31.1

Biological Warfare Agents

Chapter 31

Biological Warfare Agents

Introduction

Biological warfare (BW) agents infect the body via the same portals

of entry as infectious organisms that occur naturally. These include

inhalation into the respiratory tract, ingestion into the GI tract, and

absorption through mucous membranes, eyes, skin, or wounds. Most

BW agents will enter the body through inhalation. Usually, the

disease produced by a BW agent will mimic the naturally occurring

disease, but the clinical presentation can be different if delivery of

an agent occurs through a portal that differs from the natural portal.

Detection

 Compressed epidemiology with record numbers of sick and

dying in a short time.

 High attack rates (60%–90%).

 High incidence of pulmonary involvement when usual form

of infection is not (eg, anthrax).

 Incidence of a particular disease in an unlikely location.

 Increased deaths of animals of all species.

 Near simultaneous outbreaks of several different epidemics

at the same site.

 Biological Identification Detection System or standoff BW

detectors alarming.

 Direct evidence of an attack such as contaminated or

unexploded munitions.

Diagnosis

The first indication of an attack may be when large

numbers of patients present with the same constellation

of signs and symptoms, especially for a disease that is

not endemic to the area of operations.
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Emergency War Surgery

Rapid diagnostic tests may be available in forward areas to

assist clinicians in early diagnosis:

 Isolation of the etiologic agent can occur within 1–2 days for

some agents.

 Enzyme-linked immunosorbent assays (ELISA).

 Genome detection by polymerase chain reaction (PCR).

 Antibody detection.

Prevention and Protection

 Immunizations: Anthrax, and in specific scenarios, smallpox

and plague.

ο Pre- or postexposure chemoprophylaxis—anthrax, plague,

Q fever, and tularemia. Chemoprophylaxis for anthrax is

presently FDA-approved for postexposure only.

♦ Investigational new drugs exist for the treatment of

Argentine hemorrhagic fever, botulinum toxin, Q fever,

Rift Valley fever, Venezuelan Equine Encephalitis (VEE),

and tularemia.

 Protective clothing and mask.

Decontamination —Personnel, Equipment, and Clothing

 Mechanical decontamination removes, but not necessarily

neutralizes, the BW agent.

ο Brushing to ensure loosening of the BW agent from the

surface.

ο Filtration and chlorination of drinking water to remove

organisms.

 Chemical decontamination renders BW agents harmless

through the use of disinfectants.

ο Soap and water followed with copious rinsing with water

is often sufficient.

ο For patients requiring urgent decontamination, biologic

agents are neutralized within 5 minutes when contaminated areas are washed with a 0.5 % hypochlorite solution

(1 part household bleach mixed with 9 parts water).

ο Do not use hypochlorite in the eyes, abdominal cavity,

or on nerve tissue.

ο A 5% hypochlorite solution (ie, household bleach) may be

used to decontaminate clothing or equipment.
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Biological Warfare Agents

 Physical decontamination such as heat and solar ultraviolet

(UV) radiation.

ο Dry heat for 2 hours at 160°C.

ο Autoclaving at 120°C under 1 atm of overpressure for 20

minutes.

ο UV radiation difficult to standardize.

 Dry biological agents can be a hazard through secondary

aerosolization; but adequate liquid decontamination will

prevent this hazard. There is no vapor hazard, and special

protective masks are generally not required for surgical

personnel.

Infection Control

Infection control procedures should be reinforced for situations

involving BW agents. Standard precautions are appropriate for

BW agents once they have been identified. For an undifferentiated febrile illness following a BW agent attack:

 Place patients together in an isolated setting such as a

designated tent or other structure.

 Surgical masks may be placed on patients when isolation is

not possible.

 Employ respiratory droplet precautions along with standard

precautions until diseases transmissible by droplet (such as

plague and smallpox) have been excluded.

Medical Evacuation

 If plague, smallpox, and the hemorrhagic fevers can be

excluded, patients may be evacuated using standard

precautions and the disease-specific precautions.

Plague and smallpox are internationally quarantinable

diseases (IQDs). Do not evacuate patient across

international borders unless authorized by the theater

surgeon.

 Isolation precautions should be added to standard precautions.

 Immediately upon diagnosing patients with smallpox, the

line and medical chain of command must be notified.

 Observe strict quarantine.
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Emergency War Surgery

ο Standard and respiratory droplet isolation precautions.

♦ Standard precautions.

◊ Hand washing after patient contact.

◊ Use of gloves when touching blood, body fluids,

secretions, excretions, and contaminated items.

◊ Use of mask, eye protection, and gown during

procedures likely to generate sprays of blood, body

fluids, secretions, or excretions.

◊ Handle contaminated patient-care equipment and

linen in a manner that precludes transfer of microorganisms to individuals or equipment.

◊ Practice care when handling sharps and use pocket

mask or other ventilation device when ventilating

the patient.

◊ Place patient in private room when possible. Limit

the movement or transfer of patient.

♦ Droplet precautions.

◊ Standard precautions plus:

Place patient in private room or with someone

with the same infection. If not feasible, maintain

at least 1 m distance between patients.

Use of a mask when working within 1 m of patient.

Mask the patient if he/she needs to be moved.

ο All contacts should be vaccinated within 7 days of

exposure and quarantined together for at least 17 days

following the most recent exposure.

Hemorrhagic fevers—Hanta, Ebola, Lassa, Rift Valley, HFRS

 Except for yellow fever, quarantine is not mandatory;

however, person-to-person transmission is possible, therefore,

universal precautions are recommended.

 Medical evacuation may result in increased morbidity and

mortality, thus treatment at local MTFs is preferred.

 When necessary, patients may be evacuated using universal

and respiratory droplet isolation precautions.
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Biological Warfare Agents

Biological Agents

There are two biological toxins that are potential BW agents:

botulinum and ricin (see Table 31-1).

Table 31-1

Biological Toxin Signs/Symptoms Medical Management

Botulinum Cranial nerve palsies Antitoxin/supportive care

Paralysis

Respiratory failure

Ricin Fever, cough, SOB

Arthralgias, pulmonary Nonspecific/Supportive care

edema

Bacterial Agents

The bacteria or rickettsia most often considered to be potential

BW threat agents include Bacillus anthracis (anthrax), Brucella

sp. (brucellosis), Vibrio cholerae (cholera) Burkholderia mallei

(glanders), Yersinia pestis (plague), Francisella tularensis

(tularemia), and Coxiella burnetii (Q Fever) (see Table 31-2).

Table 31-2

Bacterial Signs/Symptoms Medical Management

Anthrax Fever, malaise, cough, SOB, Ciprofloxacin

cyanosis

Plague High fever, chills, headache, Streptomycin

cough, SOB, cyanosis

Brucellosis Fever, headache, myalgias, Doxycycline

sweats, chills

Cholera Massive watery diarrhea Fluid therapy and antibiotics

(tetracycline, doxycycline or

ciprofloxacin)

Tularemia Local ulcer, lymphadenopathy, Streptomycin

fever, chills, headache, and

malaise

Q-fever Fever, cough, and pleuritic chest Tetracycline

pain
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Emergency War Surgery

Viral Agents

A number of viruses are BW agents, including smallpox, the

viral hemorrhagic fevers (VHF), and the alpha virus that causes

VEE (see Table 31-3).

Table 31-3

Viral Signs/Symptoms Medical Management

VEE Fever and encephalitis Nonspecific/supportive care

Smallpox Malaise, fever, rigors, vomiting, Antiviral under investigation

headache followed by pustular

vesicles

VHF Flushing of the face, petechiae, Nonspecific/supportive care

bleeding, fever, myalgias,

vomiting, and diarrhea