Discovery Of The Causal Agent Of Aids Biology Essay

One of the World Health Organisations major map is international trailing and monitoring of human diseases. Disease monitoring and surveillance in developed and developing states are carried out by establishments and agents of changing sizes and one such is Centers For Disease Control and bar ( CDC ) in USA. CDC performs a king of beastss portion in international disease monitoring. Information and inside informations of human diseases are fed to CDC by a broad coverage web where it is investigated in item by epidemiologists, statisticians and informations processers.This information is communicated to public wellness workers and scientists throughout the universe by agencies of regular publications such as the hebdomadal Morbidity and Mortality Weekly Report.

Between Oct 1980 and May 1981, an watchful doctor Dr Michael Gottlieb together with co-workers at three different infirmaries in Los Angeles, became intrigued by a bunch of five immature male patients, whose ages ranged from 29 to 36 old ages under their attention. Two of them died and the staying three were earnestly ill. All of them were diagnosed as holding a extremely unusual signifier of pneumonia due to a parasite called Pneumocystis Carinii. Pneumocystis Carinii Pneumonia was antecedently associated with patients with terrible immunosuppression merely. In add-on, all of them were infected with CytomegaloVirus ( CMV ) and had thrush, allof which is characteristic of immunosuppressed patients. In three of the five who were tested had marked perturbations in their functional capacities of their immune system. Another dramatic characteristic was that all of them were sexually active homophiles but none of them cognize each other.

These observation were foremost reported in Morbidity and Mortality Weekly Report of the CDC on 5 June 1981. The 3 July issue had the study of 26 homosexual work forces, 20 from New York and 6 from California with a really uncommon tumour called Kaposi ‘s sarcoma ( KS ) . These work forces were besides found to be harbouring CMV, thrush and PCP.

Therefore, it was at the beginning of the eightiess that the comparatively everyday few instances of homosexual male patients with unusual infections and tumors heralded in an epidemic of one of the most annihilating of all diseases of world. Because of its dramatic consequence of the suppression of the immune system of patients, it was named Acquired Immuno Deficiency Syndrome ( AIDS ) .

Similar forms emerged elsewhere in other states in the developed universe and developing states every bit good. In developed states it was found among homosexual work forces and individuals who injected themselves intravenously with illicit drugs. In developing states it was spread chiefly by heterosexual contact and was common in female cocottes.


A few of the early possibilities under consideration as cause of AIDS were amyl nitrate, seeds, cytomegalo virus and African Swine Fever Virus ( ASFV ) . Two of import scientific finds published a decennary antecedently paved the manner for the development of a engineering that finally enabled the causative virus of AIDS to be isolated. First of such find in 1970 was that of an enzyme called contrary RNA polymerase, which was responsible for the formation of a deoxyribonucleic acid ( DNA ) transcript from a ribonucleic acid ( RNA ) templet, the contrary order of the recognized sequence in biological science. This cardinal find earned for its inventors, David Baltimore and Howard Temin, the Nobel award.

The 2nd of import find on the route to clarifying the cause of AIDS was made in the research lab of Robert Gallo at the National Cancer Institute, Washington DC. In 1976, Gallo discovered a growing factor for mature T – lymph cells which would allow these cells to turn in civilization in the research lab. With the ability now available to turn T – lymphocytes in civilization came the find of a figure of viruses which specifically infect lymph cells ( lymphotropic Viruses ) .

Therefore, following these two of import discoveries, first human retrovirus ( viruses possessing the enzyme contrary RNA polymerase and belonging to the household retroviridae ) was isolated from a patient with leukaemia of mature T-lymphocytes. This virus was called by Gallo as Human T- Lymphotropic Virus I ( HTLV-I ) .A 2nd virus, HLTV-II, was isolated shortly thenceforth from a patient with T -lymphocyte leukaemia.

Another outgrowth of these two finds was the determination of a group of viruses named thenceforth as slow viruses ( Lenti Virus ) in the retroviridae household. These caused slow and drawn-out disease and were responsible for degenerative diseases drawn out over old ages increasingly taking to decease.

In 1983, Dr Francoise Barre – Sinoussi together with Professor Luc Montagnier, the caput of the Viral malignant neoplastic disease unit of the Pasteur Institute, published a paper in the diary Science depicting the isolation of a retrovirus from a patient with lymphadenopathy syndrome, one of the disease manifestations that precedes AIDS, and called it the LAV ( Lymphadenopathy Virus ) . The undermentioned twelvemonth, Robert Gallo and co-workers from the National Institute of Health, USA reported isolation of a retrovirus from AIDS patients and called it Human T cell Lymphotropic Virus -III ( HTLV-III ) . The virus was later given the instead cumbrous name of HTLV-III/LAV to supply equal acknowledgment to both scientific groups. To decide this nomenclatural confusion, the intrenational Committee on Virus Nomenclature in 1986 decided on the generic name “ Human Immunodeficiency Virus ( HIV ) ” .


The beginnings of this singular virus and its every bit singular disease have fired imaginativeness of all time since it was first recognized due to the intense and alone societal, political and human deductions. As on now, the replies to both the beginning of the disease every bit good as to the lineage of the virus remain every bit unresolved as when the inquiries were foremost posed.

One of the earliest of these posits holds that the disease is non a new disease but is instead one of the old endemic disease of Africa which has been soundless or unrecognised. The earliest serum specimen retrieved from archived frozen stuff which was positive for HIV antibodies was taken from a patient in 1959 in the Democratic Republic of Congo. It is barely likely that this virus could hold circulated in adult male much before 1950s and still have been unrecognized.

The 2nd postulated scenario holds that the human virus originated from monkey immunodeficiency virus ( simian immunodeficiency virus/SIV ) . One would necessitate to contend some mechanism by which these viruses could hold been transmitted from monkeys to worlds. The postulated sequence of events with all these “ hypotheses ” therefore relates mutants in monkey virus taking to infection of worlds in Africa followed by the subsequent debut into the Western universe where its spread was accelerated by the sexual revolution and usage of hollow dullard acerate leaf.


The AIDS epidemic has in many ways been a humbling experience to medical scientific discipline. AIDS has likely now go one of the most formidable of all diseases in human history. The four cardinal characteristics which makes it alone are: It is infective and catching from individual to individual, one time infection occurs it follows an grim class and subsequently to decease, septic individuals remain infective for the remainder of their lives, the entire amount of people infected is invariably and increasingly spread outing.

The societal, psychological and political dimensions of the disease compounded the panic generated by it. In western and 3rd universe states it affected the marginalized and victimized section of the society. This association of social rejection together with a morbid apprehension of geting infection, has given rise to alone feelings of repugnance and disapprobation of victims of the disease. This has resulted in many issues in all domains of life which are new to scientists, physicians, psychologists, societal workers, theologists, ethicians, legal experts and politicians.


An apprehension of the general features and morphology of viruses in general will enable us to understand the singularity of HIV.

The word Virus is derived from the Latin word intending ‘poison ‘ and ‘slimy stuff ‘ . Viruss do non fall purely in to the class of unicellular micro beings as they do non possess a cellular organisation. Even the simplest of micro beings are cells enclosed within a cell wall, incorporating both types of nucleic acid ( Deoxy Ribonucleic Acid/DNA and Ribonucleic Acid/RNA ) , synthesising their ain macro molecular components and multiplying by binary fission. Viruss on the other manus do non hold a cellular organisation. They contain merely one type of nucleic acid, either DNA or RNA. They are obligate intracellular parasites.

As a structural entity, the virus represents the simplest biological unit able to be and to perpetuate itself by doing transcripts of itself ( reproduction ) .They are the smallest life agents. Given the structural simpleness, viruses have no capacity to bring forth their ain energy demands for assorted biochemical procedures such as reproduction. The viruses make usage of the host cell ‘s machinery and biochemical installations for their life. In other words, viruses are nil but a group of inert cells outside a life cell ; they are ‘alive ‘ merely inside host cells.

From a molecular geneticist ‘s point of position, virus is a biological entity that transmits familial information between cells therefore prefering mutants and familial alterations. The medical importance of viruses prevarications in their ability to do a broad assortment of human infections. Their opposition to antibiotics differentiates them from higher microbiological signifiers of life.

The broadest grouping of virus is the household. Viruss are classified into two chief divisions depending upon the type of nucleic acid household they possess. Thus there could be riboviruses and deoxyriboviruses. One among the RNA viruses is Retroviridae Family. These are so named due to the presence of the alone enzyme – contrary RNA polymerase – which facilitates production of a Deoxyribonucleic acid transcript from an RNA genome. All members of the household possess this enzyme and all make Deoxyribonucleic acid transcripts of their RNA genomes inside the cells that they parasitize. Retroviridae household has three subfamilies of which HIV belongs to the subfamily Lentivirinae ( lenti = slow ) .

HIV is an enveloped virus about 90 to 120 nanometers in diameter. The cell membrane is

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