The document discusses Ebola virus disease (EVD), also known as Ebola hemorrhagic fever. It first appeared in Africa in 1976 and causes severe bleeding and organ failure in humans and nonhuman primates. The virus spreads through direct contact with body fluids of infected individuals or contaminated environments. While there is no approved vaccine or treatment, prevention focuses on isolation of patients, medical staff training in infection control, safe burials, and avoiding contact with high-risk animals like bats that may carry the virus. The document provides details on the virus's pathogenesis, symptoms, subtypes, transmission methods, and the challenges it poses given its rapid multiplication and ability to evade immune responses.

1. Ebola
The Deadly
African Virus
Dr. vibha bhargava

2. •What is ebola &how
does it spread

3. • Ebola virus disease (EVD) or Ebola
hemorrhagic fever (EHF) is a disease of
humans and other primates caused by
an ebolavirus.
• Symptoms start two days to three weeks
after contracting the virus, with a fever, sore
throat, muscle pain and headaches.

4. Ebola Virus Introduction
• First appeared in Africa 1976
• “African Hemorrhagic Fever”
– acute,mostly fatal disease
– causes blood vessel “bursting”
– systemic (all organs/tissues)
– humans and nonhuman primates

5. • Ebola: WHO declares the
epidemic as global emergency
• US health authorities had admitted that
Ebola's spread beyond west Africa was
inevitable. Even medical charity Doctors
Without Borders had warned that the deadly
virus was now "out of control" with more than
60 outbreak hotspots

6. In india
• Health Minister Harsh Vardhan said there
is no reported case of the virus in the
country and the government is taking all
precautions. He said, “As of today, this
moment, there is no Ebola case reported in
India. There is no need to panic.”

7. Ebola Taxonomy
Scientific Classification
Order: Mononegavirales
Family: Filoviridae
Genus: Ebola like viruses
Species: Ebola
Subtypes -5 types
– Ebola-Zaire, Ebola-Sudan,Ebola-Ivory Coast
• disease in humans
– Ebola-Reston
• disease in nonhuman primates
Copyrighted
Dr. Fre:derick A. Murphy, D.V.M., Ph.D. 1976.

8. Filoviridae or “Filoviruses”
• Most mysterious virus group
• Pathogenesis poorly understood
• Ebola
– natural history/reservoirs unknown ,
researchers believe the most likely natural
hosts are fruit bats.
– exist throughout the world
– endemic to Africa
– filamentous ssRNA- (antisense) viruses
Image courtesy of the Centers for Disease Control

9. Ebola Pathogenesis
• Enters Bloodstream
– skin, membranes,open wounds
• Cell Level
– docks with cell membrane
• Viral RNA
– released into cytoplasm
– production new viral proteins/ genetic
material
• New viral genomes
– rapidly coated in protein
– create cores
Copyright: Russell Kightley Media, Australia

10. Ebola Pathogenesis, cont
• Viral cores
– stack up in cell
– migrate to the cell surface
– produce trans-membrane proteins
– push through cell surface
– become enveloped by cell membrane
• ssRNA- Genome Mutations
– capable of rapid mutation
– very adaptable to evade host defenses and environmental change

11. • Ebola is extremely infectious but not extremely contagious. It is infectious,
because an very small amount can cause illness. Laboratory experiments on
nonhuman primates suggest that even a single virus may be enough to trigger
a fatal infection.
• Instead, Ebola could be considered moderately contagious, because the virus
is not transmitted through the air. The most contagious diseases, such as
measles or influenza, virus particles are airborne.

12. • How do people become infected with the virus?
• Ebola is introduced into the human population through close contact with the
blood, secretions, organs or other bodily fluids of infected animals.
In Africa, infection has occurred through the handling of infected
chimpanzees, gorillas, fruit bats, monkeys, forest antelope and porcupines
found ill or dead or in the rainforest.
It is important to reduce contact with high-risk animals (i.e. fruit bats,
monkeys or apes) including not picking up dead animals found lying in the
forest or handling their raw meat.
• Once a person comes into contact with an animal that has Ebola, it can spread
within the community from human to human. Infection occurs from direct
contact (through broken skin or mucous membranes) with the blood, or other
bodily fluids or secretions (stool, urine, saliva, semen) of infected people.
Infection can also occur if broken skin or mucous membranes of a healthy
person come into contact with environments that have become contaminated
with an Ebola patient’s infectious fluids such as soiled clothing, bed linen, or
used needles.

13. tranmission
• Health workers have frequently been exposed to the virus when caring for
Ebola patients. This happens because they are not wearing personal protection
equipment, such as gloves, when caring for the patients. Health care providers
at all levels of the health system -- hospitals, clinics and health posts -- should
be briefed on the nature of the disease and how it is transmitted, and strictly
follow recommended infection control precautions.
• Burial ceremonies in which mourners have direct contact with the body of the
deceased person can also play a role in the transmission of Ebola. Persons who
have died of Ebola must be handled using strong protective clothing and
gloves, and be buried immediately.
• People are infectious as long as their blood and secretions contain the virus.
For this reason, infected patients receive close monitoring from medical
professionals and receive laboratory tests to ensure the virus is no longer
circulating in their systems before they return home.

14. Who is most at risk?
• During an outbreak, those at higher risk of infection are:
• * health workers;
* family members or others in close contact with infected people;
* mourners who have direct contact with the bodies of the deceased as part of
burial ceremonies; and
* hunters in the rain forest who come into contact with dead animals found
lying in the forest.
More research is needed to understand if some groups, such as immuno-compromisaed
people are more susceptiblea than others to contracting the
virus.

16. Why it is so deadly
• Various infectious diseases like tuberculosis, AIDS and dengue have
killed millions of people all over the world but what distinguishes
Ebola from others, is that is highly mysterious..
• It can kill within seven days: Ebola violently multiplies until the
viral particles are amplified to about 100 million viral particles in a
droplet of blood. Further, without resting in a dormant stage the virus
kills the host to find a new one. The fatality rate of the disease is 60
percent.
• There is no vaccine or treatment available: What makes this virus
deadly is the fact that researchers have not been able to find an
effective treatment or preventive technique to combat the virus and the
spread of the disease. The experimental drug Zmapp has shown
promising results but the safety and efficacy of the drug are to be
evaluated. So, as of now, neither do we have an effective form of
therapy nor do we have a vaccine to prevent the disease.

17. • Attacks every part of the human body: Ebola only needs a host cell
that can help it produce multiple copies of itself. What worsens the
condition is the fact that the virus does not need a specific type of cell
to multiply (unlike other deadly diseases). According to studies,
except for skeletal muscles and bones, the virus is known to infect
every part of the human body. Connective tissues, the ones that hold
your internal organs in place, are primary targets of the virus.
• Disrupts your immune system: Viral proteins present on the outer
surface of the Ebola virus are what destroy the immune system. VP35,
one of those proteins, interferes with the production of some important
components of the human immune system, like interferons. Another
protein traps the white blood cells inside the circulatory system by
limiting their movement. As a response to the virus, whatever
molecules the immune cells release are used by the virus to devastate
the vascular system and activate blood clot formation

18. • We don’t know where it came from: First of all, scientists have not
been able to identify the original reservoir of the virus yet. Bats have
been the suspected source but the results are inconclusive. Since a
major part of its life cycle remains a mystery, the threat of its recurring
outbreak will persist.
• We don’t know all the different ways it can spread: The Ebola
virus certainly spreads through direct contact with infectious body
fluids and secretions including blood, semen, stool, mucus, saliva and
sweat. But there is a possibility that it could spread through other
modes, increasing the chances of the disease spreading.
• The virus manipulates your immune system: Once the virus enters
the body, it attacks your immune cells, namely macrophages and
monocytes. The immune cells get fooled and release large amounts
cytokines that instead facilitate the entry of the virus into endothelial
cells easily. These cytokines alarm other immune cells to reach the site
of infection, exposing them to the virus. While the immune system is
still being attacked by the virus, some viral particles that reach the
liver start destroying the liver cells to ensures that cell signals are not
cleared from the bloodstream.

19. • Multiplies rapidly: Once inside the body, the virus’s genetic material
(single-stranded RNA) begins to multiply rapidly into the host cell.
The genetic material is translated to produce viral proteins that form an
outer covering of the viral particles protecting its genetic material.
• Releases hundreds of viruses at a time: Within no time, the infected
cells becomes packed with blocks or crystals of viral particles. They
move towards the cell wall of the infected cell and finally burst the cell
releasing hundreds of new viral particles that travel through the blood,
attacking healthy cells.
• Destabilises the vascular system: When the new virions are on their
way outside the infected host cell, the host cell detaches from its
neighbouring cell and loses it contact with the membrane it is rested
upon. The viral particles ultimately leave the cell destabilised, causing
massive blood loss or hemorrhage.

20. Prevention
After Death-Virus contagious in fluids for days
• • Burial use extreme caution
• – Handling and transport
• – Cultural practices/ religious belief
• – Incinerate all waste!!!!
• – Protective clothing
• – Body sealed in body bag and coffin
• – Sanitation of all equipment before and after
• – Risk for exposure special steps need to be taken
to protect the family and community from illness.

21. Prevention
• No vaccines!
• Patients are isolated
• Medical Staff Training
– western sanitation practices
• intake
• care during stay
• after patient dies
• Infection-control Measures
– complete equipment and area sterilization

22. Treatment
• No Standard Treatment available
• Patients receive supportive therapy
• treating complicating infections
• balancing patient’s fluids and electrolytes
• maintaining oxygen status and blood pressure

23. •Thank you