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-- This report focuses on the origins of viruses and discusses the ebola virus in particular. -- This report was done to explain the origins of the ebola virus. This virus is one of the most deadly and horrific viruses known to man. To first understand the ebola virus we must first know a little bit about viruses themselves. Viruses themselves are extremely small pieces of matter.
To see them with the naked there would have to be thousands of millions of single viruses joined together. Even some of the most sophisticated compound microscopes cannot see viruses. To see a single virus you would need an electron microscope or something of the sort. Even though viruses are considered non-living a debate still goes on on whether or not they are to be considered alive. They seem to occupy a place midway between the ordinary chemical molecule and the living organism (Viruses and the Nature of Life, Dutton, pg. 8). Most of the time, a virus is as lifeless as a rock, and it may remain so for years.
Yet it may come to life at any moment; all it needs is a vulnerable cell to infect. During an infection the virus might well breed a new strain of virus and will proceed to kill 20, 000, 000 men, women, and children, a record claimed by an influenza virus in 1918. The potency of viruses could easily be demonstrated by ebola. One single ebola virus particle could infect a human and, within hours of waking from a dormant state, produce 10, 000 new ebola viruses, each as ineffective as the original. A visible ball of grouped ebola viruses the size of the tip of a pencil, is enough to infect the entire human race. The virus is essentially a parasite, only able to reproduce inside another living cell.
Once inside the cell however it acts as if it were part of the cell's own complement of chromosomes, and it succeeds in tricking the cell into producing new viruses. No one worried very much about what it meant to be alive before the viruses came along. Animal and plants were alive, mineral were not, and the difference between the tow was obvious. But when the virus was found to occupy some rather vague no-man's land between the domain of animals and that of minerals the old philosophical question, "what is life?" gained new significance.
And at a second glance, it proved to be a profoundly difficult question to answer. The qualities which distinguish the living from the nonliving were not so obvious after all. What should we name as the most important characteristics of living things? They would have to be the ability to reproduce, an organized physical structure, and the ability to react to outside stimuli. In a way, viruses have all of these characteristics.
They can reproduce, but only in other living cells. They have a complex physical structure, but do not contain any organic materials. They also react to outside stimuli. The main characteristic of the virus that makes it non-living is the fact that viruses do not contain both RNA and DNA.
It is known now that viruses can contain one of the other but not both. All things classified as living have both of these acids. The size of the virus is even more significant in terms of the progress of science. In the late 19 th century, living organisms could be found of any and every size between the smallest bacterium and are largest blue whale.
Chemical molecules of every size from complex proteins down to the two atom molecule of hydrogen gas were known. But between the two, between the biologist's living organisms and the chemists inert molecules, there was a great gap. Nothing alive could be smaller than the tiny plueropnuemonia organism measuring some 150 millimicrons. No known chemical molecule was larger than about 22 millions. The world of the biologist and the world of the chemist were neatly separated. (Viruses and the Nature of Life, Dutton, # 23) But in 1898, an organism smaller than any known form of life was discovered something which could reproduce itself and cause disease in tobacco plants.
And in 1935, a molecule larger than any known chemical was isolated and described. Since then, the study of viruses has come a long way. Recently a new virus called ebola came up in the jungles of Zaire and Sedan. This virus was something like the Center for Disease Control and infectious disease centers all over the world had never seen before.
This virus was classified as a filo virus, a virus that causes a very nasty disease known as viral hemorrhagic fever. The natural host for the ebola virus is not known, as it is with most other viruses that cause hemorrhagic fever. All forms of VHF (viral hemorrhagic fever) begin with fever and muscle aches. Depending on the particular virus, the disease can progress until the patient becomes very ill with respiratory problems, severe bleeding, kidney problems, and shock. The severity of VHF can range from a relatively mild illness to death. (Grolier Multimedia Encyclopedia) The ebola virus is a member of a family of RNA viruses known as filo viruses.
When magnified several thousand times by an electron microscope, these viruses have the appearance of long filaments or threads. Ebola virus was discovered in 1976 and was named for a river in Zaire, Africa, where it was first detected. Until recently, only three outbreaks of Ebola hemorrhagic fever among people had been reported. The first two outbreaks were in 1976: one in Zaire and one in western Sudan.
These were large outbreaks, resulting in more than 550 cases and 340 deaths. The third outbreak, in 1979 in Sudan, was smaller, with 34 cases and 22 fatalities. During each of these outbreaks, a majority of cases occurred in hospital settings under the challenging conditions of the developing world. These conditions, including a lack of adequate medical supplies and the frequent reusing of needles and syringes, played a major role in the spread of disease. The outbreaks were quickly controlled when appropriate medical supplies and equipment were made available and quarantine procedures were used.
The source of the Ebola virus in nature remains unknown. In an attempt to identify the source, investigators tested thousands of specimens from animals captured near the outbreak areas, but their efforts were unsuccessful. Monkeys, like humans appear to be susceptible to infection and may serve as a source of virus if infected. (National Center for Infectious Disease, Internet) The recent Ebola virus outbreak is centered in Kikwit, Zaire. (Kikwit is a city of 400, 000 located 400 kilometers east of Kinshasa, the capital of Zaire. ) The outbreak appears to have started with a patient who had surgery in Kikwit on April 10, 1995. Members of the surgical team then developed symptoms similar to those of a viral hemorrhagic fever disease. Ebola hemorrhagic fever was suspected by a Belgium physician who reported the disease to the Zairian government. At the request of Zairian health officials, medical teams from CDC, the World Health Organization, and from Belgium, France, and South Africa are collaborating to investigate and control the outbreak in Zaire.
Symptoms of Ebola hemorrhagic fever begin 4 to 16 days after infection. Persons develop fever, chills, headaches, muscle aches, and loss of appetite. As the disease progresses, vomiting, diarrhea, abdominal pain, sore throat, and chest pain can occur. The blood fails to clot and patients may bleed from injection sites as well as into the gastrointestinal tract, skin, and internal organs.
Ebola virus is spread through close personal contact with a person who is very ill with the disease. In previous outbreaks, person-to-person spread frequently occurred among hospital care workers or family members who were caring for an ill person infected with Ebola virus. Transmission of the virus has also occurred as a result of hypodermic needles being reused in the treatment of patients. Reusing needles is a common practice in developing countries, such as Zaire and Sudan, where the health care system is under financed.
Medical facilities in the United States do not reuse needles. Ebola virus can also be spread from person to person through sexual contact. Close personal contact with persons who are infected but show no signs of active disease is very unlikely to result in infection. Patients who have recovered from an illness caused by Ebola virus do not pose a serious risk for spreading the infection.
However, the virus may be present in the genital secretions of such persons for a brief period after their recovery, and therefore it is possible they can spread the virus through sexual contact. In conclusion the ebola virus is a very deadly disease in which there is no vaccine or cure. The best way to prevent the spread of this disease is by educating developing countries in the ways of proper medical care. The only way to avoid this disease is to prevent exposure to any situation that might pass the disease on.
Free research essays on topics related to: ebola virus, person to person, viral hemorrhagic fever, nature of life, ebola hemorrhagic fever
Research essay sample on Ebola Hemorrhagic Fever Viral Hemorrhagic Fever
