Biological Agents of Warfare and Terrorism

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Biological Agents of Warfare and Terrorism

• Lecture Week 12
• Medical Microbiology SBM 2044

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Deliberately Emerging Infections

• These microbes have been developed by man for
  nefarious use
• Deliberate refers to
• naturally occurring microbial agents such as
  anthrax
• bioengineered microorganisms such as those
  created by the insertion of genetic virulence
  factors that produce or exacerbate disease

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Biological weapons

• Bioterrorism the malevolent use of bacteria,
  viruses or toxins against humans, animals or
  plants in an attempt to cause harm and to create
  fear
• Biological weapons are inexpensive
• Nuclear and chemical weapons are 800-600 times
  more costly to develop
• Produce fear and panic ? overwhelm health care
  resources and destabilise government
• Attention and understanding (of treatment) on
  bioterrorism is important to avoid this imminent
  threat to national security

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History

• Black Death of the 14th century
• When the Tartars catapulted plague victims over
  the unassailable city walls in Kaffa
• Killed 50 million of people, that is almost half
  of the Europe at that time
• 1763, British troops in America used
  smallpox-infected blankets against the American
  Indians
• 1984, an attempt to affect election in a small
  Oregon town, the Rajneeshees cult poisoned 10
  restaurant salad bars with Salmonella typhimurium
  and sickened more than 700 people

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Tentative chronology of the initial spread of
plague in the mid-14th century
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Plague

• In the Islamic world, the Black Death had a
  particularly devastating effect militarily and
  economically. The rapid spread of the Plague
  through armies affected the outcome of several
  minor wars throughout the Islamic world. Even the
  strong Mamluk warriors in Egypt was sufficiently
  devastated by the Plague that the decline in its
  military capabilities was a significant factor in
  its demise and eventual defeat to the Ottoman
  Empire in the early 16th century.
• Also, the Muslim historian Ibn Khaldun, lost his
  parents to the Black Death.

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The plague was accompanied by chaos and panic.
People could not understand for what they were
being punished.
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Plague

• Also known as the Black Death, began in 1346 and
  wiped out ½ of Europe
• Pandemics of plague have ceased with the advent
  of antibiotics and improved rodent control
• But the outbreaks still occur
• Yersinia pestis as a biological weapon
• is relatively stable in the environment
• 100-500 organisms are enough to cause infection

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Zoonotic infection of rodents
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Anthrax

• Caused by ________ that forms stable endospores
  when nutrients are limited
• The spores is the infectious particle
• naturally stable, resistant to destruction
  (heat, dessication)
• the weaponization of anthrax spores by drying
  and milling generates a unit spores size
• Symptoms
• Illness begins 1 to 6 days after exposure
• Flulike fever, myalgia, malaise
• Haemorrhagic mediastinitis (apparent on
  radiograph)
• Shortness of breath, strident cough, chills
• Death as the bacilli spread throughout the body
  in high numbers

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Treatment for anthrax

• Antibiotics, to be administered prophylactically
  after spore exposure
• Bacillus anthracis is susceptible to
  fluoroquinolones, tetracyclines, most other
  antibiotics
• Anthrax vaccine for military personnel,
  researchers

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Smallpox

• 1977 in Somalia, the last naturally occurring
  case of smallpox
• 1980 WHO certified the world free of smallpox
• Infection could spread rapidly from
  person-to-person, by aerosol release
• Prevention vaccination with live vaccinia virus

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Infectious period starts at the onset of
fever Within 2-4 days of fever onset, patient
will develop a maculopapular rash on the mucosa
of the mouth, pharynx and arms. Then spreads to
the trunk and legs
Figure shows pocks or sores which marked faces
and limbs of smallpox patients.
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Conclusion

• Terrorists might favour biological weapons than
  nuclear or chemical ones, for mass destruction
  because
• bioweapons are easy to obtain
• bioweapons are cheap to produce in large
  quantities
• bioweapons are highly effective in creating
  human morbidity and panic

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