3. • This means that it is a lethally infective agent.
• The Ebola virus has a prime directive to replicate,
like any other known virus on this planet.
• The reservoir species of the Ebola is UNKNOWN,
thus the major part of the LIFE CYCLE of the virus
is UNKNOWN .
• Fruit Bat is the most common culprit of the Ebola
Virus
Ebola : A “HotVirus”
5. The Name Ebola
August 26, 1976 inYambuku, a town in the north of
Zaïre. A 44-year-old school teacher returned from a
small hike. His went to the doctor and because of his
high fever they gave him a quinine shot which is good
against malaria.
A week later, he had uncontrolled vomiting, bloody
diarrhea, trouble breathing and then bleeding from his
nose, mouth, and anus.
He died ~14 days after the onset of symptoms.
He started an epidemic that killed 280 of the 313
infected persons (88%).
6. Ebola
The virus kills gorillas
and chimpanzees and
other monkeys. Because
it kills apes in such high
percentage – they are
not likely to be its
natural host.
8. Three trapping expeditions in areas close to
infected gorilla and chimpanzee carcasses in
Gabon and in Congo.
1,030 animals were tested including 679 bats,
222 birds and 129 small terrestrial vertebrates
(PCR).
Viral nucleotides were discovered in 3 species of
bats.
9. The Ebola virus, once inside a host,
begins to replicate. The seven proteins
that make up the body of the virus
begin to consume the host cell as the
virus starts making copies of itself .
Replication Using Proteins
10. Ebola multiply extremely rapidly and powerfully that within
no time the infected cell becomes packed with crystal like
blocks of virus particles . These virus particles are themselves
getting ready to replicate.
The crystal like blocks, or bricks, form at the centre of the
cell and begin to grow outwards, migrating to the cell wall.
On reaching the cell wall, the brick dissolves into hundreds
of individual virus particles
The Ebola virus particles then infiltrate the bloodstream of
the host and keep attaching themselves to cells everywhere.
Here the procedure of replication is repeated until the tissue
becomes saturated with virus crystal bricks.
Virus Bricks
11. This amplification continues till even a
droplet of blood of the host can contain
up to 100 million virus particles.The
Ebola virus thus destroys its host and
“seeks” a new one. Like any other
virus, the Ebola cannot survive by itself
and needs either a reservoir or host for
its continued existence.
Amplification of theVirus
12. It is believed that the virus is mainly transmitted
through contact with the blood of an infected person
or primate, either directly or indirectly, for example
through the use of an infected syringe
It is known that the Ebola virus is spread from person
to person through direct contact with body fluids
(e.g., blood, semen, vaginal fluid, organs) of an
infected person.
Transmission
13. The incubation period of the Ebola virus ranges from
2 to 21 days.
symptoms often begin within a few days of
becoming infected, with the sudden onset of high
fever, weakness, muscle pain, headache and sore
throat.
This is quickly followed by more severe symptoms
including vomiting, diarrhea, rash, decreased kidney
and liver functioning, and internal and external
bleeding. Specific laboratory blood tests can confirm
diagnosis.
Symptoms
14. 1. Hosts
•The life cycle of the virus has been explained.
The Ebola virus has so far two known hosts –
primates and Homo sapiens. As explained, the
virus is termed as a level 4 agent, which means
that it is extremely infective and lethal
Pathology
15. 2. Mode of Action
•Ebola is extremely destructive to the host,
which could probably explain the fact why it
has not yet been as successful in
penetrating the human species as AIDS. The
extreme speed at which it spreads through
the body and destroys it, prevents it from
transmitting itself from host to host with a
high rate of success. While AIDS is a silent
stalker, Ebola is a violent, bloody predator
Pathology
16. 3. Affinity for Connective tissue
•Most strains of Ebola attack every part of the
human body with the exception of skeletal muscle
and bone
•The skin develops haemorrhages under itself. Ebola
has a particular affinity for connective tissue, which
is the tissue that holds the internal organs
together. By its action, the virus actually acts on
the collagen (the protein which is a component of
connective tissue) and converts it into a soft mush
and under layers of the skin die.
Pathology
17. 4. Destruction of the Host
•The virus kills a huge amount of tissue and converts it
into a digested slime before it finally kills its host.
•Internal organs slough tissue and even the heart
itself begins to bleed inside itself.
•At the end of the process the host is totally
destroyed in a process called ‘crashing out’ where the
host dies and begins to bleed from every possible
orifice, including the skin pores. This could be viewed
as a mechanism for the virus to ‘seek’ a new host
Pathology
