Ebola: A Harbinger Of The End Of The World Essay, Research Paper
Ebola: A Harbinger of the End of the World?
Several years ago, a virus which originated in Africa swept the entire world killing millions. This virus is the commonly known HIV virus, the virus which causes the fatal AIDS disease. In the 1950’s after virologists began the classification of viruses, isolated cases of what are called “hot viruses” began springing up around the world. Most of the deadly viruses were hemorrhagic fever viruses. Some different forms of hemorrhagic viruses are Hantaviruses, Arenaviruses, Flaviviruses, Bunyaviruses, and one of the most dangerous types of viruses, the filovirus. If one of these viruses, especially a filovirus such as Ebola, were to mutate it could concievalby be the end human existance on the planet.
The first of the filoviruses was seen around 1967, identified as Marburg. It killed seven laboratory workers in Germany who were handling monkey blood. The next major filovirus emersion was in 1976. This virus was a more severe virus, Ebola Sudan. It swept across N’zara and Maridi in Sudan. That same year, a strand of Ebola called Ebola Zaire, killed nearly three-hundred people in Yambuku, Zaire. In 1976 Sudan was again hit by Ebola Sudan. More recently, in 1995 Ebola killed more than 200 people in Zaire. Surprisingly, Ebola has reached the United States before. In 1989, Ebola surfaced in a monkey house in Reston, Virginia. The strand of Ebola was called Ebola Reston. It seemed to be airborne, yet harmless to humans. This strain of Ebola was brought to the United States through the trading of monkeys for scientific purposes. (Johnson, as cited in Le Guenno,1995)
Although it may not look like Ebola has done a lot of damage to the human race, take into consideration all of the viruses which are slightly less deadly than Ebola. Arenaviruses alone have killed more than one-hundred fifty people throughout the world in the last forty years. In two outbreaks, Rift Valley Fever, a Bunyavirus, infected nearly a quarter of a million people and 1000 of those infected died. Flaviruses and Hantaviruses have swept across most of Asia infecting millions of people for the last one-thousand years. It should be apparent that these viruses spread easier than Ebola but are not as deadly. Therefore, if one of these viruses was to mutate into a virus with a mortality rate similar to Ebola, it could put a dent in society. (Johnson, 1995)
Currently Ebola is transmitted by contact with bodily fluids from an infected victim. For example, a doctor by the name of Sheth Musoke who worked in a Nairobi hospital in 1980, contracted Marburg when he was splashed with blood and vomit from a dying victim of Marburg. He was lucky enough to survive his ordeal with Marburg, for Marburg only has a twenty-five percent mortality rate.
Most outbreaks of hemmorahagic fever viruses are triggered by the disruption of nature. For instance, in 1989, in a small Venezualian community cleared a forest to make way for more housing and commercial space. Within weeks Guarnarito, a Arenavirus, infected nearly one-hundred people in the town due to a fine dust of contaminated wood which settled over the town. Although most damage to the environment is brought on by humans, in 1993, after heavy snowfall and torrential rains Sin Nombre, a Hantavirus, broke out in New Mexico, Colorado, and Nevada. With the extra rain and snow, grain crops flourished, but along with the grain came the deer mouse, a natural host of Sin Nombre. Sin Nombre infected one-hundred forteen people and killed fifty-eight. Some Hemorrhagic Fever viruses, mainly Bunyaviruses, are carried by mosquitoes. If a dam is built and the water level rises mosquito populations flourish. The action of damming a river caused an outbreak of Rift Valley fever, in 1970. Nearly 600 people died in that outbreak, and almost all of them were bitten by mosquitoes. It is not likely for Ebola to become transmitted by mosquitoes for they do not contain the appropriate proteins for Ebola to flourish. Also, if a mosquito was infected with Ebola it would die within hours due to its small size.
So far Ebola has mutated into many different strains. Originally Ebola mutated from Marburg, another filovirus. From Ebola came Ebola Zaire, then Ebola Sudan, and finally Ebola Reston. Ebola is prone to mutate in the near future because the replication process from cell to cell happens so quickly. When a virus replicates itself, the virus first unwraps itself sorting its seven proteins and its RNA. Then the replication protein starts its job. This protein is dependent on RNA for copying cells. The RNA uses a sort of template to write each of the genes into another RNA message which then tells the host cell to synthesize a specific viral protein. After the cell has made the seven different needed proteins, the RNA copies the entire strand of proteins creating an entire template for a viral cell. New genes are then produced, and proteins wrap themselves around the genes. Then the new viral cell immediately leaves the host cell. (Crusberg and Crowley, 1995)
Unlike other viruses, Ebola does not sit around in the host cell swapping chromosomes until each viral cell has the appropriate chromosomes. Instead, Ebola immediately leaves the cell. Compared to other viruses Ebola is roughing the duplication process so that it can duplicate itself nearly twice as fast. Since the replication process happens so fast the RNA does not have a chance to check the new viral cell it has made; it simply sends the new viral cell off to infect other cells. If the RNA has made a mistake on one single strand of protein the virus could be changed immensely, causing a new strain of the virus. (Crusberg and Crowley, 1995)
Every different virus has different proteins and replicates itself differently. When looked at under an electron microscope the viruses vary greatly in appearance. Many viruses are named for their shape as seen under a microscope. For instance filoviruses were named becuase of their filamentous apperance. Such as:
Ebola, filovirus Lassa, arenavirus
Encephalitis, hantavirus Yellow fever, flavivirus
If a change made the virus airborne, the world population could be decimated. Ebola could then be transported through the air. If one person in Africa was infected with the virus and he got onto a plane flying to America, he would most likely infect every passenger and crew member on the plane. The people on the plane would not realize they were infected for several days. The infected people would then walk through the airport infecting nearly every person they passed. The people in the airport who caught the virus from the original plane of people would then get onto planes going to many different locations throughout the world. Each infected person who got onto a different plane would in turn infect nearly the entire plane. If a flight’s destination was France, a plane full of people infected with Ebola would be traveling throughout France infecting every person they either talked to or breathed on. If this process was to continue worldwide, the well being of every person in the world would be jeopardized due to one single person.
Hypothetically speaking, if the virus was to reach all corners of the earth infecting every person as it went, the world’s population would drop to a mere 500- million, but the virus would still be lurking among the surviving waiting to strike again. If it was to strike again in the same intensity the world population would decrease to 50 million.
It should now be apparent that if Ebola or a similar virus was to mutate into an airborne virus the entire population of the world would be at risk. In the past, many have died from similar viruses and it is probable that as our population continues to grow and we disrupt nature by deforestation and similar activities a more lethal virus will emerge. It is possible that Ebola and other viruses are just a warning from Mother Nature that we are overstepping our boundaries and we are not the most powerful force on the planet.
Addendum: On December twelvth in Liberia the New York times reported that four people who had close contact with a man who caried the Ebola virus had broken out with symptoms of Ebola. They believe this could be the start of a new outbreak. Is this the beginning—of the end?
Axton, Miles (1995). Regulations of a Runaway Replicator.
Netscape, Address Unknown. Pages 1 and 2.
Crowley-John,B.S and Crusberg-Ted,PhD (1995). Ebola and Marburg Viruses: Genomic Structure, Comparitive and Moleculare Biology.
Netscape, Address Unknown. Pages 1 and 2.
Author Unknown(1995). Emerging and Re-Emerging Viruses: An Essay.
Netscape, Adress Unknown. Pages 1-3.
Le Guenno, B.(1995, October). Emerging Viruses.
Scientific American, pp. 56-64.