Klint Hockenberry

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Smallpox (Variola major)
www.mitretek.org
Klint Hockenberry Jenn Savino Julie
Thompson Under advise of Dr. Michael Boyle
Juniata College
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VARIOLA MAJOR THE SMALLPOX VIRUS

• Morphology
• Replication Cycle
• Background of Smallpox
• Description of Disease
• Smallpox vs Chickenpox
• The Vaccine

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Genetic Material and Morphology

• The poxviruses are the most complicated type of
  animal virus.
• Genetic Material Double stranded linear DNA
• Morphology of virion
• Envelope and Surface membrane (green/blue)
• Core (red)
• Lateral bodies (purple)

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Variola major

• Virions invade cell
• Replication via dsDNA and RNA Polymerase
• Replication of genetic material
• Virion assembly
• Release from cell

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Replication Cycle
http//www.rkm.com.au/VIRUS/SMALLPOX
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History of Smallpox

• Raised bumps that appear on the face and body of
  an infected person
• 3,000 years ago in India or Egypt
• Killed as many as 30 of those infected
• Edward Jenner- inoculation with cowpox
• 10-15 million cases of smallpox by 1967 because
  of the vaccine (prior was 50 million cases)
• Eradication

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Forms of Smallpox

• There are two forms of smallpox, variola minor
  and variola major.
• member of the genus Orthopoxvirus
• Other members of this genus include cowpox,
  camelpox, and monkeypox
• Variola major is the most common form of smallpox
  and it is the most severe.

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Mode of Contraction

• Spread through direct contact with infected
  bodily fluids or contaminated objects of those
  who have the disease

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Dont let it spread!

• Patients who developed rash before their
  isolation should try to recount all recent
  contacts
• Medical care givers should wear gloves, caps,
  gowns, and surgical masks
• All contaminated instruments, excretions, fluids
  and other materials should be decontaminated
  chemically, by heat, or incineration

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Symptoms

• 12-14 day incubation period with no symptoms and
  the person is not contagious
• Fever, malaise, head and body aches, sometimes
  vomiting
• RASH!!!

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Distribution of Rash

• Chickenpox occurs over center of body, not arms
  and legs. Not located on soles of hands or feet.
  

• Smallpox is most dense on the face, arms and
  hands, legs and feet. The trunk has fewer pocks
  than the extremities. Common for pocks to be
  located on soles of hands and feet.

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Smallpox vs Chickenpox

• By day 5 the diseases are clearly different
• Rate of rash development- smallpox slower
• Stages of development- smallpox same stage
• Size of lesions- smallpox larger
• Characteristic of lesions- smallpox deep
• Rate of scab formation/falling off- smallpox
  longer

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Smallpox vs Chickenpox (cont.)

• Features that help differentiate between smallpox
  and chickenpox in smallpox, the fever precedes
  the rash by 2 to 4 days the pocks on any part
  of the body are at the same stage of development,
  and they develop slowly the pocks are more
  numerous on the arms and legs than on the body
  the pocks are usually present on the palms and
  soles death following smallpox is not uncommon,
  while in chickenpox death is very rare

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Smallpox vs Chickenpox (cont. 2)
http//www.who.int/emc/diseases/smallpox/slideset/
index.htm
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Smallpox vs Chickenpox (cont. 3)
http//www.who.int/emc/diseases/smallpox/slideset/
index.htm
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Treatment

• Vaccine administered up to 4 days after exposure
  to the virus and before the rash appears
• No effective treatment, only able to manage
  symptoms
• A number of compounds are under investigation as
  chemotherapeutic agents

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Administering the Vaccine

• Given with a bifurcated needle (two-pronged) that
  is dipped into the vaccine solution

http//www.who.int/emc/diseases/smallpox/Historica
l
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Reaction of the Vaccine
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Smallpox Bioterrorist Agent

• Setting the stage
• Characteristics of the weapon Smallpox
• Smallpox weaponization
• Elimination
• Preparation
• Conclusion

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Setting the Stage
Ramses V. 1000bce

• Most lethal virus in history
• WHO resolution eliminates smallpox in 1977
• Mailing of Anthrax spores brings bioterrorism to
  the forefront of public concern

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Characteristics of weaponized smallpox

• Category A agents
• Anthrax, Botulism, Plaque, Smallpox, Tularemia,
  Viral Hemorrhagic Fevers(ebola, marburg)
• Agents are categorized based on ease of
  cultivation, dispersal ability, and deadliness
• Smallpox
• Highest person to person transmission rate
• Susceptibility increased following elimination
• Most feared by public

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Smallpox Weaponization

• WHO resolution results in eradication of virus in
  1977
• Laboratory samples kept only at CDC in Atlanta or
  Moscow facility
• Inspections reveal Soviets development and
  weaponization research
• Soviet defectors reveal frightening truths

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Smallpox Weaponization

• Eradication
• Routine childhood vaccination is no longer
  necessary
• gt50 of present U.S. population is susceptible
• Prior use of smallpox as a weapon in the French
  and Indian War illustrates deadliness

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Elimination

• Heated debate Is elimination of all (including
  laboratory) samples preferrable?
• Pro viewpoint simple elimination of disease
• Con Viewpoint
• Pursuit of further knowledge
• Eliminates only those samples that are
  legitimately acquired
• Possibility of natural reemergence
• Mutations of similar viruses (monkeypox,
  camelpox)
• Frozen corpses

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Preparation

• 1 billion in federal aid to state and local
  health agencies
• Prevention
• Awareness
• Detection
• Three phase vaccination

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Conclusion

• Unquantifiable risk
• Likelihood
• Implications

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Mousepox

• A member of the pox virus family
• Researchers have modified the genome of mousepox
• Inserting Interleuken-4 gene
• More lethal
• Bioterrorism implications

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Superpox Viruses

• For the normal smallpox virus, we have successful
  vaccination strategies
• If smallpox would be modified with IL-4 as
  mousepox, then our vaccinations are useless

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References

• http//www.who.int/emc/diseases/smallpox/History
• http//life.bio2.edu/ICTVdB/00.058.1.01.011.htm
• Broad, William J. 2003, Nov. 1. Bioterror
  Researchers Build a More Lethal Mousepox. New
  York Times Online. lthttp//www.nytimes.com/gt.
  Accessed Nov. 4, 2003.
• http//www.rkm.com.au/VIRUS/SMALLPOX
• www.bt.cdc.gov/agent/smallpox/index.asp