Ebola Essay, Research Paper

Ebola

“The single biggest threat to man s continued dominance on the planet is the virus”

Dr. Joshua Lederberg

Nobel Laureate

Forget cancer and AIDS. This virus does in two days what either of those takes years to accomplish. This is one of the most ruthless viruses known to man. It kills nine out of ten of its victims. There is no vaccine, no cure.

A virus is a disease-causing organism, that lives in a cell of another living thing. By itself, a virus is a lifeless particle that cannot reproduce. But inside a living cell, a virus becomes active and can multiply hundreds of times, usually harming or destroying the host in the process. Viruses cannot live for long outside a cell. They must be carried inside the organism by some means and then transported through body fluids, to the cells.

As the virus reproduces itself, the copies, are released from the cell and infect other cells. When a virus reproduces, it changes the chemical make up of a cell. This change usually damages or kills the cell, and disease results if many cells are infected.

The Ebola (pronounced ee-BOH-la) virus is an extremely lethal virus from the tropics, its exact origins unknown. It affects monkeys and humans. It is member of a family of RNA viruses known as filoviruses. When magnified several thousand times by an electron microscope, these viruses have the appearance of long filamates or threads. The thread viruses have been compared to hair, to worms and to snakes, when they appear in a great flooding mess, as they so often do when they have destroyed a victim, they look like a tub of spaghetti that has been dumped on the floor. It is closely related to the Marburg virus. Ebola was discovered in 1976 and was named for a river in Zaire, Africa where it was first detected.

There are four known strands of Ebola that are known to exist, Ebola Zaire (EBOZ), Ebola Sudan (EBOS), Ebola Reston (EBOR), and Ebola Tai (EBOT). Ebola Zaire is the most common variety, unfortunately it is also the most lethal, at a 90% fatality rate. Sudan s death rate is at 60%. And Tai, the most recently discovered strand, has no sufficient epidemiological data to determine a fatality rate. Ebola Reston from (Richard Preston s book) The Hot Zone fame is not fatal to humans but deadly to monkeys.

Ebola is spread through close personal contact with a person who is very ill with Ebola. The incubation period is anywhere from two to 21 days, although 7-14 is the most common. In previous outbreaks, person to person contamination frequently occurred among hospital care workers or family members who were caring for an ill person infected with Ebola. Blood and body fluids contain large amounts of virus, thus transmission of the virus has also occurred as a result of hypodermic needles being reused in the treatment of patients. Reusing needles in developing countries such as Zaire and Sudan, where the health care system is underfinanced is a common practice. Many hospitals in poor regions of Africa lack fresh water, rubber gloves, gowns, and other sanitized supplies that can prevent the transmission of disease. Medical facilities in the United States do not reuse needles and have much better sanitary conditions.

There is no evidence of airborne transmission of Ebola between humans. There have been no clinically proven cases of airborne transmission between monkeys; however there was a recent report that two control monkeys caged across the room from monkeys with Ebola Zaire died of Ebola Zaire. Further work is needed to clarify this finding. The Reston strain appears to have been transmitted by airborne means, but that strain is not harmful to humans.

Here are the CDC s comments on the chances of Ebola becoming “airborne” “To become airborne, the Ebola RNA would have to mutate in such a way that it s outer protective coating of proteins could resist the forces to which they are subjected to in the air (i.e. dryness). It also would probably need to change structure to allow infection through the respiratory system. There are no exact measures of the rate of mutation in Ebola but the probability of the required mutation(s) happening are very slim.”

“Once infected headaches begin, a fever spikes, and the victim begins to vomit. The vomiting becomes intense and turns into dry heaves. Blood starts to hemorrhage out of every orifice in the body. Blood starts to clot everywhere, liver, kidneys, lungs, hands, feet, the head jams with blood clots, it s a virtual stroke throughout the whole body. The organs start to liquefy. Then the human virus bomb explodes. The victim become dizzy and utterly weak, the spine goes limp and nerveless. You then “crash and bled out”. A sound like a bedsheet being torn in half, which is the sound of the bowels opening and venting blood from the anus. The blood is mixed with intestinal lining. An incredible quantity of blood spills out around the victim, a pool of blood, and the pool is enlarging rapidly. The virus has destroyed it s host and is trying to find a new host.” From Richard Preston’s book The Hot Zone

In the summer of 1995, after an 18-year hiatus, Ebola struck Kikwit, Zaire. The virus claimed the lives of more than 200 people. 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 symptons.

There have been only four known, outbreaks among humans: Ebola Zaire in 1976, Ebola Sudan, also in 1976, another Sudan outbreak in 1979, and the Ebola Zaire outbreak in Kikwit in 1995. The Ebola Reston outbreak in 1989 affected only monkeys. A Swiss researcher who survived her Ebola Tai infection is the only know case of that strain so far.

Outbreaks of Ebola hemorrhagic fever are successfully controlled through the isolation of the sick in a place requiring the wearing of a mask, gown and gloves; careful sterilization of needles and syringes; and proper disposal of waste and corpses. There is no known cure for Ebola fever. Current therapy consists of maintaining fluid and electrolyte balance and transfusions of blood and plasma to control bleeding. There is some hope offered by recent reports of an anti serum being developed. The problem with this is Ebola serum therapy needs to be strain specific, (meaning EBOZ serum can t cure EBOS). Also if immunity exists after infection it is likely strain-specific. Ebola is too lethal for it s own good. It s victims die so quickly that they don t have a chance to spread the virus very far.

Despite 16 years of scientific research and field investigations, the origin of the Ebola virus remains a mystery. Scientists expect that it has probably circulated in wild animals such as rodents for years, and only makes the jump into humans when the two populations come into contact. Observes Yale epidemiologist Dr. Robert Ryder, “This virus basically says to man, You stick to your territory and I ll stick to mine. But then man begins to encroach on the habitat of the viruses.” The emerging viruses are surfacing from ecologically damaged parts of the earth. Many of them come from the edges of the tropical rain forest, or they come from tropical savanna that is being settled rapidly by people. The tropical rain forests are the deep reservoirs of life on the planet, containing most of the world s plant and animal species. The rain forests are also its largest reservoirs of viruses, since all living things carry viruses. Which means that the next time the Ebola virus emerges from the jungle it might be much harder to control.