Biological Agents and Terrorism

Terrorism and Biologic Agents

Biological Agents and Terrorism


Objectives

• Learn how to perform an assessment of a biologic agent such as anthrax in a terrorism situation.

• Discuss the history of anthrax as a biologic weapon

• Recognize various disease presentations of anthrax.


Objectives

• Discuss the pathogenesis of anthrax

• Recognize naturally occurring anthrax presentations versus weaponized anthrax

• Learn how to medically manage anthrax infections.


Biologic Agent Case• Winter in the Midwest

• Typical Year– Many complaints of a runny

nose

– Many complaints of a cough

– Many complaints of a tactile fever


Biologic Agent Case

• A 40 y/o police officer presents with a fever and muscle aches. He is pale, has a temperature of 102°F. His physical exam and labs are unremarkable so he is discharged and given flu instructions. He says his partner is also ill.


Biologic Agent Case• Later, a 35 y/o female clerk also presents

complaining of myalgias, shaking chills, and vomiting. She is pale, and has a temperature of 102.4°F. Her physical exam is non-focal, she improves with antipyretics and the patient is sent home with viral syndrome instructions.


Biologic Agent CaseThe next day several more patients present with fever, chills and myalgias.


Biologic Agent Case• The 40 yo policeman

returns 3 days later because he is feeling much worse and is short of breath.

• This is the chest x-ray that was obtained


Biologic Agent Case• A mother brings in her

adolescent son for a strange black scab/rash that started out as a small papule but formed a black painless eschar over the past 5 days.


Biologic Agent Case• Another family brings in

their adolescent daughter for evaluation of a “bad infection”

• Surrounding facial edema is uncomfortable/painful

• The developing eschar is relatively painless


Biologic Agent Case• The ED calls your office

informing you of the admission of the 35 yo female for fever, mental status changes, meningismus, pneumonia, hypoxia, respiratory distress and shock.

• After LP, the gram-stain was described as gram positive rods with spores.


What is the Agent?


Anthrax (Bacillus anthracis)

• Where is it found naturally?

• History as a biological weapon

• How does it cause disease?

• What types of disease does it cause (clinical effects)?

• Treatment


Naturally Occurring Anthrax

• Caused by a gram-positive spore forming rod

• Spore if very hardy can survive for decades in the soil

• Important veterinary disease as herbivores may be prone to the disease if they feed in ‘anthrax zones’


Naturally Occurring Anthrax• Endemic cases are usually present as

cutaneous disease (95%; <1-20% mortality)

• Contracted by contact of abraded skin with products of infected cattle, sheep and goats

• Products include hides, hair, wool, bone and meat.


Naturally Occurring Anthrax

• Inhalational anthrax (wool sorter’s disease) from inhalation of spores from textile and slaughterhouse workers (<5% cases; 45-89% mortality)

• Gastrointestinal Anthrax is very rare and occurs from consuming infected meat (<5%; >50% mortality)


Weaponized Anthrax• WHO estimates that 50 Kg dispersed

along a 2 Km line upwind of a city of 500,000 could cause 125,000 infections and 95,000 deaths

However

• May be difficult to weaponize into small enough particles

• ID50 of 8,000 to 10,000 spores


Weaponized Anthrax History

Sverdlovsk, Russia, 1979• Accidental release from biological

weapons facility due to a faulty filter• Plume swept over city by the wind• ≥77 cases, 66 deaths• Last person became ill 43 days after

initial release


Weaponized Anthrax History

• October 2001 letter associated Anthrax outbreak

• 22 cases– 11 Inhalational (5 deaths)– 11 Cutaneous (No deaths)

• Very different distribution compared to naturally occurring disease


Anthrax Disease Process• Anthrax has at least three proteins

which play a role in virulence• A-B model of toxicity• Edema factor (EF), Lethal factor (LF)

and Protective antigen (PA)• EF and LF need PA to get into the cell

to cause damage


Anthrax Disease Process

• EF + PA creates edema toxin

• LF + PA creates lethal toxin

• The toxins cause lymphatic necrosis which leads to the release of Bacillus anthracis

Anthrax Disease Process


Cutaneous Anthrax• Progression of painless lesions

Papule/macule – pruritic

Vesicle/bulla – clear or serosanguinous

Ulcer – nonpitting, gelatinous edema

Eschar – black, depressed, rarely scars,

24-48 hrs

days


Cutaneous Anthrax


Inhalational Anthrax Clinical Features

• Initially starts with a non-specific flu-like illness and then progresses to:– Respiratory Distress– Shock

• May see a widened mediastinum on x-ray

Anthrax – Hemorrhagic Meningitis


Gastrointestinal Anthrax

• Nausea, anorexia, vomiting, fever• Progresses to severe abdominal pain

and bloody emesis and diarrhea• Ascites may develop on day 2 - 4• Death 2 to 5 days after onset of

symptoms• Very difficult to diagnose


Treatment

Cutaneous Anthrax

• without systemic signs, extensive edema or lesions located on head and neck.

• Initial recommended treatment:– Doxycycline or Ciprofloxacin PO for 60 days


TreatmentCutaneous Anthrax • with systemic signs,

extensive edema or lesions on the head and neck.

• Initial recommended treatment:– Doxycycline or Ciprofloxacin IV– May switch to PO when clinically appropriate


Treatment

Inhalational, GI, Sepsis

• Initial recommended treatment:– Doxycycline or Ciprofloxacin IV– May switch to PO when clinically

appropriate


Questions?


Question #1The antibiotic of choice among the following for

treating an anthrax infection is:

a. Cefuroxime

b. Doxycylcine

c. Penicillin

d. Pentamidine

e. Trimethoprim-sulfamethoxazole


Question #2The most common naturally occurring form of

anthrax is:

a. Cutaneous

b. Gastrointestinal

c. Inhalational

d. Ocular

e. Mediastinal


Question #3

Which of the following is an isolated protein necessary for the virulence of anthrax?

a. Edema toxin

b. Lethal toxin

c. Lymphatic factor

d. Necrosis factor

e. Protective antigen


Question #4

The order of development of the classic cutaneous anthrax lesion is:

a. Bullae, vesicle, ulcer, eschar

b. Papule, vesicle, ulcer, eschar

c. Vesicle, bullae, eschar, ulcer

d. Ulcer, vesicle, bullae, eschar


Question #5After low-level germination at the site of entry to

the body, anthrax may be taken up by:

a. Basophils

b. Eosinophils

c. Lymphocytes

d. Macrophages

e. Neutrophils


This completes the current presentation.

Biological Agents and Terrorism

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