Origin of HIV/AIDS

By: Johnson Pinto

Origin of HIV/AIDS Most people believe that the origin of HIV, the AIDS virus, derives from some natural evolutionary event. The HIV origin theories is called "cut hunter theory" .The origin of AIDS and HIV has puzzled question inside the scientists ever since this illness first came to light in the early 1980s. For over twenty years it has been the subject of fierce debate and the cause of countless arguments, with everything from a promiscuous flight attendant to a suspect vaccine programmed being blamed. So what is the truth? Just where did AIDS come from? HIV was first identified in the United States in 1981 after a number of gay men started getting sick with a rare type of cancer. It took several years for scientists to develop a test for the virus, to understand how HIV was transmitted between humans, and to determine what people could do to protect themselves. The first registered cases in the U.S. occurred in New York City in 1952, 1959, and 1979. The cases from the 1950s were both males with PCP and other unusual infections. A Congolese man's blood sample from a medical study was preserved, found, and then analyzed in 1998. It was verified that he had been HIV+. Other suspected, but unverified because of the lack of either blood or tissue samples, cases date back as early as 1934. On February 1, 2000, M. Korber, et al. reported the results of a phylogenetic statistical analysis of the evolution of the retroviral genome of HIV using complex mathematical models allowing for both constant and variable rates of evolution. Her group's analysis required the use of supercomputers to backtrack the evolution to its source from monkeys. The most reliable time of origin in humans is somewhere around 1930 (a 95% confidence interval extends from 1910 to 1950). Several naysayer have claimed that the disease originated from the use of African green monkey kidneys to cultivate poliovirus in the late 1950's and early 1960's. This analysis finds that argument to be a very low probability event, hence quite unlikely. The hepatitis B vaccine was not considered by this esteemed gathering. Suspiciously neglected, this vaccine was produced in chimpanzees during pilot testing conducted in New York City, among gay men, and Central African villagers between 1972 and 1974. This was precisely timed for the emergence of AIDS in these exact, demographically distinct, communities by the late 1970s. The fact that this fact was neglected proves shoddy science or gross negligence at best. HIV-2 for example SIV a strain of the Simian Immunodeficiency Virus found in the sooty mangabey (also known as the White-collared monkey), which is indigenous to western Africa.

 The more virulent, pandemic strain of HIV, namely HIV-1, was until recently more difficult to place. Until 1999, the closest counterpart that had been identified was SIV,the SIV found in chimpanzees. However, this virus still had certain significant differences from HIV. The most commonly accepted theory is that of the 'hunter'. In this scenario, SIVcpz was transferred to humans as a result of chimps being killed and eaten or their blood getting into cuts or wounds on the hunter. Normally the hunter's body would have fought off SIV, but on a few occasions it adapted itself within its new human host and become HIV-1. The fact that there were several different early strains of HIV, each with a slightly different genetic make-up (the most common of which was HIV-1 group M), would support this theory: every time it passed from a chimpanzee to a man, it would have developed in a slightly different way within his body, and thus produced a slightly different strain. Some scientists identified a type of chimpanzee in West Africa as the source of HIV infection in humans. The virus most likely jumped to humans when humans hunted these chimpanzees for meat and came into contact with their infected blood. Over several years, the virus slowly spread across Africa and later into other parts of the world. An article published in The Lancet in 20043, also shows how retroviral transfer from primates to hunters is still occurring even today. In a sample of 1099 individuals in Cameroon , they discovered ten (1%) were infected with SFV (Simian Foamy Virus), an illness which, like SIV, was previously thought only to infect primates. All these infections were believed to have been acquired through the butchering and consumption of monkey and ape meat. Discoveries such as this have led to calls for an outright ban on bush meat hunting to prevent simian viruses being passed to humans. Where did HIV originate? First, HIV-2 is very closely related to SIV, the simian immune virus, found in sooty mangabeys. Baboons can be infected with HIV-1 and they can also suffer from a version of SIV. At the 6th American Conference on Retroviruses and Opportunistic Infections held in Chicago from January 31-February 4, 1999, one of the keynote papers delivered by Beatrice Hahn on the first day presented evidence that HIV-1 is likely to have originated in West African chimpanzees .HIV could have been transferred from monkeys because they have long been kept as pets and used for food. When hunting monkeys it is not unusual for both the hunter and the hunted to exchange blood during capture. Currently there is a large market in "bush meat" obtained from monkeys. This does not bode well because there may well be continuing transfer of the disease from monkeys to humans.  In 2001, The Royal Society of London's conference proceedings, which sought to determine the initial cause of AIDS and the origin of HIV, were published for the world to behold. The most highly respected scientists and academicians debated the possibility that HIV-1, the most widespread and deadly human AIDS virus, evolved from accidental vaccine contaminations and subsequent transmissions to mostly African villagers. The oral polio vaccine (OPV) received the focus of interest here since that vaccine was partially derived from growing live polio viruses in monkey kidney cells that have historically proven to be contaminated with cancer viruses such as SV40 -- the 40th monkey virus ever discovered. This virus, like HIV-1, is currently linked by medical scientists to widespread human cancers. By the end of the symposium, the esteemed delegates concluded HIV's origin, and AIDS, was not likely to have come from polio vaccine transmissions as chimpanzees were not proven to have been used during the manufacture of this vaccine. . In 2008, CDC adjusted its estimate of new HIV infections because of new technology and developed by the agency. Before this time, CDC estimated there were roughly 40,000 new HIV infections each year in the United States. New results shows there were dramatic declines in the number of new HIV infections from a peak of about 130,000 in the mid 1980s to a low of roughly 50,000 in the early 1990s. Results also shows that new infections increased in the late 1990s, followed by a leveling off since 2000 at about 55,000 per year. AIDS cases began to fall dramatically in 1996, when new drugs became available. Today, more people than ever before are living with HIV/AIDS. CDC estimates that about 1 million people in the United States are living with HIV or AIDS. About one quarter of these people do not know that they are infected: not knowing puts them and others at risk.


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