Download Handout-Bioterrorism

BIOTERRORISM
Dr. E. McNamara
Public Health Lab., SWAHB,
St. James’s Hospital
‘9/11 – Changes’
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Move to high risk
Biological Threat, specialist public arena
Newsworthy
Rare/eradicated infections
Low clinical experience
‘Autumn 2001 – USA’
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5 letters, finely milled anthrax spores
11 pulmonary anthrax (5 died)
7 cutaneous anthrax
All sent from Trenton, New Jersey, 1 person
American origin, B. anthracis
Criminal Act : Terrorist
‘Lessons Learned’
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No one prepared
Easy to produce contagious material
Easy to spread, (except aerosolization)
Small numbers affected, major concern
Copy cat phenomenon – ‘Hoaxes’
Lab. techniques for diagnosis
Major disruption
Use of prophylactic antibiotics
Benefits
• Co-operation internationally
– WHO
– CDC
– EU
• National preparedness Plans
• Multidisciplinary
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Government
Admininstrative
Emergency services
Medical
Scientific
History – Biological Warfare
• Water wells contaminated with corpses
• Siege Caffa, Crimea 1346, used plague
corpses
• British, gave Smallpox contaminated
blankets as presents to Native Americans
Modern History –
Biological Warfare
• Germany WWI
– sold anthrax infected horses
• WWI-II
– Many countries started biological programme
• WWII – Not Used
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UK
USA
Canada
Germany
Japan
5 million anthrax ‘cattle-cakes’
Botulinum
Plague
Salmonella
POW/Chinese trials
Post WWII
• USA
– 3400 people 1969, BTWC
– Allegation
• Korean War
• Cuba
– Misinformation, FBI to Soviets
• Soviets
– 1920 – 1969, BTWC signed
– 1975
Enlarged, Biopreparat
60,000 people
40-50 facilities
50 agents
Post WWII contd.
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1979 Sverdlovks, Anthrax, 69 died
1980 – 1990 Defections
1990 Yelsin – cessation?
Iraq 1974?, S. Africa 1980-1993
10 – 12 trying to acquire, evidence?
Preparing for Biological Attacks
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Enhance surveillance
Resource laboratories
Communication systems
Bioterrorism education
Stockpile vaccines and drugs
Molecular surveillance microbial strains
Support development diagnostic test
Support research Rx. and vaccines
CDC April 2000
Biological Agents
• Category A
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Easily dessiminated
High mortality
Public panic
Require special preparedness
• Category B
– Moderately easy to dessiminate
– Low mortality
– Need enhanced Dx./surveillance
• Category C
– Emerging pathogens
Anthrax, B. anthracis
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Zoonotic, spore forming rod
Soil reservoir, years
Affects large domestic and wild herbivoires
Worldwide
Humans
– Contact with infected animals/products
– Skin – cutaneous
– GIT/resp. – inhalation
• 2000 cases, cutaneous / year
• 5 cases USA, 1 case UK
• No cases Ireland for 25 years
Anthrax contd.
• Bioterrorist threat – inhalation spores
• No person – person spread ! (cutaneous?)
• Cutaneous
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Skin inoculation
Painless swelling
Papular – vescle – ulcer
Black eschar
Toxaemia
Mortality with Rx., < 1%.
• GIT
– Ingest contaminated meat
– Pain, diarrhoea, haematemesis, septicaemia
– Mortality > 50%
Anthrax contd.
• Dx. (Confirm reference laboratory)
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Hazard Group 3 – CL3
Non motile, GPB, Aerobic
Central / Terminal spores
Non–haemolytic
Sensitivity tests
• Rx. – Penicillin / Ciprofloxacin
• Post exposure prophylaxis = Ciprofloxacin
• Infection Contol – standard precautions
Inhalation Anthrax
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Bioterrorist agent
Mortality 90%
Incubation 1 – 60 days
Initial Phase (hrs – days)
– Non-specific symptoms
– Non-specific clincial signs + Dx. test
– Recover / Progress to fulminant
• Fulminant Phase
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Septicaemia / Toxaemia
Dyspnoea with CXR mediastenal widening
50% haemorrhagic menigitis and death
Mortality increased with short incubation
Small Pox
• Human, DNA variola virus
• 2 Forms
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Variola major, mortality 30% (3% vaccinated)
Variola minor, mortality 1%
Airborne spread, contact
Secondary attack rate 50% (unvaccinated)
Last death – 1978 UK.
WHO 1980, eradicated.
Small Pox contd.
• Incubation 12-14 days, rash further 2-4 days
• Fever, headache, myalgia, abdominal pain and
vomiting
• Delirium 15%
• Rash, centrifugal, face and extremities
• Copious virus on mucosal lesions
• Secondary bacterial pneumonia (mortality > 50%)
• Haemorrhagic Small Pox (95% mortality)
• Differental = Chicken Pox.
Small Pox contd.
• Dx.
– Hazard Group 4
– EM (Herpes : Pox) - CL3
– PCR (differentites Pox viruses) – CL4
– Culture – CL4
• Public Health Emergency – International
• Case: Standard, contact and airborne precautions
– Isolate: negative pressure, HEPA extract
– PPE. Decontamination protocol
– Immune HCW (vaccinated)
– Rx. = supportive
• Contact/Exposed
– Quarantine for 18 days - monitor temperature
• Infectious form onset of fever
Small Pox Vaccine
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Face – face contacts
HCW (core, prepardness)
Designated emergency personnel
Vaccine
– Live vaccinia virus (not variola)
– Vaccine site, infectious until scab heals
– Newer vaccine development
• S/E
• Efficancy
Small Pox Vaccine contd.
• CI – atopic dermatitis, pregnant,
immunocompromised
• S/E
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Fever headache, rigors, vastles
Generalised vaccinia (GV)
Eczema vaccinatum (EV)
Progressive vaccinia (PV)
Post vaccinial CNS (PVE)
• Incident 1968
– Life threatening = 52 / million
– Deaths = 1.5 / million
Cl. Botulinum
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Botulinum neurotoxin – most potent
Contaminated food, canned products
Wound botulism, contaminated soil, IVDA
Bioterrorism agent
– Aerosolisation – inhalation
– Contaminate food – ingestion
– Large numbers with acute flaccid paralysis
Cl. Botulinum contd.
• Incubation
– 2hrs – 8 days, Foodborne
– 1hr – 5 days, Aerosol
• Foodborne
– V+D, diplopia, dysarthria, weakness
– Ptosis, facial palsy, ↓gag Hypotonic
• Inhalation
– Dysplagia, nystagmins, ↓speech, ↓gait
• Terminal
– Progressive muscular paralysis
– Mortality 5% (with Rx.)
Cl. Botulinum contd.
• Differential Dx.
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Guillain-Barré
Myastheria gravis
Stoke
CNS despressants
Cl. Botulinum contd.
• Dx.:
– Detect botulinum toxin
– Culture
• Rx.:
– Antitoxin
– Supportive
• Infection Control – standard precautions
Plague
• Yersinia pestis – HG3
– GNCB, 02
• Aerosol, flea vector, person-person
• 3 Forms
– Bubonic – 90%
– Septicaemic – 10%
– Pneumonic – 1%
• Bioterrorist agent
– Aerosol – pneumonic
– Fleas – bubonic, septicaemic
Bubonic Plague
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Incubation 1-8 days
Fever, rigors, headache
Buboes – painful lymph nodes
15% develop pneumonic plague
Mortality = 12%
Septicaemic Plague
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Primary, or secondary to bubonic
Rigors, abdominal pain, V+D
Purpura, DIC, necrosis
Mortality = 30%
Pneumonic Plague
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Highest bioterrorism risk
Primary or secondary from haematogenous
Incubation 1-3 days
Pneumonic symptoms
Respiratory failure and shock
Mortality - ↓with rx. = 8%
Plague
• Dx.:
– Culture
• Rx.:
– Gentamicin, Streptomycin IV
– Ciprofloxacin, Doxycycline P.O.
• Infection Control:
– Standard and droplet, single room, surgical mask
• Contacts:
– Prophylaxis – Ciprofloxacin – 72 hrs.
Tularaemia
• F. tularensis
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Non-motile, aerobic, GNCB, zoonosis, rabbits, deerfly
HG3
Worldwide
Low inoculum – 10 CFU
• Ulceroglandular
• Typhoidal
– Mortality 35-60% (untreated)
– Inhalation
• Infection Control – standard (no person-person)
• Rx. Gentamicin/Streptomycin – 10 days
• Contacts : prophylaxis