Title: Biological Weapons of Mass Destruction
1Biological Weapons of Mass Destruction
- Stephen Waring, DVM, PhD
- Associate Director of Research
- Center for Biosecurity and Public Health
Preparedness
- Assistant Professor of Epidemiology and
Biological Sciences
2Its an isolated case. There is no terrorism.
Tommy Thompson, Sec of HHS After death of Bob Ste
vens (1st of 4)
3The gravest danger our Nation faces lies at the
crossroads of radicalism and technology.
History will judge harshly those who saw this co
ming danger but failed to act. In the new world
we have entered, the only path to peace and
security is the path of action.
President Bush The National Security Strategy o
f the United States of America September 17, 2002
4What is bioterrorism?
- Intentional or threatened use of viruses,
bacteria, fungi, or toxins from living organisms
to produce death or disease in humans, animals,
or plants
5How real is the threat?
Threats reported to FBI, 1996-1999
We expect the trend to continue or even increas
e as we get into
the new century.
Through first 4 months
Source FBI
6Intentional food contamination salmonellosis
- The Dalles, Oregon in Fall of 1984
- 751 cases of Salmonella
- Eating at salad bars in 10 restaurants
- Criminal investigation identified perpetrators as
followers of Bhagwan Shree Rajneesh
Source Torok et al. JAMA 1997278389
7Multistate Outbreak Anthrax, 2001
4 deaths
NY letters
DC letter
Number of cases (all)
October
September
Postmarked data of known contaminated letter
MMWR 200150(43)941-948
8Considerations
- Catastrophic public health consequences
- Mass casualties overwhelm medical systems
- High morbidity or mortality
- Contagious
- Require comprehensive PH preparedness
- stockpile therapeutics
- enhanced surveillance or diagnostics
- response planning
- Heightened public perception
9Biological Agents of Greatest Concern
- Bacillus anthracis (Anthrax)
- Variola major (Smallpox)
- Yersinia pestis (Plague)
- Francisella tularensis (Tularemia)
- Filo-/Arenavirus (Viral hemorrhagic fevers)
- Botulinum toxin (Botulism)
10Why These Agents?
- Infectious via aerosol
- Organisms fairly stable in environment
- Susceptible civilian populations
- High morbidity and mortality
- Person-to-person transmission (smallpox, plague,
VHF)
- Difficult to diagnose and/or treat
- Previous development for BW
11Advantages of using biologicalagents as weapons
- Easy to obtain
- Inexpensive to produce
- Potential for dissemination over large geographic
area
- Creates panic
- Can overwhelm medical services
- Perpetrators escape easily
12Epidemiologic Clues for Covert Bioterrorism
Attacks
- Large numbers of persons with the same illness
- Uncommon disease agents
- Geographical, seasonal
- Increased deaths in animal population
- Higher incidence than expected from a disease
13Public Health Response to Bioterrorism
- CDC recommends 4 areas of preparedness
- Reinforce PH surveillance systems
- Increase epidemiologic capacity
- Enhance PH laboratory capability
- Develop and enhance communication networks
14Covert vs. Overt Event
15 Anthrax
- Human zoonotic disease
- Woolsorters disease
- Caused by Bacillus anthracis
- Soil reservoir
- Normally humans infected by contact with infected
animals or byproducts
16Anthrax as a bioweapon
- Features of anthrax suitable as BT agent
- Fairly easy to obtain, produce and store
- Spores easily dispersed as aerosol
- Moderately infectious
- High mortality for inhalational (86-100)
17Anthrax as a bioweapon
- Aerosol method of delivery
- cause primarily inhalational disease
- Spores on particles of 1-5 µm size
- Optimal size for deposition into alveoli
- Form of disease with highest mortality
- Would infect the largest number of people
18Anthrax as a bioweapon
- Sverdlovsk, Russia 1979
- Accidental release from anthrax drying plant
- 79 human cases
- All downwind of plant
- 68 deaths
- Some infected with multiples strains
19Sverdlovsk, Russia Anthrax Incident, 1979
Biopreparat
20Dispersion of spores
21Anthrax Cutaneous
- Most common form (95)
- Inoculation of spores under skin
- Incubation hours to 7 days
- Small papule -- ulcer surrounded by vesicles
- Painless eschar with edema
- Death
- 20 untreated rare if treated
Source www.bt.cdc.gov
22Anthrax Inhalational
- Incubation 1 to 43 days
- Initial symptoms (2-5 d)
- flu-like
- Terminal symptoms (1-2d )
- High fever, dyspnea, cyanosis
- hemorrhagic mediastinitis/effusion
- Rapid progression shock/death
- Mortality 100 despite aggressive Rx
From JAMA 19992811735-1745
23Anthrax Treatment
- Antibiotics
- Penicillin (if PCN susceptible), Doxycycline, or
Ciprofloxacin
- Supportive care
- Standard precautions, no need for quarantine
- Duration of treatment dependent on form of
anthrax and/or vaccine use
- Early treatment improves prognosis
24Anthrax Post-Exposure Treatment
- Start oral antibiotics
- Ciprofloxacin
- Doxycycline
- Amoxicillin (if known PCN sensitive)
- Antibiotics
- 60 days without vaccine
- 30 days with 3 doses of vaccine
25Anthrax Vaccine
- Current U.S. vaccine (FDA Licensed)
- Attenuated non-encapsulated strain
- Protective against cutaneous (human data) and
possibly inhalational anthrax (animal data)
- Injections at 0, 2, and 4 weeks, then 6, 12, and
18 months, yearly boosters
- 3 dose schedule may be effective
- 83 serologic response after 3 doses 100 after
5 doses
- limited availability
26Decontamination
- No person to person transmission
- Highest risk of infection at initial release
- Duration of aerosol viability
- Several hours to one day under optimal
conditions
- Covert aerosol long dispersed by recognition 1st
case
- Risk of secondary aerosolization is low
- Heavily contaminated small areas
- May benefit from decontamination
- Decontamination may not be feasible for large
areas
27Decontamination
- Skin, clothing
- Thorough washing with soap and water
- Avoid bleach on skin
- Instruments for invasive procedures
- Sterilize, e.g. 5 hypochlorite solution
- Sporicidal agents
- Sodium or calcium hypochlorite (bleach)
28Decontamination
- Suspicious letters/packages
- Do not open or shake
- Place in plastic bag or leakproof container
- If visibly contaminated or container unavailable
- Gently cover paper, clothing, box, trash can
- Leave room/area, isolate room from others
- Thoroughly wash hands with soap and water
- Report to local security / law enforcement
- List all persons in vicinity
29Decontamination
- Opened envelope with suspicious substance
- Gently cover, avoid all contact
- Leave room and isolate from others
- Thoroughly wash hands with soap and water
- Notify local security / law enforcement
- Carefully remove outer clothing, put in plastic
- Shower with soap and water
- List all persons in area
30Smallpox Overview
- Important cause of morbidity and mortality in
developing world until 1970s
- up to 30 mortality in unvaccinated
- 1980 - Global eradication
- Person-to-person transmission (aerosol/contact)
- Humans only known reservoir
Variola major
31Smallpox Clinical Features
- Prodrome (incubation 7-17 days)
- Acute onset of fever, malaise, headache,
backache, vomiting, occasional delirium
- Transient erythematous rash
- Exanthem
- Begins face, hands, forearms
- Spread to lower extremities then trunk over 7
days
- Synchronous progression
- macules--vesicles--pustules--scabs
- Lesions on palms /soles
- Mortality up to 30 for unvaccinated
32Smallpox vs. Chickenpox
33Smallpox Vaccination Complications
- Most common
- Inadvertent inoculation (skin, eye)
- Less Common
- Generalized vaccinia
- Post-vaccination encephalitis (2.8/million)
- Fetal vaccinia
- Eczema vaccinatum (4.5/million)
- Vaccinia necrosum (0.7/million)
- Primary vaccination - 1 death/million
- Revaccination - 0.2 deaths/million
34Smallpox Vaccination Complications
Eczema vaccinatum
Self-inoculation
Vaccinia necrosum
Courtesy WHO
35Smallpox Medical Management
- Strict respiratory/contact isolation of patient
- Patient infectious until all scabs have
separated
- Notify public health authorities immediately for
suspected case
- Identification of contacts within 17 days of the
onset of cases symptoms
36Plague Overview
- Rodent flea natural vector
- Mammalian hosts
- rodents, squirrels, chipmunks, rabbits, and
carnivores
- Enzootic or Epizootic in US
- About 10-15 cases/year
- Mainly SW states
- Bubonic most common form
37Plague Clinical Forms
- Bubonic
- Inguinal, axillary, or cervical LN most common
- 80 bacteremic
- 60 mortality untreated
- Primary or secondary septicemic
- 100 mortality untreated
- Pneumonic
- From aerosol or septicemic spread to lungs
- Person-to-person transmission by respiratory
droplet
- 100 mortality untreated
38Plague Bubonic
- Incubation 2-6 days
- Sudden onset HA, malaise, myalgia, fever, tender
LNs
- Regional lymphadenitis (Buboes)
- Cutaneous findings
- possible papule, vesicle, or pustule at
inoculation site
- Purpuric lesions - late
Source USAMRICD
39Plague Septicemic
- Primary or secondary(from bubonic or pneumonic)
- Severe endotoxemia
- Systemic inflammatory response syndrome
- Shock, DIC, ARDS
40Plague Pneumonic
- Incubation 1-3 days
- Sudden onset HA, malaise, fever, myalgia, cough
- Pneumonia progresses rapidly (24-48h) to dyspnea,
stridor, cyanosis, hemoptysis
- Death from respiratory collapse, sepsis
Source USAMRICD
41Plague Differential Diagnosis
- Pneumonic
- Bioterrorism threats
- Anthrax
- Tularemia
- Melioidosis
- Other pneumonias
- CAP
- Influenza
- HPS
- SARS
- Bubonic
- Staph/streptococcal adenitis
- Glandular tularemia
- Cat scratch disease
- Septicemic
- gram-negative sepsis
- Meningococcemia
- RMSF
- TTP
42Plague Medical Management
- Antibiotic therapy
- Gentamicin or Streptomycin
- Tetracyclines
- Sulfonamides
- Chloramphenicol (meningitis/pleuritis)
- Supportive therapy
- Isolation and droplet precautions for pneumonic
plague until sputum cultures negative
43Plague TOPOFF
Aerosol of Y pestis released at Denver Performing
Arts Center
44Tularemia Overview
- Disease of Northern Hemisphere
- Most cases associated with rabbits and hares or
ticks
- About 200 cases/year in U.S.
- most in South central and West
- majority of cases in summer
- Low infectious dose
- 1 to 10 organisms (aerosol or ID)
- No person-to-person transmission
45Tularemia Clinical Forms
Lymphoglandular
Ulceroglandular
Oculoglandular
46Tularemia Pneumonic
- Incubation 3 to 5 days (range 1-21 days)
- Abrupt onset fever, chills, headaches, myalgia,
non-productive cough
- Segmental/lobar infiltrates, hilar adenopathy,
effusions
- Mortality 30 untreated less than 10 treated
47Pneumonic Tularemia Differential Diagnoses
- Community acquired pneumonia (CAP)
- Atypical CAP (Legionella, Mycoplasma)
- Streptococcal pneumonia, Influenza, H. influenza
- Other Zoonoses
- Brucellosis
- Q Fever
- Pneumonic plague
- Histoplasmosis
- Inhalational Anthrax
- HPS
48Viral Hemorrhagic Fevers (VHF) Overview
- Caused by several different viruses families
- Filoviruses (Ebola, Marburg)
- Arenaviruses (Lassa, Junin, Machupo, Sabia,
Guanarito)
- Bunyaviruses
- Flaviviruses
- Natural vectors - virus dependent
- rodents, mosquitoes, ticks
- No natural occurrence in U.S.
49VHF Clinical Presentation
- Usual patient history
- Foreign travel to endemic or epidemic area
- Rural environments
- Nosocomial exposure
- Contact with arthropod or rodent reservoir
- Domestic animal blood exposure
- Incubation
- Typical 5 to 10 days
- Range 2 to 16 days
50VHF Clinical Presentation
- Symptoms
- Fever, headache, malaise, dizziness
- Myalgias
- Nausea/vomiting
- Initial signs
- Flushing, conjunctival injection
- Periorbital edema
- Positive tourniquet test
- Hypotension
51VHF Clinical Presentation
- Other signs/symptoms
- Prostration
- Pharyngeal, chest, or abdominal pain
- Mucous membrane bleeding, ecchymosis
- Shock
- Usually improving or moribund within a week
(exceptions HFRS, arenaviruses)
- Bleeding, CNS involvement, marked SGOT elevation
indicate poor prognosis
- Mortality agent dependent (10 to 90)
52VHF Differential Diagnosis
- Bacterial
- Typhoid fever, meningococcemia, rickettsioses,
leptospirosis
- Protozoa
- Falciparum malaria
- Other
- Vasculitis, TTP, Hemolytic Uremic Syndrome (HUS),
heat stroke
53Botulism Overview
- Caused by toxin from Clostridium botulinum
- toxin types A, B, E, most commonly associated
with human disease
- most potent lethal substance known to man (lethal
dose 1ng/kg)
- C. botulinum spores found in soil worldwide
- 100 reported cases/year in the U.S.
- infant most common (72)
- food borne not common
- No person-to-person transmission
54Botulism Clinical Forms
- Foodborne
- toxin produced anaerobically in improperly
processed or canned, low-acid foods contaminated
by spores
- Wound
- toxin produced by organisms contaminating wound
- Infant
- toxin produced by organisms in intestinal tract
- Inhalation botulism
- not naturally occurring, developed as BW weapon
55BotulismClinical Presentation
- Incubation 18 to 36 hours (dose dependent)
- Afebrile, alert, oriented normal sensory exam
- early nausea, vomiting, diarrhea
- Cranial Nerve symptoms
- ptosis, blurry/double vision, difficulty
swallowing/talking, decreased salivation
- Motor symptoms (progressive)
- bilateral descending flaccid paralysis --
respiratory paralysis
- Death 60 untreated
56BotulismDifferential Diagnoses
- Neuromuscular disorders
- Stroke syndrome
- Myasthenia gravis
- Guillain-Barre syndrome (Miller-Fisher variant)
- Tick paralysis
- Atropine poisoning
- Paralytic shellfish/puffer fish poisoning
- Diagnosis based on clinical presentation and
laboratory confirmation
57Clinical Summary
58Summary
59How will we know?
- unusual temporal/geographic clustering
- patients presenting with signs and symptoms that
suggest an outbreak
- unusual age distribution for common diseases
(chickenpox in adults)
- large number of cases of acute flaccid paralysis
with prominent bulbar palsies, suggestive of a
release of botulinum toxin
60What will we do?
- Make a plan
- Know the plan
- Practice the plan
- http//www.readygov.com
- http//www.bt.cdc.gov
- http//www.tdh.state.tx.us
- http//www.ci.houston.tx.us
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