Several years ago, a virus which originated in Africa swept the entire worldkilling millions.
This virus is the commonly known HIV virus, the virus whichcauses the fatal AIDS disease. In the 1950’s after virologists began theclassification of viruses, isolated cases of what are called “hotviruses” began springing up around the world. Most of the deadly viruseswere hemorrhagic fever viruses. Some different forms of hemorrhagic viruses areHantaviruses, Arenaviruses, Flaviviruses, Bunyaviruses, and one of the mostdangerous types of viruses, the filovirus. If one of these viruses, especially afilovirus such as Ebola, were to mutate it could concievalby be the end humanexistance on the planet.
The first of the filoviruses was seen around 1967,identified as Marburg. It killed seven laboratory workers in Germany who werehandling monkey blood. The next major filovirus emersion was in 1976. This viruswas a more severe virus, Ebola Sudan.
It swept across N’zara and Maridi inSudan. That same year, a strand of Ebola called Ebola Zaire, killed nearlythree-hundred people in Yambuku, Zaire. In 1976 Sudan was again hit by EbolaSudan. More recently, in 1995 Ebola killed more than 200 people in Zaire. Surprisingly, Ebola has reached the United States before. In 1989, Ebolasurfaced in a monkey house in Reston, Virginia.
The strand of Ebola was calledEbola Reston. It seemed to be airborne, yet harmless to humans. This strain ofEbola was brought to the United States through the trading of monkeys forscientific purposes. (Johnson, as cited in Le Guenno,1995) Although it may notlook like Ebola has done a lot of damage to the human race, take intoconsideration all of the viruses which are slightly less deadly than Ebola. Arenaviruses alone have killed more than one-hundred fifty people throughout theworld 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 ofpeople for the last one-thousand years. It should be apparent that these virusesspread easier than Ebola but are not as deadly. Therefore, if one of theseviruses was to mutate into a virus with a mortality rate similar to Ebola, itcould put a dent in society.
(Johnson, 1995) Currently Ebola is transmitted bycontact with bodily fluids from an infected victim. For example, a doctor by thename of Sheth Musoke who worked in a Nairobi hospital in 1980, contractedMarburg 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 atwenty-five percent mortality rate. Most outbreaks of hemmorahagic fever virusesare triggered by the disruption of nature. For instance, in 1989, in a smallVenezualian community cleared a forest to make way for more housing andcommercial space. Within weeks Guarnarito, a Arenavirus, infected nearlyone-hundred people in the town due to a fine dust of contaminated wood whichsettled over the town.
Although most damage to the environment is brought on byhumans, in 1993, after heavy snowfall and torrential rains Sin Nombre, aHantavirus, broke out in New Mexico, Colorado, and Nevada. With the extra rainand 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 andkilled fifty-eight. Some Hemorrhagic Fever viruses, mainly Bunyaviruses, arecarried by mosquitoes. If a dam is built and the water level rises mosquitopopulations flourish. The action of damming a river caused an outbreak of RiftValley fever, in 1970.
Nearly 600 people died in that outbreak, and almost allof them were bitten by mosquitoes. It is not likely for Ebola to becometransmitted by mosquitoes for they do not contain the appropriate proteins forEbola to flourish. Also, if a mosquito was infected with Ebola it would diewithin hours due to its small size. So far Ebola has mutated into many differentstrains. Originally Ebola mutated from Marburg, another filovirus. From Ebolacame Ebola Zaire, then Ebola Sudan, and finally Ebola Reston.
Ebola is prone tomutate in the near future because the replication process from cell to cellhappens so quickly. When a virus replicates itself, the virus first unwrapsitself sorting its seven proteins and its RNA. Then the replication proteinstarts its job. This protein is dependent on RNA for copying cells. The RNA usesa sort of template to write each of the genes into another RNA message whichthen tells the host cell to synthesize a specific viral protein. After the cellhas made the seven different needed proteins, the RNA copies the entire strandof proteins creating an entire template for a viral cell.
New genes are thenproduced, and proteins wrap themselves around the genes. Then the new viral cellimmediately leaves the host cell. (Crusberg and Crowley, 1995) Unlike otherviruses, Ebola does not sit around in the host cell swapping chromosomes untileach viral cell has the appropriate chromosomes. Instead, Ebola immediatelyleaves the cell.
Compared to other viruses Ebola is roughing the duplicationprocess so that it can duplicate itself nearly twice as fast. Since thereplication process happens so fast the RNA does not have a chance to check thenew viral cell it has made; it simply sends the new viral cell off to infectother cells. If the RNA has made a mistake on one single strand of protein thevirus could be changed immensely, causing a new strain of the virus. (Crusbergand Crowley, 1995) Every different virus has different proteins and replicatesitself differently. When looked at under an electron microscope the viruses varygreatly in appearance.
Many viruses are named for their shape as seen under amicroscope. For instance filoviruses were named becuase of their filamentousapperance. Such as: Ebola, filovirus Lassa, arenavirus Encephalitis, hantavirusYellow fever, flavivirus If a change made the virus airborne, the worldpopulation 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 planeflying to America, he would most likely infect every passenger and crew memberon the plane. The people on the plane would not realize they were infected forseveral days.
The infected people would then walk through the airport infectingnearly every person they passed. The people in the airport who caught the virusfrom the original plane of people would then get onto planes going to manydifferent locations throughout the world. Each infected person who got onto adifferent plane would in turn infect nearly the entire plane. If a flight’sdestination was France, a plane full of people infected with Ebola would betraveling throughout France infecting every person they either talked to orbreathed on. If this process was to continue worldwide, the well being of everyperson in the world would be jeopardized due to one single person.
Hypothetically speaking, if the virus was to reach all corners of the earthinfecting every person as it went, the world’s population would drop to a mere500- million, but the virus would still be lurking among the surviving waitingto strike again. If it was to strike again in the same intensity the worldpopulation would decrease to 50 million. It should now be apparent that if Ebolaor a similar virus was to mutate into an airborne virus the entire population ofthe world would be at risk. In the past, many have died from similar viruses andit is probable that as our population continues to grow and we disrupt nature bydeforestation and similar activities a more lethal virus will emerge. It ispossible that Ebola and other viruses are just a warning from Mother Nature thatwe are overstepping our boundaries and we are not the most powerful force on theplanet.
Addendum: On December twelvth in Liberia the New York times reportedthat four people who had close contact with a man who caried the Ebola virus hadbroken out with symptoms of Ebola. They believe this could be the start of a newoutbreak. Is this the beginning—of the end?BibliographyAxton, Miles (1995). Regulations of a Runaway Replicator.
Netscape, AddressUnknown. Pages 1 and 2. Crowley-John,B. S and Crusberg-Ted,PhD (1995). Ebola andMarburg Viruses: Genomic Structure, Comparitive and Moleculare Biology. Netscape, Address Unknown.
Pages 1 and 2. Author Unknown(1995). Emerging andRe-Emerging Viruses: An Essay. Netscape, Adress Unknown.
Pages 1-3. Le Guenno,B. (1995, October). Emerging Viruses. Scientific American, pp. 56-64.