Bioterrorism and Natural Outbreaks

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Bioterrorism and Natural Outbreaks
Ian Britton - FreeFoto.com
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What is bioterrorism?
The intentional or threatened use of viruses,
bacteria, fungi, or toxins from living organisms
to produce death or disease in humans, animals,
or plants.
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What is a Natural Outbreak?
A disease outbreak is the occurrence of disease
cases in excess of normal expectancy. The number
of cases varies according to the disease-causing
agent, and the size and type of previous and
existing exposure to the agent.
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When does a Natural Outbreak become a
Bioterrorist Attack?
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Natural Disease vs Bioterrorism

• Recent endemic exposure
• Recent travel to endemic area
• Sporadic, infrequent cases
• Multiple cases associated with exposure to the
  same food product or water source

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Natural Disease vs Bioterrorism

• No known endemic exposure
• Point source in urban, crowded setting
• Cluster of severe and fatal illness
• Cases that dont respond to recommended
  antibiotic treatment

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Human Salmonella Enteritidis Associated with
Shell Eggs

• September 7, 2010, a total of 2,612 illnesses
  reported
• 1,519 illnesses associated with outbreak
• 11 states
• 29 restaurants or event clusters
• 1 egg supplier in 15 of these 29 restaurants or
  event clusters

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Why Biological Attacks?

• Easy to obtain
• Inexpensive to produce
• Environmental stability
• Aerosol distribution
• Delayed recognition/response
• Perpetrators escape easily
• Susceptible population

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The use of biological weapons through history.

• 400 B.C. Archers dipped arrows into the manure,
  blood and rotting bodies.
• 14th Century Bodies of bubonic plague victims
  were catapulted over the walls of the city of
  Kaffa.
• 15th Century Spanish contaminated French wine
  with the blood of leprosy victims.
• 17th Century A Polish General put saliva from
  rabid dogs into hollow artillery spheres.
• 18th Century Smallpox blankets were given to
  American Indians.

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U.S. Biological Warfare Program

• Geneva Protocol developed in 1925
• prohibits the use of biological and chemical
  agents during warfare
• U.S. offensive program in 1942-1969
• research program tested the use of anthrax,
  botulism, plague, tularemia, Q fever, Venezuelan
  equine encephalitis virus, brucellosis and
  Staphylococcal enterotoxin B.
• U.S. defensive program in 1969
• offensive biological weapons production
  terminated in the US and all stockpiles of
  bioweapons destroyed
• Biological Weapons Convention in 1972
• Banned the possession of biological agents except
  for defensive research. After signing the
  document, the Soviet Union soon began an
  offensive weapons program.
• Geneva Convention Ratified in 1975

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History of Biological Agent Use/Possession in the
U.S.
1972
College students produced 30-40 kg of Salmonella
typhi with plans to release it into the water
supplies of major Midwestern cities.
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History of Biological Agent Use/Possession in the
U.S.
1984
Members of the Rajneesh cult sprayed Salmonella
on eight local salad bars in Oregon in an attempt
to influence a local election. They caused 715
cases of illness, but didnt alter the election
results.
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History of Biological Agent Use/Possession in the
U.S.
1992
Members of the Patriots Council plotted to kill
law enforcement officers using ricin placed on
the door knobs of their vehicles. The plot failed
because an informant notified authorities, and
the conspirators were arrested.
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History of Biological Agent Use/Possession in the
U.S.
1996
A disgruntled med tech brought doughnuts spiked
with Shigella for her co-workers coffee break.
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History of Biological Agent Use/Possession in the
U.S.
2001

• Multiple anthrax attacks
• 22 cases ( 1 lab-acquired case)
• 11 inhalational cases
• 11 skin cases
• 5 deaths

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Agent Selection Considerations

• Catastrophic public health consequences
• Mass casualties which overwhelm medical systems
• High morbidity or mortality
• Contagious

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What are the main bioterrorist weapons?
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Biological Agents of Highest Concern

• Bacillus anthracis (Anthrax)
• Yersinia pestis (Plague)
• Francisella tularensis (Tularemia)
• Botulinum toxin (Botulism)
• Variola major (Smallpox)
• Filoviruses and Arenaviruses (Viral hemorrhagic
  fevers)

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Most of the information on what would happen in a
Bioterrorist attack is based on what we know
about the natural disease.
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Why These Agents?

• Can cause disease via aerosol route
• Organisms fairly stable in aerosol
• Susceptible civilian populations
• High morbidity and mortality
• Some with person-to-person transmission
  (smallpox, plague, VHF)
• Difficult to diagnose and/or treat
• Previous development for Biological Warfare

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3 Categories of Bioterrorist Agents
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Category A

• Easily transmitted
• Easily disseminated
• High mortality rate
• Potential for major public health impact
• Can cause public panic and social disruption
• Requires special action for public health
  preparedness

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Bacterial Agents - Category A

• Bacillus anthracis
• Yersinia pestis
• Francisella tularensis

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Category B

• Moderate morbidity
• Low mortality
• Require specific non-standard diagnostic capacity
• Moderately easy to distribute
• Requires enhanced disease surveillance

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Bacterial Agents - Category B

• Brucellosis - Brucella species
• Q Fever - Coxiella burnetii
• Psittacosis - Chlamydia psittaci

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Bacterial Agents - Category B continued

• Glanders - Burkholderia mallei
• Meliodiosis - Burkholderia pseudomallei
• Typhus fever - Rickettsia prowazekii

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Bacterial Agents - Category B continued

• Water Threats
• Cholera -Vibrio cholerae
• Cryptosporosis - Cryptosporidium parvum (PROTOZOA)

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Bacterial Agents - Category B continued

• Food Safety Threats
• Escherichia coli O157H7
• Salmonella serotype Typhimurium
• Salmonella serotype Enteritidis
• Shigella sonnei
• Shigella flexneri, dysenteriae type 1
• Salmonella Typhi
• Vibrio cholerae

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Category C

• Newly discovered disease
• Easily obtained
• Easy to make and distribute
• Potential for high morbidity and mortality

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Types of Bioterrorist Events

• Announced
• (Overt)
• Unannounced
• (Covert)

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Likely Scenarios

• Overt threat
• anthrax letters
• device, e.g. aerosol bomb, Heating Air
  conditioning systems release
• Covert release
• food or water contamination, aerosol release,
  surface contamination, zoonotic attack

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Covert vs. Overt Event

• Overt Covert
• Recognition early delayed
• Response early delayed
• Treatment early delayed
• Responders Traditional Health Care
  FirstResponders Workers

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Delivery Systems

• Air
• aerosol most effective dissemination method
• droplet size lt 10 µm, 1-5 µm optimal
• Food
• Water
• Skin and mucous membranes

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Step 1 in Preparing forBioterrorism
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Recognition of Biological Attack

• Environmental detection not feasible
• Onset of symptoms is delayed
• incubation periods range from days to weeks
• Symptoms may be nonspecific
• initial presentation mimics flu
• Symptoms may be acute
• incapacitation, paralysis, coma, death

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Maintain a high level of suspicion in a number of
clinical situations

1. A rapidly increasing disease incidence in a
   normally healthy population
2. An epidemic curve that rises and falls during a
   short period of time
3. An unusual rise in the number of people seeking
   care, especially with fever, respiratory, or
   gastrointestinal complaints
4. An endemic disease rapidly emerging at an
   uncharacteristic time or in an unusual pattern

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1. Lower attack rates among people who have been
   indoors, compared with people who have been
   outdoors
2. Clusters of patients arriving from a single
   locale
3. Large numbers of rapidly fatal cases
4. Patient presenting with a disease that is
   relatively uncommon and has bioterrorism
   potential
5. Concurrent reports of increased animal deaths
6. Unusual age distribution
7. Atypical disease presentations

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Step 2 in Preparing forBioterrorism
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Develop and use epidemiological tools

1. Presence or lack of an appropriate exposure
   history
2. Travel to a location that has high-consequence
   disease transmission
3. Pathogens with unusual antimicrobial resistance
4. Routine surveillance and disease-reporting
   mechanisms

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American Academy of Family Physician Suggestions

• Know how to contact local and state health
  departments.
• Maintain contacts with local health officials.
• Maintain reference materials on the diagnosis and
  treatment of agents of bioterrorism.

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• Develop a bioterrorism response plan for your
  office. Be prepared to use infection control
  practices.
• Know the requirements for laboratory support.
• Be aware of proper post-exposure management for
  patients and health care staff.
• Develop skills in and resources for counseling
  patients to minimize the psychologic consequences.

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Clinical and microbiological characteristics
Agent Infective dose Incubation period Clinical presentation Case fatality
Bacillus anthracis 800050,000 spores (LD50) 114 days Cutaneous 160 days inhalational -Hemorrhagic pneumonia -Septicemia -Necrotic eschar -Dysentery Untreated inhalational and systemic, 100 Early treatment, 55 untreated cutaneous, 20 with treatment, lt1
Yersinia pestis lt100 organisms 17 days -Buboes -Pneumonia -Septicemisa untreated, 5090 treated, 515
F. tularemia 1050 organisms 114 days -Ulceroglandular -Ooculoglandular -Pneumonia -Septicemia untreated pneumonic and severe systemic disease, 3060 Untreated overall, 515 Treated , lt2
Brucella species 10100 organisms 560 days -Isolated fever -Orchitis -Endocarditis -Osteomyelitis Untreated, lt5
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Agent Person-person transmission Isolation procedure Biosafety level (BSL) Key microbiologic characteristics for presumptive identification
Bacillus anthracis NO Standard precautions BSL-2 with biosafety cabinet use Large GPR in chains nonhemolytic nonmotile Capsule in primary specimens catalase Sporulates aerobically
Yersinia pestis Yes (high) Droplet precautions - pneumonic disease until patient has received 3 days of treatment BSL-2 with biosafety cabinet use GNR that may have bipolar staining fried egg or hammered copper colonies at 4872 h nonlactose fermenter catalase oxidase-indole-urease negative nonmotile even at 28C
F. tularemia NO Standard precautions BSL-3 Tiny, pleomorphic poorly staining GNCB small gray-white nonhemolytic colonies after 210 days weakly catalase oxidase and urease negative b-lactamase Does not require X or V factor
Brucella species NO Contact isolation if draining lesions present BSL-3 Tiny, pale-staining GNCB small nonhemolytic colonies after 23 days Oxidase-catalase-urease
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Fear is the enemy.

• Know which of the biological warfare agents occur
  naturally in your area.
• If a biological attack is identified, keep a calm
  face.
• Remind people not to rush to the hospital or
  Doctors office.
• Help family members understand the facts.
• Do not let the news media and sensational
  reporting distract from accurate information.

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Since the 9/11 attacks, the federal government
has spent about 50 billion to improve the way
it detects and responds to biological threats.
But progress has been limited, and some security
experts say the threat is greater than it was.
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Scenario

• On April 1, 2009 a 20 year old male student from
  the University of North Carolina comes home to
  visit his family in Cayce.
• While he is home he develops a fever. This
  rapidly progressed to shortness of breath, chest
  pain, dry cough, headache, chills and rigors,
  generalized body aches (in the low back), head
  cold symtoms, and sore throat
• On April 5th his mother takes him to the E.R.
  With sever shortness of breath, chest pain and
  dry cough.
• Findings on clinical examination -
  undifferentiated febrile illness with incipient
  pneumonia, pleuritis, and hilar lymphadenopathy.

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• This was 3 days after the NCAA basketball
  tournament sweet 16 in Charlotte.
• What do you look for? Which organisms could it
  be and what additional information would you
  need? Who do you contact?
• Unusual respiratory disease in its early stages,
  could be difficult to distinguish from a natural
  outbreak of community-acquired infection,
  especially influenza or various atypical
  pneumonias.

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• Tularemia would be expected to have a slower
  progression of illness and a lower case-fatality
  rate than either inhalational plague or anthrax.
• Plague would most likely progress very rapidly to
  severe pneumonia, with copious watery or purulent
  sputum production, hemoptysis, respiratory
  insufficiency, sepsis, and shock.
• Inhalational anthrax would be differentiated by
  its characteristic radiological findings of
  prominent symmetric mediastinal widening and
  absence of bronchopneumonia.
• Anthrax patients would be expected to develop
  fulminating, toxic, and fatal illness despite
  antibiotic treatment.
• Milder forms of inhalational tularemia could be
  clinically indistinguishable from Q fever
  establishing a diagnosis of either would be
  problematic without reference laboratory testing.
  
• Presumptive laboratory diagnoses of plague or
  anthrax would be expected to be made relatively
  quickly, although microbiological confirmation
  could take days. Isolation and identification of
  F tularensis using routine laboratory procedures
  could take several weeks.