Chapter 110

Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc.

Chapter 110

Potential Weapons of Biologic, Radiologic, and Chemical

Terrorism

Copyright © 2013, 2010 by Saunders, an imprint of Elsevier Inc. 2

Potential Weapons of Terrorism Bacteria Viruses Biotoxins Chemical weapons

Nerve agents and mustard gas Radiologic weapons


Bacteria and Viruses Anthrax

Bacillus anthracis • Aerobic gram-positive bacterium

Dormant form viable for decades Inhalational, cutaneous, gastrointestinal Enters the body via the skin or mucous

membranes of the respiratory tract Not transmitted person to person


Inhalational Anthrax Anthrax spores deposit in alveolar space Even with treatment, mortality can be high Clinical latency 2 days to 4 weeks

Mature bacilli release toxins• Hemorrhage, edema, and necrosis• If toxins reach critical level, antibiotics cannot prevent death

Initial symptoms Fever, cough, malaise, weakness

Second stage (2–3 days later) Sudden increase in fever, severe respiratory distress,

septicemia, hemorrhagic meningitis, and shock


Cutaneous Anthrax Symptoms 1–7 days after exposure to spores

Broken skin most vulnerable Injury can develop anywhere spores land Initial lesion: small papule or vesicle associated with local

itching• 2 days: lesion enlarges into painless ulcer with necrotic core• 7–10 days after symptoms: black eschar forms, then dries,

loosens, and sloughs off by days 12–14 In most cases, lesions resolve without complications

or scarring Treatment is usually successful, but 20% die without

antibiotic treatment


Treatment of Anthrax Infection Respiratory

IV ciprofloxacin IV doxycycline Raxibacumab (not yet tested in humans)

Cutaneous Oral ciprofloxacin Oral doxycycline


Pre-Exposure Vaccination BioThrax (formerly known as Anthrax Vaccine

Adsorbed, or AVA) Licensed for use in United States Inactivated cell-free preparation 3 subQ injections 2 weeks apart, then at 6, 12,

and 18 months Annual boosters recommended Persons at high risk should be vaccinated

• Military personnel and those who handle animal products from anthrax-endemic areas, including veterinarians, laboratory workers, and others


Postexposure Prophylaxis Oral antibiotics + Anthrax vaccine Vaccine at 0, 2, and 4 weeks BioThrax not currently licensed for

postexposure use Emergency use: investigational new drug

application


Francisella tularensis (Tularemia) “Rabbit Fever” and “Deer Fly Fever”

Potentially fatal Skin, mucous membranes, GI tract, or lungs Acute influenza-like symptoms initially Pneumonia and pleuritis can develop Treatment

IM streptomycin or IM gentamicin Mass outbreak and prophylaxis: oral doxycycline

or ciprofloxacin


Yersinia pestis Gram-negative bacillus Plague Two principal forms

Bubonic: tender, enlarged, and inflamed lymph nodes• Rarely develops into pneumonic• Not transmitted person to person

Pneumonic: inflammation of the lungs• Transmitted by cough


Pneumonic Plague Transmitted person to person Acquired by inhaling aerosolized Yersinia

pestis With no treatment, rapidly progresses to

respiratory failure and death Treatment is streptomycin (IM) and

gentamicin (IM or IV) Mass casualty—oral doxycycline or

ciprofloxacin


Smallpox No proven treatment Highly contagious; fatality rate 30% ACAM2000 approved vaccine Imvamune (in clinical trials) Vaccine produces high level of immunity for

5–10 years (before exposure or within a few days of exposure)

Pathogenesis and clinical manifestations Transmission


Smallpox Vaccine Efficacy Duration of protection Administration Interpreting the response


Smallpox Vaccine Adverse effects

Mild effects• Local inflammation, along with swelling and tenderness in

regional lymph nodes• Transient symptoms (fever, headache, muscle aches, fatigue)

Moderate to severe• Eczema vaccinatum, generalized vaccinia, progressive

vaccinia, postvaccinial encephalitis, fetal vaccinia, possible cardiac effects

• Vaccinia immune globulin (VIG) and cidofovir (Vistide) Who should not be vaccinated?

Persons with eczema, atopic dermatitis, immunodeficiency, pregnancy

Persons living with someone who has contraindications


Biotoxins Botulinum toxin

Clostridium botulinum Blocks release of acetylcholine from cholinergic

neurons With no treatment, rapidly leads to paralysis and

respiratory failure and death Classic symptoms: double vision, blurred vision,

drooping eyelids, slurred speech, dry mouth, dysphagia, muscle weakness, descending flaccid paralysis


Botulinum Toxin Treatment

Prolonged supportive care• Fluid/nutritional support• Mechanical ventilation

Immediate infusion of botulinum antitoxin


Ricin Toxin present in castor beans

Extraction from the “mash” when beans are processed to make castor oil

Powder, pellet, mist, or dissolved in water or a weak acid

Inhibits protein synthesis Treatment is purely supportive

No antidote for ricin Vaccine in development


Ricin: Clinical Manifestations Inhalation

In a few hours: coughing, chest tightness, difficulty breathing, nausea, muscle aches

Later: severely inflamed/edematous airway; cyanosis and death can follow

Ingestion Intestinal and gastric hemorrhage, vomiting, diarrhea; then

liver, spleen, kidneys may fail; death within 10–12 days of ingestion

Injection Severe symptoms and death; impractical route for terrorism


Chemical Weapons Nerve agents

Produce a state of cholinergic crisis, characterized by excessive muscarinic stimulation and depolarizing neuromuscular blockade

Treatment: mechanical ventilation, atropine, pralisoxime, and diazepam


Chemical Weapons Sulfur mustard (mustard gas)

Alkylating agent and vesicant Can be vaporized into air or released into water

supply Injuries severe, but fatality rate is low During World War I: killed less than 5% of victims Symptoms of toxicity depend on the dose, the

tissue involved, and the duration of exposure Treatment: rapid decontamination, supportive

care, and drug therapy


Radiologic Weapons Nuclear bombs

Immediate and delayed impact Nuclear power plant attack

Radiation exposure in area Dirty bombs (radiologic dispersion devices)

Radioactive material formulated into powder or pellets


Drugs for Radiation Emergencies Potassium iodide

Prompt treatment necessary Penetrate zinc trisodium and penetrate

calcium trisodium Treatment within 24 hours most effective

Prussian blue (Radiogardase)

Chapter 110

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imprint of elsevier

days latersudden

necrotic core710 days

local itching2 days

person copyright

mucous membranes

potential weapons of

anthraxendemic areas