Ebola Virus

1
Ebola Virus

• Hemorrhagic Fever

2
Outbreaks

• 1976- First Major Outbreak (ZEBOV)
• 1976- Sudan (SEBOV)
• Occur Sporadically
• www.cdc.gov for more information

3
Where does Ebola hide?

• 2002- Fruit Bats
• Antibodies against Ebola
• Ebola Gene sequences in liver and spleen
• Fruit bats do not show any symptoms
• Best candidate to be the reservoir
• More research needs to be done

4
Geography

• The link between human infection by the Ebola
  virus and their proximity to primates is clear.
• -Outbreaks occurred in countries that house
  80 percent of the worlds remaining wild gorilla
  and chimpanzee populations.
• - The outbreaks coincided with the outbreaks
  in wild animals.
• - The same distinct viral strains were
  isolated in animal carcasses and in the bodies of
  those who handled those carcasses.
• - These outbreaks were preceded by an
  abnormally large death in wild Gorilla
  populations.

5
Clinical Observations

• Incubation period 2-21 days
  
• Stage I (unspecific)
• -Extreme asthenia (body weakness)
• -diarrhea, nausea and vomiting, anorexia
• abdominal pain
• - headaches
• - arthralgia (neuralgic pain in joints)
• - myalgia (muscular pain or tenderness),
  back pain
• - mucosal redness of the oral cavity,
  dysphagia (difficulty in swallowing)
• - conjunctivitis.
• - rash all over body except in face
• If the patients dont recover gradually at
  this point, there is a high probability that the
  disease will progress to the second phase,
  resulting in complications which eventually lead
  to death (Mupapa et al., 1999).

6

• Stage II (Specific)
• - Hemorrhage
• - neuropsychiatric abnormalities
• - anuria (the absence of urine formation)
• - hiccups
• - tachypnea (rapid breathing).
• Patients who progressed to phase two EHF
  almost always die. (Ndambi et al., 1999)
• Late Complications
• -Arthralgia
• - ocular diseases (ocular pain, photophobia
  and hyperlacrimation)
• - hearing loss
• - unilateral orchitis( inflammation of one or
  both of the testes)
• These conditions are usually relieved with
  the treatment of 1 atropine and steroids

7
Epidemiology

•  Ebola Hemorrhagic Fever was first found in 1976
• It struck two countries within that year
• a.  Sudan in a town called Nzara
• b.  Zaire, now known as the Democratic Republic
  of Congo
•   In these two instances the mortality rate was
  between
• 50 90
• Following those epidemics, Ebola hit Africa in
  many other instances the worst yet being in the
  year 2000 when it struck Uganda infecting more
  than 400 people.

8
Transmission

• contracted through contact of any infected
  individuals body fluids

Ebola HF prevention poster used in Kikwit
outbreak.
9
Controlling the spread of Ebola

• a. Hospitals must follow precautionary methods,
  such as 
• 1.      wearing gloves
• 2.      isolating infected individuals
• 3.      practicing nurse barrier techniques
• 4.      proper sterilization and disposal of
  all equipment
• b.  Burials must be done correctly
• 1.      no washing or touching carcass
• 2.      put into body bags and bury outside
  city
• c. Report any questionable illness to
  officials                   

10
Ebola Subtypes

• Ebola-Zaire
• (ZEBOV)
• Ebola-Sudan (SEBOV)
• Ebola Ivory-Coast (ICEBOV)
• Ebola-Reston (REBOV)

11
MOLECULAR STRUCTURE

• Characterization of the virus
• Order Mononegavirales
• Family Filoviridae
• Genus Ebolavirus
• Species Ebola-Zaire, Ebola-Sudan, Ebola-Cote
  d-Ivoire, Ebola-Reston
• Morphology under electron microscope
• filamentous, enveloped RNA virus
• approx. 19 kb in length (1 kb 1000 RNA
• bases/nucleotides) or 60-80 nm in diameter
• single-stranded, linear, non-segmented
• negative-sense RNA (encoded in a 3 to 5
  direction)
• appears to have spikes due to glycoprotein on
• outside membrane

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• Structure of Ebola genome and proteins
• Transcribed into 8 sub-genomic mRNA proteins 7
  structural and 1 nonstructural
• 7 structural proteins
• nucleoprotein (NP)
• 4 viral/virion proteins (VP35, VP40, VP30, VP24)
• glycoprotein (GP)
• RNA-dependent RNA polymerase (L protein)
• NP, VP35, VP30, L protein required for
  transcription replication
• VP40, GP, VP24 associated with the membrane

13
Proteins
14
Ethics

• Biogeograophical Ethics is defined as motivation
  based on ideas of right and wrong when dealing
  with the geographical distribution of animals and
  plants.
• This concept of can be used to explain the
  worlds shockingly small response to the Ebola
  Virus.
• Because there was little travel to that region by
  people of more developed countries, there was not
  much economic drive for a vaccine, treatment, and
  aid in prevention.

15
Bioterrorism

• Since the September 11 bombings in the United
  States, the locality of this virus has become
  less isolated as the threat of bioterrorism looms
  large.
• The Ebola virus is now on the A list for
  hopeful vaccination development.
• Experiments have even been formed to show how
  Ebola can be used as a bioterror agent.