A Virus Essay

This essay has a total of 1539 words and 6 pages.

A Virus



A virus is an ultramicroscopic infectious organism that, having no independent metabolic
activity, can replicate only within a cell of another host organism. A virus consists of a
core of nucleic acid, either RNA or DNA, surrounded by a coating of antigenic protein and
sometimes a lipid layer surrounds it as well. The virus provides the genetic code for
replication, and the host cell provides the necessary energy and raw materials. There are
more than 200 viruses that are known to cause disease in humans. The Ebola virus, which
dates back to 1976, has four strains each from a different geographic area, but all give
their victims the same painful, often lethal symptoms.

The Ebola virus is a member of a family of RNA viruses’ known as ‘Filoviriade' and falling
under one genus, ‘Filovirus'. Marburg is a relative of the Ebola virus. The four strains
of Ebola are Ebola Zaire, Ebola Sudan, Ebola Reston, and Ebola Tai. Each is named after
the geographical location in which it was discovered. These filoviruses cause hemorrhagic
fever, which is actually what kill victims of the Ebola virus. Hemorrhagic fever as
defined in Mosby's Medical, Nursing, and Allied Health Dictionary as, a group of viral
aerosol infections, characterized by fever, chills, headache, malaise, and respiratory or
GI symptoms, followed by capillary hemorrhages, and, in severe infection, oliguria, kidney
failure, hypotension, and, possibly, death. The incubation period for Ebola Hemorrhagic
Fever ranges from 2-21 days. The blood fails to clot and patients may bleed from
injections sites and into the gastrointestinal tract, skin and internal organs. The Ebola
virus has a tropism for liver cells and macrophages, macrophages are cells that engulf
bacteria and help the body defend against disease. Massive destruction of the liver is a
hallmark feature of Ebola virus infection. This virus does in ten days what it takes AIDS
ten years to do. It also requires biosaftey level four containment, the highest and most
dangerous level. HIV the virus that causes AIDS requires only a biosaftey level of two. In
reported outbreaks, 50%-90% of cases have been fatal. Ebola can be spread in a number of
ways, and replication of the virus occurs at an alarming rate. Ebola replication in
infected cells takes about eight hours. Hundreds to thousands of new virus particles are
then released during periods of a few hours to a few days, before the cells die. The
several cycles of replication occur in a primate before the onset of the fever and other
clinical manifestations. In most outbreaks, transmission from patient to patient within
hospitals has been associated within the reuse of unsterile needles and syringes. High
rates of transmission in outbreaks have occurred from patients to heath-care workers and
to family members who provide nursing care without appropriate precautions to prevent
exposure to blood, other body fluids, vomitus, urine and stool. Risk for transmitting the
infection appears to be highest during the later stages of illness, which are often
characterized by vomiting, diarrhea, shock, and frequently hemorrhaging. Even a person
who has recovered from the symptoms of the illness may have the virus present in the
genital secretions for a brief period after. This makes it possible for the virus to be
spread by sexual contact. Complete recovery is reached only when no particles of the virus
are left in the body fluids, this however is rarely attained. The disease, for humans, is
not airborne, capable to be passed on through air travel, but for nonhuman primates it has
been a possibility in a few cases.

Ebola Zaire was identified in 1976 in Northern Zaire and was the first documented
appearance of the virus. This strain of the virus effects humans and nonhuman primates.
Close contact and dirty needles spread the Ebola virus. The center of the epidemic in
Zaire involved a missionary hospital where they reused needles and syringes without
sterilization. Most of the staff of the hospital got sick and died. This outbreak infected
318 with a death rate of 93%. Another fatal case was reported one year later in Zaire but
nothing major ever became of it. The most recent case recorded was the infamous breakout
in Kikwit, Zaire. This breakout had the world in an uproar about the possibility of this
virus-spreading out globally. This outbreak appeared 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. From there, the disease
spread to more than 300 others. The most frequent symptoms at the onset were fever (94%),
diarrhea (80%), and server weakness (74%); other symptoms included dysphagia (41%) and
hiccups (15%). Clinical signs of bleeding occurred in 38% of cases. The World Heath
Organization declared on August 24, 1995 that the outbreak of Ebola Zaire in Kikwit was
officially over after killing 244 of its 315 known victims. This outbreak had a rate of
death over 75%.

Ebola Sudan also occurred in 1976 about the same time as Ebola Zaire. The number of cases
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