Ebola Virus
Hemorrhagic Fever
Outbreaks

1976- First Major
Outbreak (ZEBOV)
 1976- Sudan
(SEBOV)
 Occur Sporadically
 www.cdc.gov for more
information
Where does Ebola hide?
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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
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 world’s 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.
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 don’t 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).
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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)
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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
Epidemiology

Ebola Hemorrhagic Fever was first found in 1976
 It struck two countries within that year
 a. Sudan – in a town called N’zara
 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.
Transmission

contracted through contact of any infected
individual’s body fluids
Ebola HF prevention
poster used in Kikwit
outbreak.
Controlling the spread of Ebola

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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
Ebola Subtypes

Ebola-Zaire
(ZEBOV)
 Ebola-Sudan
(SEBOV)
 Ebola Ivory-Coast
(ICEBOV)
 Ebola-Reston
(REBOV)
MOLECULAR STRUCTURE

Characterization of the virus
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Order: Mononegavirales
Family: Filoviridae
Genus: Ebolavirus
Species: Ebola-Zaire, Ebola-Sudan, Ebola-Cote d-Ivoire, EbolaReston
Morphology under electron microscope
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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

Structure of Ebola genome and proteins
– Transcribed into 8 sub-genomic mRNA proteins: 7
structural and 1 nonstructural
– 7 structural proteins:
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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
Proteins
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 world’s
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.
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.