Aids Essay, Research Paper
Introduction
The fate of a person who has contracted the virus, which causes AIDS, HIV (Human Immuno-deficiency Virus) is undeniably grim. However when diagnosed with aids it should not be taken as an immediate death sentence. AIDS sufferers can fight off most of the symptoms and live a fairly productive life for many years after diagnosis. The following will be entailed in the body of this AIDS analysis; a description as to what AIDS is, and the difference between AIDS and HIV. The cause of AIDS and what can be done to treat it once it is contracted. A complete description as to how the virus works and why it s so hard to find a cure for the virus. Finally all of the components and parts that make the virus function will be included. Virtually all issues and information regarding the AIDS virus will be touched upon throughout this informative report.
AIDS what is it?
AIDS more formally known as acquired immune deficiency syndrome, is not itself a single disease. More of a drastically damaged or restricted immune system, which leaves AIDS sufferers highly susceptible to a wide range of infections and diseases other than the AIDS itself. AIDS is known to be caused by the human immuno-deficiency virus (HIV), which is spread in several ways. Infected semen, vaginal fluids, and blood are some of the ways it is transmitted. (The Medical Advisor 1997, p.96) Before going too much further into the specifics of AIDS and HIV it is important to clarify the difference.
AIDS vs. HIV what is the difference?
When the disease was first discovered people were only thinking AIDS and what the effects of it would be. But if only AIDS is thought of then an entire stage of the disease is missed. Since AIDS is really only one stage of the HIV virus. Thinking in more correct terms the disease of concern is the HIV infection. AIDS is merely the end stage of the initial infection. A person can become infected with HIV and not have AIDS simply because the AIDS stage has not come into effect yet.
Progression of HIV infection, leading to AIDS:
HIV is a chronic infection meaning that it will continue over a long time, it is also a progressive disease meaning that it will continually get worse. What it actual does is attack and destroy the immune system and produces a wide range of sick and devastating symptoms. These symptoms may however vary from patient to patient. The progress of the disease simply put advances in distinct stages. Also the rate of progression is different among patients. (Packer 1998, pgs.41-2)
The different stages of HIV infection:
The initial exposure to HIV is the first stage to the viral infection. Exposure to HIV as mentioned earlier can be in several ways; through sexual contact in anyway, needle sharing, or blood exposure, or even from mother to infant during child birth. It takes about six weeks after exposure before the victim begins to feel like he/she has the flu. This is known as the early HIV infection stage. Also known as the acute stage. The flu like symptoms may or may not be severe, lasting from 3 to 14 days, in rare cases longer than that. However the downfall to these symptoms is that often victims are unaware of the illness they actually have or are in denial because the individual will recover and seem completely healthy after the flu stage. Once these symptoms dissipate the next stage is then entered. This stage is a more complex stage of the virus known as the asymptomatic stage. At this point there are no symptoms of illness and the person will feel perfectly normal, and this stage can often last up to 10 years or more. Unfortunately during the early HIV infection and the asymptomatic stage the disease is highly infectious. This is a result of such high levels of virus in the body.
After the end of the asymptomatic stage the flu like symptoms will return. This time, however a little more severe. The infected individual will find that they will have large swollen glands, those being the most common symptom. For that vary reason the stage is called the PGL or (persistent generalized lymphadenopathy) stage. This stage can last from three months to a year. (Packer 1998, p.42)
Finally the AIDS stage is reached. However there has yet to be a cure uncovered, no immunity, and no vaccine. The average life expectacy for someone diagnosed with AIDS from time of diagnosis until death is three years. But with recent medical treatments patients are now living longer and longer.
What Causes AIDS?
It is suspected by scientists that there are at least two viruses that cause AIDS: HIV V1 and HIV V2. On a worldly scale the viruses infect equal numbers of people. However in North America HIV V1 prevails. The exact sequence and processes in which HIV undergoes is not entirely known by researchers as of yet. And some are even questioning whether the virus actually causes AIDS or just shows up in union with it. The reason why HIV becomes so harmful to humans is because for some reason it is able to enter the human body through minor cuts or small abrasions, mucous membranes in the mouth, vagina, or rectum without being detected by the immune system. This enables it to cause its damage to T cells without even being spotted causing a complete immune system failure. Patients will then develop infections that will inevitably kill them. Ironically it is not the virus that does the killing it is the other diseases and infections that the immune system fails to stop that kills the patient.
Many believe that AIDS is a highly contagious disease but this is just a misconception. In fact it s not highly contagious at all. The only way it can be contracted as mentioned a few times earlier is through unprotected vaginal, oral, or anal sex with an infected partner, or to share tainted blood, which may occur through IV-drug use or transfusions.
To clarify even further you can not get AIDS from kissing. A protein in human saliva will keep the AIDS virus from infecting white blood cells. The protein will then attach to white blood cells and protects them from infection. This recent discovery may lead to new clinical research and plausible treatment methods. By possibly one day injecting this protein directly into the bloodstream to keep the virus from attacking blood cells. There is also no need to worry about AIDS being transmitted from someone who you live with. It can not be transferred by toilet seats or objects handled by the infected since being outside of the body and being in the hostile environment of the outer world is very harmful to the virus, and almost immediately dies. Nor is it possible for someone to get the virus if you share food with someone who is infected for the same reasons. (The Medical Advisor 1997, p97)
Treatments
It is enevitable for almost everyone who develops full-blown AIDS to eventually succumb to the power of the disease and have a complete body failure and die. Even though this is true there are antibiotic and antiviral drugs that can prolong life for several years. The National Institute of Alergy and Ifectious Diseases or (NIAID) has found a naturally produced protein that may vary well rebuild AIDS damaged immune systems. This newly discovered protein is called interleukin 2, what the protein does is increase the T cell counts in the immune system. However it failed to work for people who were in the advanced stages of AIDS, and unfortunatly it has severe side effects, including rash, nausea, diarrhea, and depression.
Conventional Medicines and Drugs for treatments
There are 3 main types of drug treatments:
1) Nucleoside reverse transcriptase inhibitors (NRTIs). The major drugs under this category include zidovudine (AZT), zalcitabine (ddC), didanosine (ddI), stavudine (D4T), lamivudine (3TC), and abacavir succinate.
2) Non-Nucleoside reverse transcriptase inhibitors (NNRTIs) work in the same way as NRTIs but work on a different part of the virus. The major drugs under this category are delavirdine, nerivapine and efairenz.
3) Protease inhibitors work in a similar fashion to NRTIs, but they interrupt the virus eplication at a later stage in its development. The major drugs in this class include ritonavir, saquinivir, indanvir and nelfavir.
Because HIV can become resistant to drugs at certain stages in its development, they are usually used in combinations. One such drug regimen is called highly active anti-retroviral therapy or HAART. Combinations of drugs are taken orally and the 14 patients tested using this program showed an increase in the lymphocyte cell count.(Eron Joseph..May17, 1999)
Treatments in testing
Vaccines are being investigated, however these vaccines would include a weakened form of the virus. Doctors are reluctant to inject anyone with even a weakened form of the virus for the fear that it may cause an HIV infection. In works related to creating effective vaccines, scientists from NIAID have developed a vaccine with a suicide gene which allows itself to be killed off once its job is complete. Therefore the weakened HIV carries an extra gene taken from the herpes virus. Then the cells, which become infected with the HIV, can be selectively destroyed with a ganciclovir, which is a herpes medicine. The vaccine has only been tested in test tubes so far, but animal and human trials are being planned.
Passive immunotherapy involves injecting late stage AIDS patients with the plasma of early HIV patients with the hopes that the plasmas will boost the advanced patient s immune system and help fight off AIDS associated infections. (The Medical Advisor 1997, ps.97-99)
The Virus and how it works
Amazingly, although not good HIV is one of the most adaptable viruses ever found. It has been described by scientists as the stealth invader, elusive target, and a devious disguiser. The genetic makeup of the virus makes it virtually impossible to stop since it is constantly adapting to medicines and anti-viral drugs. And there are several different strands of HIV.
A Retrovirus
HIV is classified as an RNA or (ribonucleic acid) virus because it s genetic information is contained in RNA instead of DNA or (Deoxyribonucleic acid). The difference is that RNA is a single strand of genetic material that contains inherited traits. Since it belongs to the retrovirus family, it has many features in common. Such as:
h They have two single strands of RNA
h They have a membrane-like outer cover also known as an envelope
h They reproduce or replicate using the DNA of host cells
h They hide themselves in the DNA of the host cell
The task of the retrovirus is to convert their RNA to DNA. This conversion is called reverse transcription, or (retrotransmission). It is necessary to have Reverse Transcription for replication. This also allows the retrovirus use the protein making ability of it s host cell which it would not possess alone. Through the whole process of integration the viruses genetic information begins to look the same as that of the host cell. Making it undetectable by the immune system.
The first step involved for the virus to infect its host is to first make a DNA copy of their RNA. Then a second copy is made. Then this double strand of DNA is incorporated in the host cell s DNA. When the host cell replicates its genetic material in turn it also replicates the viral genetic material. Using this method the virus uses the host as a virus-making factory.(Packer 1998, pg. 34-5) That is why it is impossible to find a cure for HIV and AIDS because the viral information is implanted into the genetic information of the cells. In order to correct this there would have to be some kind of genetic manipulation involved, to remove the viral DNA without damaging the cells.
For visual clarification of the viral producing factory see appendix 1.1
Structure of HIV
HIV actually has a very simple structure. It is a membrane of proteins that contain genetic material inside. The parts are shown in appendix 1.2 Each part not only has a name but there is a reference number to compare part to description.
Envelope Protein:
An outside covering, that serves as a protective membrane. This envelope has glycoprotein, (molecules of sugar and protein) that gives the virus its bumpy look. Each bump has two glycoproteins. One is a top protein (gp120), and the other is a stem like formation, a transmembrane glycoprotein (gp41)
Inner Shell:
An inner shell, or also know as matrix protein (p17), lies beneath the envelope and they are attached.
Core:
HIV has a core of capsid protein (p24). The core surrounds the genetic information
and nucleic acid protein (p7).
RNA:
HIV s genetic material is RNA. The RNA is present as two single strands that contain the genes with specific codes for the viral proteins, viral enzymes, and regulatory proteins of HIV.
Enzymes:
All retroviruses have three enzymes: reverse transcriptase, integrase, and protease. These are the enzymes that help with retroviral replication in the host cell. The reverse transcriptase helps in the building of a single strand of DNA that is a copy of HIV RNA. And also it destroys the original RNA molecule as the new DNA is made.
See appendix 1.2 for diagram relating to parts of HIV virus. (Packer 1998, pg.35-7) for all listed definitions.
Appendix 1.1
Viral Factory in Host Cell
Appendix 1.2
The Parts of the AIDS Virus