Hemorrhagic Fevers

1
Hemorrhagic Fevers

• With a Concentration on Filoviruses

Simon A Francis Susanna Epstein Medha Goyal
2
History

• Hemorrhagic Fevers
• Definition a severe multi-system syndrome.
• Vascular System Damaged
• Body regulation Impaired
• Accompanied by hemorrhage
• Four families of viruses
• Arenaviruses (Junin Virus)
• Bunyaviruses (Nariovirus )
• Flaviviruses (ie. Yellow Fever)
• Filoviruses (Marburg Ebola)
• CDC Classification BSL-4 Agent

3
History

• Hemorrhagic Fevers (Continued)
• RNA viruses covered in a lipid coating
• Viruses are geographically restricted to areas
  where host species live
• Humans are not natural reservoirs for these
  viruses

4
History

• Filoviruses
• Marburg Virus
• A.K.A. (African Hemorrhagic Fever, Green Monkey
  Disease, Marburg Fever)
• First outbreak (Marburg Germany, 1967)
• laboratory workers infected by monkeys
• Simultaneous outbreak in Hamburg, Germany and
  Belgrade, Yugoslavia (now Serbia)
• 32 human cases
• 31 primary one generation of secondary
  transmission
• 23 of human mortality
• Overall Mortality 23-25

5
History

• Filoviruses (continued)
• Ebola Virus
• Named after a river in the Republic of Congo
  (Formerly Zaire)
• First outbreak (Zaire 1967)
• 318 human cases
• 88 mortality
• Disease spread by close personal contact in
  hospital setting (amplification)
• Fatal in humans and non-human primates
• Four subtypes (80 nm in diameter)
• Ebola-Zaire(990-1086 nm in length ), Ebola-Sudan
  (974-1063 nm in length), Ebola-Ivory Coast,
  Ebola-Reston (disease in non-human primates
  1026-1083 nm in length )

6
History

• Filoviruses (Continued)
• Ebola (Continued)
• Sudan international scientist arrived
• To late to deal with virulent epidemics
• Hospitals closed
• Infected patients quarantined
• Reconstructed data from survivors

7
Outbreaks

• Marburg
• Europe Outbreaks
• 1967
• Hamburg and Marburg, Germany and Belgrade,
  Yugoslavia
• Africa Outbreaks
• 1975
• Johannesburg, South Africa
• 3 died
• 1980
• Western Kenya
• 2 Died (Physician died in Nairobi)
• 1987
• Young man traveling extensively in Kenya
• 1999-2000
• Outbreak in Durba, Republic of Congo
• Cases linked to workers in a gold mine

8
Outbreaks

• Ebola (types named after location)

This diagram was adapted from a WHO publication
accompanied by the following note (edited)
Phylogenic tree showing the evolutionary
relationship of Ebola viruses (courtesy of A.
Sanchez, Centers for Disease Control and
Prevention CDC derived from Georges-Courbet
MC, Sanchez A, Lu CY, et al. Isolation and
phylogenetic characterization of Ebola viruses
causing different outbreaks in Gabon. Emerg
Infect Dis 1997359-62).
9
Year Ebola subtype Country No. of human cases Percentage of deaths among cases Situation
1976 Ebola-Zaire Zaire Democratic Republic of the Congo (DRC) 318 88 Occurred in Yambuku and surrounding area. Disease was spread by close personal contact and by use of contaminated needles and syringes in hospitals/clinics. This outbreak was the first recognition of the disease.
1976 Ebola-Sudan Sudan 284 53 Occurred in Nzara, Maridi and the surrounding area. Disease was spread mainly through close personal contact within hospitals. Many medical care personnel were infected.
1976 Ebola-Sudan England 1 0 Laboratory infection by accidental stick of contaminated needle.
1977 Ebola-Zaire Zaire 1 100 Noted retrospectively in the village of Tandala.
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1979 Ebola-Sudan Sudan 34 65 Occurred in Nzara. Recurrent outbreak at the same site as the 1976 Sudan epidemic.
1989 Ebola-Reston USA 0 0 Ebola-Reston virus was introduced into quarantine facilities in Virginia, Texas, and Pennsylvania by monkeys imported from the Philippines. Four humans developed antibodies to Ebola-Reston virus but did not become ill.
1990 Ebola-Reston USA 0 0 Ebola-Reston virus was introduced once again into quarantine facilities in Virginia, and Texas by monkeys imported from the Philippines. Four humans developed antibodies but did not get sick.
1992 Ebola-Reston Italy 0 0 Ebola-Reston virus was introduced into quarantine facilities in Sienna by monkeys imported from the same export facility in the Philippines that was involved in the episodes in the United States. No humans were infected.
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1994 Ebola-Zaire Gabon 49 59 Occurred in Mékouka and other gold-mining camps deep in the rain forest. Initially thought to be yellow fever identified as Ebola hemorrhagic fever in 1995.
1994 Ebola-Ivory Coast Ivory Coast 1 0 Scientist became ill after conducting an autopsy on a wild chimpanzee in the Tai Forest. The patient was treated in Switzerland.
1995 Ebola-Zaire Democratic Republic of the Congo (formerly Zaire) 315 81 Occurred in Kikwit and surrounding area. Traced to index case-patient who worked in forest adjoining the city. Epidemic spread through families and hospitals.
1996 Ebola-Zaire Gabon 31 68 Occurred in Mayibout area. A chimpanzee found dead in the forest was eaten by people hunting for food. Nineteen people who were involved in the butchery of the animal became ill other cases occurred in family members.
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1996 Ebola-Zaire Gabon 60 75 Occurred in Booué area with transport of patients to Libreville. Index case-patient was a hunter who lived in a forest camp. Disease was spread by close contact with infected persons. A dead chimpanzee found in the forest at the time was determined to be infected.
1996 Ebola-Zaire South Africa 2 50 A medical professional traveled from Gabon to Johannesburg, South Africa, after having treated Ebola virus-infected patients and thus having been exposed to the virus. He was hospitalized, and a nurse who took care of him became infected and died.
1996 Ebola-Reston USA 0 0 Ebola-Reston virus was introduced into a quarantine facility in Texas by monkeys imported from the Philippines. No human infections were identified.
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1996 Ebola-Reston Philippines 0 0 Ebola-Reston virus was identified in a monkey export facility in the Philippines. No human infections were identified.
2000-2001 Ebola-Sudan Uganda 425 53 Occurred in Gulu, Masindi, and Mbarara districts of Uganda. The three most important risks associated with Ebola virus infection were attending funerals of Ebola hemorrhagic fever case-patients, having contact with case-patients in one's family, and providing medical care to Ebola case-patients without using adequate personal protective measures.
2001-2002 Ebola-Zaire Gabon and The Republic of the Congo 122 79 Outbreak occurred over the border of Gabon and the Republic of the Congo. Additional information is currently available on the WHO website.
14
New York Times

• February 15, 2003
• World Briefing Africa
• CONGO REPUBLIC EBOLA TOLL REACHES 51 The death
  toll from a suspected outbreak of the deadly
  Ebola virus in Congo Republic has crept up to 51,
  and people have begun fleeing into dense forest
  to escape what some believe to be an evil spell.
  The authorities have tried to impose tight
  restrictions on movement in the hope of
  preventing the spread of the outbreak, the second
  reported in little over a year in the country's
  remote northwest. It is thought to have been
  caused by the consumption of infected monkey
  meat.    (Reuters)

15
Transmission

• Ebola Virus
• No carrier state (reservoir Unknown)
• Researchers Hypothesize that it is Zoonotic
• Unpopular theory that plant may be the reservoir
  of the virus
• Human to Human Transmission through contact of
  contaminated secretions.
• Ebola-Reston
• Occurred in the U.S (Reston, VA)
• Occurred in African Green Monkeys
• Why only to non-human primates?
• Four scientist found to have antibody for the
  disease
• Circumstantial Evidence of airborne transmission
• Spread within and between rooms (national center
  for Infectious Diseases)
• Marburg Virus
• Transmission from animal host unknown
• Human to Human (Close Contact and change of
  fluids highly suspect source of transmission)

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Reservoir

• Not known
• May be
• A rare species
• One that usually does not contact clinical host
• If contact is made the virus may not be easily
  transmitted
• Hypothesize
• Bats
• Plants

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Filoviruses General Facts

• Replication
• Not fully understood. Created by budding of the
  surface of their host cells (Susanna)
• Structure
• Pleomorphic Long sometimes branched filament
  shaped like a 6, U or a circle.
• Each Virion contains one molecule of single
  stranded, negative sense RNA (Susanna)
• Symptoms of Ebola and Marburg (Medha)

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INCUBATION DEATH PERIODS

• Ebola Incubation at 2 21 Days
• Marburg Incubation 3-9 days
• VHF (in general) - Death Between 7 16 Days
• Ebola Death Ensues as Early as 2 Days after
  expression of symptoms

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Morphology and Structure

• Filamentous or Bacillus form
• Vary greatly in length (up to 14000 nm)
• Mean Unit Length
• Marburg- 860 nm
• Ebola- 1200 nm
• Uniform diameter of 80 nm

23

• Filovirus
• Composed of
• Ribonucleoprotein complex (nucleocapsid)
• Matrix
• Envelope studded with peplomers (10 nm long)

24
Filovirus Genome

• Nonsegmented, negative-strand RNA
• Filovirus Genome 19 kb
• 7 Genes
• Nucleotide and amino acid differences b/w
• Marburg and Ebola 55
• Ebola 37 to 41
• Overlaps
• 1 in Marburg genome
• VP30 to VP24
• 2 in Ebola genome-
• VP35 to VP40 GP to VP30

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• Glycoprotein Gene
• Marburg- GP gene encodes 1 product
• 1 open reading frame (0)
• Ebola- GP gene encodes 2 products
• 2 open reading frames (0 -1)
• connected by the insertion of 1 additional A
• at a series of 7 Us on the genomic RNA

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• The 7 sequentially arranged genes are transcribed
  into
• Ebola - 8 major mRNAs
• (7 structural proteins and 1 nonstructural
  protein)
• Marburg 7 major mRNAs
• (7 structural proteins)

27
Filovirus Proteins

• Ebola and Marburg
• encode 7 structural proteins
• Ebola
• encodes 1 nonstructural protein
• Two Main Categories
• Associated with the nucleocapsid
• transcription and replication of viral genome
• Associated with the envelope
• assembly of virus
• receptor binding and virus entry

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• Ribonucleocapsid Proteins
• 1. Nucleoprotein (NP) Gene 1
• 2. Viral Protein 35 (VP35) Gene 2
• 3. Viral Protein 30 (VP30) Gene 5
• 4. Polymerase L Gene 7
• Matrix Proteins
• 5. Viral Protein 40 (VP40) Gene 3
• 6. Viral Protein 24 (VP24) Gene 6
• Membrane Protein
• 7. Glycoproteins (GP) Gene 4
• Secreted Protein
• 8. Secretory Glycoprotein (sGP) Gene 4

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• Nucleoprotein
• Primary structural protein associated with the
  nucleocapsid
• Hydrophobic N-terminal half
• Binds genomic RNA
• Hydrophilic C-terminal half
• (Variable b/w Marburg and Ebola)
• Interacts with matrix proteins

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• VP30- Minor structural protein associated with
  the nucleocapsid
• Polymerase L- Transcription and Replication
• (largest and least abundant protein)
• VP35- Cofactor in transcription and Replication
• (Cofactor in polymerase complex)
• VP40- Matrix protein
• Virus assembly and budding
• Forms hexamers when it contacts the plasma
  membrane which confers added stability during
  assemebly.
• (most abundant protein)
• VP24- Minor Matrix Protein
• Possibly uncoats virus during infection

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Expression of Glycoprotein

• Transcriptional RNA Editing (occurs only in
  Ebola)
• At a series of 7 Us on the genomic RNA template
• insert a non-template-coded adenosine
• 20 of GP mRNA is edited
• GP with 680 amino acids
• 80 of GP mRNA is not edited
• sGP with 370 amino acids

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GP (Structural)

• Formation of GP1-GP2 Heterodimer
• In the trans-Golgi, the precursor molecule (GP0)
  is post-translationally cleaved by furin at
  yielding a heterodimer, (GP1-GP2)
• Furin cleavage site (Arg-Arg-X-Arg/LYS-Arg)
• (Marburg, cleavage site is more toward
  N-terminus)
• Heterodimer is linked together by one disulfide
  bond, a cysteine bridge

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• GP1 Molecule
• C-terminus hydrophilic, highly glycosylated
• Sequences for receptor recognition and binding
• N-terminus hydrophobic
• Connects GP1 to GP2 by a disulfide bond
• GP2 Molecule
• Fusion peptide near near its N-terminus
• Capable of inserting itself in plasma membranes
• Believed to mediate the fusion of the host and
  virus membranes
• Functions of GP
• Forms the Virion Peplomers (Surface Spikes)
• Trimers of the GP1-GP2 Heterodimer,
• probably assembled in the ER
• Mediates viral entry
• by receptor binding and membrane fusion

36
sGP (non-structural)

• Formation and Structure
• Homodimer
• Synthesized from GP mRNA using the conventional
  ORF
• Produced from a precursor molecule cleaved by
  furin near the C-terminus, Precursor molecule ?
  SGP and Delta Peptide
• Homodimer is linked in anti-parallel orientation
  by 2 disulfide bonds between the 1st and 6th
  cysteines on separate molecules

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Virus Entry and Replicationin Host Cells

• Viral surface spikes recognize and bind surface
  receptors of host
• Virus enters cell via endocytosis
• Release of nucleocapsid into cytoplasm
• Transcription
• viral RNA ? polyadenylated, monocistronic mRNA
• Translation and buildup of viral proteins,
  primarily NP
• Budding and release of viruses
• Host Cell dies
• intracytoplasmic vesiculation, mitochondrial
  swelling,
• organelle breakdown

39
Molecules mediating filovirus entry

• Marburg
• Asialoglycoprotein Receptor
• (Found exclusively in hepatocytes)
• Recognizes glycoproteins displaying N-linked
  sugar chains with terminal galactose residues
• Ebola
• Integrins
• N-glycosylated transmembrane cell surface
  receptors
• Ebola and Marburg
• Human folate receptor-?
• Co-factor expressed on cell-surface

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Reverse Transcription System

• Volchkov et al. contructed 2 recombinant EBOV
  clones
• 1. pFL-EBOVe
• antigenomic cDNA clone with authentic editing
  site
• 2. pFL-EBOVe-
• antigenomic cDNA clone with mutated editing site
• Eliminated editing site using site-directed
  mutagenesis
• Editing site in middle of GP gene AAAAAAA
• EBOV polyadenylation signal ATTAAGAAAAAA
• AAAAAAA ? AAGAAGAA

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Observations

• 1. Both pFL-EBOVe and pFL-EBOVe-
• Showed typical filovirus structure
• Possessed similar infectivity and virus
  production
• 2. Visible Cytopathic Effects
• pFL-EBOVe 4-6 days after infection
• But there was still an intact monolayer at day 8
  
• pFL-EBOVe- 3-4 days after infection
• 5-6 days after infection, cell rounding was
  complete

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• 3. Differences in expression of the GP gene
• Wild Type 1/5 GP, 4/5 sGP
• pFL-EBOVe - 1/5 GP, 4/5 sGP
• pFL-EBOVe- - no sGP expression,
• increase in GP expression
• The increase in GP expression by pFL-EBOVe-
• no simultaneous increase in virus release
• most of GP synthesized were immature precursors
• -with sugar side chains high in mannose
• -sensitive to treatment with endoglycosidase H
• -GP transport was arrested in ER or early Golgi

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Conclusions

• No Transcriptional RNA Editing
• Over-expression of GP
• Exhausts Cell Host Machinery
• Eventual Cell Death
• So GP expression and cytotoxicity can be
  down-regulated by virus through transcriptional
  RNA editing and sGP expression

47
Pathogenesis of EBOV Infection

• sGP
• 1. Inhibits early activation of neutrophils
• -Binds to neutrophils via CD16b cell surface
  receptor
• -CD16b activates neutrophils via lateral
  membrane interaction with CR3
• 2. Adsorbs neutralizing antibodies
• GP
• 1. Specific region of GP induces cytotoxic
  effects in endothelial cells
• -Rapid release of vasoactive agents from
  infected cells
• -Induces cell rounding and detachment from
  extracellular matices
• -Increases cell membrane premeability

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• 2. Proteolytic activation of GP0 precursor via
  cleavage
• -EBO-Z GP cleaved by furin
• -Prerequisite for fusion between viral envelope
  and host cell membrane
• -Enables virus to replicate in host ?systematic
  infection
• 3. Two sequences contribute to evasion of host
  immunity
• -Possible immunosuppressive sequence in GP2
  molecule
• -Amino acid sequence at amino terminus
  suppresses lymphocyte mitogen-stimulated
  proliferation in vitro

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• Destruction of the Immune System
• 1. Infects mononuclear phagocytes and
  fibroblastic reticular system (associated with
  lymph nodes)
• - Failure of early T-cell activation
• -Disrupts antigen trafficking and cytokine
  production
• -Extensive apoptosis of blood leukocytes
• -Lymphopenia (reduction in lymphocyte ) and
  severe damage to lymphoid tissue
• 2. Macrophages and circulating monocytes help
  transmit virus to other tissues

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• 3. VP35 protein Type 1 IFN Antagonist
• -Combats the host interferon response
• possibly enhancing the replicative ability of
  the virus

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Key to Surviving Ebola

• French National Institute- Early Immune Response
• 1996 Two large outbreaks in Gabon
• Compared immune responses
• Survived
• -IgG response against viruss protein coat early
  on
• -Cleared circulating antigen
• -Activated cytotoxic T-cells
• Died
• -No IgG response
• -Barely detectable levels of IgM

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Pathology of Marburg and Ebola

• EARLY STAGE
• Striking lesions usually in liver, spleen and
  kidney
• Necrosis prominent in liver, lymph tissue, and
  spleen
• little inflammatory response
• Viral particles invade phagocytic cells

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Pathology of Marburg and Ebola

• LATE STAGE
• Liver and spleen become enlarged with excess
  blood
• Hemorrhage in the gastrointestinal tract,
  pleural, pericardial and peritoneal spaces and
  into the renal tubules with deposition of fibrin
• Abnormalities in coagulation parameters suggest
  that disseminated intravascular coagulation is a
  terminal event.
• There is usually also profound leukopenia in
  association with bacteremia.

Example of cervical tissues with severely
enlarged and hemorrhagic lymph nodes from a
laboratory Rhesus monkey.
54
Differential Diagnosis

• Myalgia
• Bradychardia
• Desquamation
• Loss of apetite

• High Fever
• Severe prostration
• Diffuse maculopapular rash
• Bleeding

55
OTHER DIAGNOSTIC CRITERIA

• Coagulation Studies
• Serologic Study
• Leukopenia (Low White Blood Cell Count)
• Thrombocytopenia (Low Platelet Count)
• Low Electrolytes
• lymphopenia followed by neutrophilia

56
DIAGNOSTIC TESTS FOR EBOLA

• ELISA (Enzyme-Linked Immunosorbent Assay)
• Cant differentiate Ebola strains with electron
  microscope
• Indirect fluorescent antibody test (IFAT)
• Western blot analysis
• Radioimmunoprecipitation assay
• skin biopsies

57
ELISA

• Purified, inactivated filovirus antigens
  pre-coated onto an ELISA plate

• If the patient has filovirus, serum contains
  antibodies to the filovirus antigens, and those
  antibodies will bind to the antigens on the
  plate. Test can be specific to IgM or IgG.

• Anti-human Ig coupled to Chromogen enzyme binds
  IgM or IgG.

• Color change indicates positive test

58
Clinical Course

• 2-21 Day incubation time
• 50-90 Mortality
• Variability of clinical presentations complicate
  early detection and management
• Non-specific prodrome typically lasts lt 1 week
• 10 to 12 days after the onset of disease, the
  sustained fever may break, with improvement and
  eventual recovery of the patient.
• 1-2 weeks after onset of symptoms Death often
  preceded by hemorrhagic diathesis, shock,
  multi-organ system failure

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A Word From the Experts
60
On Scene Footage
61
Transmission

• Direct contact with the blood, secretions, organs
  or semen of infected persons
• study of risk factors among family members in
  Kikwit. 27 surviving members were interviewed.
  Determined that those who had direct contact or
  who were exposed during late hospital phase were
  at very high risk. Those who had no physical
  contact with infected members remained
  uninfected.
• Transmission through semen occurs up to 80 days
  after clinical recovery.
• Handling ill or dead infected people or
  chimpanzees
• Health care workers have frequently been infected
  while attending patients- Kikwit outbreak.
• Neonatal
• Droplets or small filovirus particle aerosols
  confirmed in alveoli of monkeys during Reston
  outbreak.

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Current Therapy

• Essentially supportive and directed toward
  ensuring adequate tissue delivery of oxygen,
  nutritional support, and hydration.
• Hemorrhage is managed by replacement of blood,
  platelets, and clotting factors
• Passive transfer of human antibodies has remained
  inconclusive in its benefit to Marburg and Ebola.
• Ribavirin is a synthetic nucleoside analog that
  is of use in treating Lassa fever and Arenavirus,
  but there is unfortunately no benefit in Ebola
  virus infection.

63
Prophylaxis

• Study shows
• hyperimmune globulin effective in protecting
  experimentally infected baboons if administered
  at the same time as virus, the treatment was
  ineffective if delayed for 3 days. Hyperimmune
  globulin should, however, be considered for
  prophylactic use in laboratory or nosocomial
  accidents although humans may require antibodies
  with higher specificity.
• Inconclusive evidence- whether whole blood
  transfusion from convalescent patients are
  effective.
• Kikwit epidemic- 8 convalescent patients were
  given blood transfusions. 7/8 survived.
  Administered late, patients had better prognosis
  for survival, lack of controls.

64
Comorbidity Pregnancy

• Illness from Ebola is generally more severe in
  pregnant women, with more serious hemorrhagic and
  neurologic complications
• Case fatality rate of pregnant women was 95.5
  versus 77 in nonpregnant infected persons
• Spontaneous abortion is frequent, with fetal
  losses reported to be as high as 2366
• All infants born to mothers with EHF ultimately
  died within 19 days of delivery

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Potential Vaccines

• Dutch biotechnology company, Crucell, is to
  collaborate with the US National Institute of
  Allergy and Infectious Diseases (NIAID) to
  develop the first vaccine against the Ebola
  virus.
• The new vaccine uses DNA encoding three Ebola
  glycoproteins and one nucleoprotein, followed by
  a boost with a replication-defective adenovirus
  expressing Ebola antigens (Nature 408, 605
  2000). It is the first vaccine to generate
  protective immunity against Ebola in non-human
  primates.
• Scientists at the US Army Medical Research
  Institute of Infectious Diseases report a simple
  method for generating Ebola viruslike particles.
  (JAMA March 2002)
• A researcher has discovered a link between HIV
  and Ebola virus Both viruses use the same method
  to spread through the human body. Aids Alert -
  01-Feb-2002

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Vaccine Contd.

• Reverse genetics vs Forward genetics
• genetics that is concerned with genetic material
  whose nucleotide sequence is known -analyzes its
  contribution to the phenotype of the organism by
  varying the nucleotide sequence
• -observe the results of such variation in the
  living organism, in living cells, or in vitro on
  macromolecules

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Ebola from scratch

• In January 2002 scientists reported making Ebola
  using "reverse genetics".
• They took the virus's genome plus pieces of DNA
  coding for the key viral proteins and added them
  to cells. These proteins then kick start the
  replication process.
• Good News DNA is more stable and easily
  manipulated. Method provides in-depth
  understanding of viral mechanism of action that
  may lead to a vaccine/cure.
• Bad News People acquire ability to synthesize
  Ebola

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Weaponization

• History of Ebola Weaponization
• Soko Asafra head of Aum Shinrikyo cult 1992
• Russians

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THE APRIL of 1988 USTINOV INCIDENT

• Ustinov conducted basic research on the Marbur
  Virus studying its potential as a weapon
• Long term goal To see if Marburg Virus could be
  loaded into special biological warheads on the
  Soviets MIRV missiles.
• MIRV has multiple warheads which are directed at
  different targets
• They at the time where designed to be loaded with
  strategic/operational smallpox virus, black
  death, and anthrax.
• Variant U was born

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Weaponization

• Fall 1991 Marburg Variant U becomes a strategic
  operational Bioweapon
• Russians loaded virus into 10 separate
  cone-shaped warheads on the MIRV.
• Cooling system inside each warhead keeps the
  virus alive during heat of atmosphere.
• Biowarheads parachuted over the target city
• Certain altitude they break apart
• Each warhead burst a spray of more than a hundred
  oval bomblets each the size of a small cantaloupe
• Cantaloupes fly and then split again in an
  overlapping manner releasing a haze of
  bio-particles that quickly become invisible.

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Challenges

• Finding the Reservoir
• Need to know more about Transmission
• From animal to man
• Ways of putting it into food
• Aerosolization
• Possible
• Stable Base needed (difficult)

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Why Use Filoviruses as Bioweapon

• Filoviruses (Ebola in particular)
• Rates of fatality
• Deaths
• Terror of dying
• Ignorance of the general public
• Think that they can die by being in same room
  with person
• Much not known by general physicians and scientist

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Genetic Engineering

• At Marburg and Ebola conference talk about
  creation of genetically engineered Ebola virus
• Volchkov of Claude Bernard University in France
  and Institute for Virology in Marburg
• Powerful Molecular tool to analyze how these
  viruses cause disease.
• Constructed DNA Molecule (Complimentary
  Nucleotide sequence to Ebola)
• Introduced complementary sequence in cultured
  cell lines with genes coding for 4 key Ebola
  proteins
• Cells proceeded to make new Ebola RNA
• Resulting in fully infectious when transferred to
  new cell lines
• Military Definition The creation of genetically
  altered viruses and/or bacteria to enhance their
  power as weapons
• Reasons for use in Filoviruses
• To make the virus stronger
• Mixtures
• Ebolapox
• Smallpox is an extremely lethal virus highly
  contagious in the air.

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OPERATIONAL EFFECTIVENESS OF EBOLAPOX

• Produces a form of smallpox called blackpox
• Blackpox is the most severe type of Smallpox.
• In BLACKPOX infection the skin does not develop
  blisters
• Instead the skin becomes dark all over
• Blood vessels leak, resulting in severe internal
  hemorrhaging
• Therefore, EBOLAPOX would not only provide the
  Terrorist with the hemorrhages and high mortality
  rate of the Ebola virus, but in addition as an
  added bonus would incorporate into its
  operational effectiveness the incredibly high
  contagiousness of Smallpox

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Ways to protect against Ebola

• Government
• Biosafety Department
• CDC other agencies
• Debriefing of experts
• Public health education
• Weaponeers
• Public policy and preventative measures (Medha)

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PREVENTING VHF EPIDEMIC

• Hospitalization and Isolation of Patients
• Quarantine Areas if Necessary
• Protective Measures (Gloves, Gowns, Face Shields,
  Masks, Eye Protection)
• Disinfect Bedding, Utensils, Excreta (Heat or
  Chemicals)
• Burn Used Articles

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Isolation Criteria
Decision-making for isolation is based upon 4
main factors 1. Potential harm to life 2.
Potential harm to critical systems 3.
Potential harm to property 4.Topography
meteorological considerations
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Isolation Precautions

• Direct Contact with infected blood, body fluids
  to be avoided.
• Airborne transmission rare, but cannot be
  conclusively excluded- negative pressure room and
  HEPA respirator.
• Laboratory Precautions- BSL 4
• Personal Protective Equipment
• Post-Mortem Practices (Kikwit
• And Uganda)

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Prevention and Control

• Reservoir remains unknown
• Clarify roles of GP, sGP, and
• other viral proteins.
• Multivalent vaccine needed
• (4 strains of Ebola)
• Health infrastructures strengthened
• especially in Africa
• Surveillance improved to prevent potential spread
  of an epidemic.