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Wikipedia definition:
Rabies (From
Latin:
rabies. Also known
as “hydrophobia”) is a
viral
neuroinvasive
disease that causes acute
encephalitis
(inflammation of the
brain) in
warm-blooded animals. It is
zoonotic,
that is transmitted by mammals, most commonly by a bite from an
infected animal, but occasionally by other forms of contact. It
is fatal if left untreated. In some countries it is a
significant killer of livestock.
The
rabies virus
makes its way to the brain by following the
peripheral nerves.
The
incubation period
of the disease depends on how far the virus must travel to reach
the
central nervous system,
usually taking a few months. Once
the infection reaches the central nervous system and symptoms
begin to show, the untreated infection is usually fatal within
days.
In the beginning stages
of rabies, the symptoms are
malaise,
headache, and
fever,
while in later stages it includes acute pain, violent movements,
uncontrolled excitements, depressions, and the inability to
swallow water (hence the name hydrophobia). In the final
stages, the patient begins to have periods of
mania and
lethargy,
and coma. Death generally occurs due to respiratory
insufficiency.
Information from CDC Rabies Just 4
Kids:
What is Rabies?
Rabies is a disease that affects wild
animals, domestic animals (like pets and livestock), and humans. It is
caused by a virus. A virus is a very tiny germ. You can see the rabies virus
only with a special electron microscope. Only mammals (warm-blooded animals with
fur) can get rabies.
The word "rabies" comes from a Latin word
that means "to rage." Rabies got its name because animals with rabies sometimes
act as if they are angry. Rabies attacks the brain and spinal cord. It kills you
if not prevented. The best way to prevent rabies is to make sure your pets get
their rabies shots and to avoid contact with wild or stray animals.
How do you get
rabies?
You
get rabies from the saliva of a rabid animal, usually from a bite. The rabies
virus is spread through saliva. It is not spread through contact
with urine, feces, or blood of an infected animal.
You
cannot get rabies by petting an animal. You may get rabies from a scratch if the
animal, such as a cat, was licking its paw before it scratched you. (Remember
that the rabies virus is found in the saliva of an animal).
In
very rare cases, rabies has been spread from one person to another after a
corneal transplant. In several instances, the cornea (part of the eye) from a
person who died of rabies was transplanted to a healthy person, who then got the
disease.
What does the virus
do?
The targets of the rabies virus are nerve
cells. Nerve cells are one part of the body’s nervous system. The nervous
system helps direct body movements. It helps us run, walk, move, sit, and touch.
It also helps us adjust to changes going on around the body, for example by
sweating when it is hot.
The
rabies virus infects the body usually through a bite from a rabid animal. Once
inside the body, the virus travels along the peripheral nerves (the nerves that
run throughout the body). Its main target is the central nervous system, which
is made up of the brain and spinal cord.
How the rabies virus interacts with the nerve cells:
There are four main stages the virus goes
through:
-
Attachment: The rabies virus attaches itself to a healthy nerve cell.
-
Penetration: The virus is taken in by the cell.
-
Replication: Inside the cell, the virus multiplies rapidly.
-
Budding: The new rabies virus leaves the host cell. It attaches to other
nerve cells. The virus then spreads from the brain to the rest of the body
by the nerves.
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