. Some patients develop symptoms within a few months of infection, while others are known to have remained completely asymptomatic for as long as 20 years. These people who remain asymptomatic are often called Long-term AIDS nonprogressors. Why these nonprogressors remain AIDS-free, and why different people advance at various rates, is currently unknown, and is the subject of ongoing study. The average time of progression from initial infection to AIDS is eight to ten years in the absence of treatment.
There is ongoing research into developing a vaccine for HIV and in developing new anti-retroviral drugs. Human trials are currently underway. Research to improve current treatments includes simplifying current drug regimens to improve adherence and in decreasing side effects.
Ever since AIDS entered the public consciousness, various forms of alternative medicine have been used to treat its symptoms. In the first decade of the epidemic when no useful conventional treatment was available, a large number of PWAs experimented with alternative therapies of various kinds, including massage, herbal and flower remedies and acupuncture, to either combat the virus or to relieve related symptoms. None of these were shown to have any genuine or long-term effect on the virus in controlled trials, but they may have had other quality of life-enhancing effects on individual users. Interest in these therapies has declined over the past decade as conventional treatments have improved. They are still used by some people with AIDS who do not believe that HIV causes AIDS. Alternative therapies such as massage, acupuncture and herbal medicine are still used by many sufferers in conjunction with other treatments, mainly to treat symptoms such as pain and loss of appetite. People with AIDS, like people with other illnesses such as cancer, also sometimes use marijuana to treat pain, combat nausea and stimulate appetite.
Mainstream AIDS activists characterize the position of these dissidents as "AIDS denialism," and believe their public proselytization for their various theories is destructive to the adoption of appropriate preventive and therapeutic measures. Active advocacy of these theories is largely confined to radical gay activist groups such as ACT-UP in San Francisco. (Not to be confused with ACT-UP/Golden Gate, which split from ACT-UP San Francisco in 1990, and changed its name in 2000 to avoid association with ACT-UP/San Francisco's non-mainstream views). As with the enthusiasm for alternative therapies, advocacy of unorthodox views about AIDS has declined with the increasing success of orthodox medical approaches to AIDS therapies.
By the turn of the 21st century AIDS had become a global epidemic, affecting people in virtually every country, and in many countries it shows no signs of slowing down. It is estimated that by 2003 over 40 million people worldwide were HIV-positive and that about 19 million had died from AIDS-related illnesses. These numbers have led some experts to call AIDS the deadliest pandemic in human history since the Black Death of the 14th century.
In Western countries the infection rate of HIV has slowed somewhat, due to the widespread adoption of safe sex practices by gay men and (to a lesser extent) the existence of needle exchanges and campaigns to educate intravenous drug users about the dangers of sharing needles. The spread of infection among heterosexuals in western countries has Source | Copyright
