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Author:    Pamela Dugle (RN, MSN)

Purpose/Goals

The goal of the Biological and Chemical Terrorism course is to acquaint healthcare professionals with the overall concepts; raise the healthcare professional’s awareness of their role as a front line identifier of unusual trends in the community; and provide some familiarity with biological and chemical agent that may be used for terrorism.

Objectives

After completion of this course, the learner will be able to:

  • Discuss the vulnerability of the US to bioterrorist activity
  • Discuss the role of healthcare worker in identifying bioterrorism activity
  • Identify critical agents that terrorists might use
  • Discuss infection control practices for patient management
  • Identify the presentation and basic care recommendations for common biological agents that could be used in bioterrorist activity

Introduction

After the bioterrorist actions of September 11, 2001 on the World Trade Center and the discovery of a case of inhalational anthrax in Florida October 4, 2001, the practice of medicine changed in the United States. These attacks demonstrated how vulnerable the United States is to outside attacks.

Consequently, President Bush in his State of the Union address that year instructed leaders of the FBI, CIA, Homeland Security Department and the Department of Defense to develop a Terrorist Threat Integration Center to merge and analyze all types of threat information in a single location. His goal was to have the right people in the right places to protect our citizens.

How and when an act of biological or chemical terrorism might occur is unpredictable. Anthrax, botulinum toxin, ricin, plague, smallpox, tularemia and viral hemorrhagic fevers are on the top of the Center for Disease Control and Prevention's (CDC) list of biological weapons, considered "Category A" weapons most likely to be used in an attack. The acts could range from dissemination of aerosolized anthrax spores to food product contamination. Despite its unpredictable nature, the possibility of biological or chemical terrorism should not be ignored because the consequences of being unprepared are devastating. Thousands could die, but the fundamental motive would be to strike panic and fear in millions of people.

The United State’s vulnerability to the use of biological and chemical agents has been highlighted by recognition of substantial biological weapons development programs and arsenals in foreign countries, attempts to acquire or possess biological agents by militants, and high-profile terrorist attacks. The country’s local, state, and federal infrastructure is already strained as a result of other important public health problems and now has to deal with the dangers of terrorists.

The United States Government recognizes the significance of emergency preparedness and has committed substantial resources to the fight on terrorism. After the events of 9-11, the US government investigated the ability of hospitals to handle surge capacity in the event of a major disaster. To implement Bioterrorism Preparedness, funding became a necessity and consequently, it was approved by the Senate Appropriations Committee to provide $550 million for the Health Resources and Services Administration's Bioterrorism Hospital Preparedness program (AAMC Legislative and Regulatory Updates, June 2007). Further appropriations have been made to the preparations for bioterrorist attacks and consequentially the pandemic influenza in the amount of $8 billion (Preleg, Kellermann, & Golub, 2009).

Funds alone will not be effective against bioterrorism. After the 9-11 tragedy The CDC joined with law enforcement, intelligence, and defense agencies in addition to traditional CDC partners to address a national security threat.

A coalition developed after the 9-11 tragedy established a CDC Strategic Plan to implement Preparedness and Response to Biological and Chemical Terrorism. Steps for strengthening public health and healthcare capacity to protect the United States against these dangers were created and are updated as needed (CDC, 2006).

Vulnerability

The events of 9-11 have proven that no nation is free of terrorist activities. Incidents of terrorism involving bacterial pathogens, nerve gas, and chemical agents have demonstrated that the United States is vulnerable. Directions for preparing homemade agents are readily available at the touch of a button on the internet. Reports of arsenals of military bio-weapons raise the possibility that terrorists might have access to highly dangerous agents, which have been engineered for mass dissemination as small-particle aerosols. Such agents as the variola virus (smallpox) are highly contagious and often fatal. Responding to large-scale outbreaks caused by these agents will require the rapid mobilization of public health workers, emergency responders, and private health-care providers. Many hospitals are not prepared for a large scale surge of patients. One of the most vital steps for any hospital is to communicate with their community and practice preparing for large scale outbreaks using the Hospital Incident Command System based on the military model of command now being considered a standard with the Joint Commission who in 2009 dedicated an entire chapter to Life Safety and Emergency Management (McIsaac, 2008).

Most planning for emergency response to terrorism has been concerned with overt attacks like bombings. Chemical terrorism acts are likely to be overt because the effects of chemical agents are usually immediate and obvious. This type of attack elicits immediate response from police, fire, and EMS personnel.

Biological agent attacks are more likely to be covert. A biological agent in a public place will not have an immediate impact because of the delay between exposure and onset of illness after incubation. This presents different challenges and requires additional planning that involves the public health system in an emergency response. Physicians or other primary healthcare providers probably will identify the first casualties of a covert attack.

In the event of a covert release of a biological agent, like smallpox, patients will appear in doctors' offices, clinics, and emergency rooms during the first or second week. They will complain of symptoms that may initially appear as an ordinary virus. As the disease progresses, physicians may not recognize the disease because it is rare. The terrorist will be far away and the disease will be disseminated through the population by the time the first patients begin to die.

A short window of opportunity will exist between the time the first cases are identified and a second wave of the population becomes ill. During that brief period, public health officials will need to determine that an attack has occurred, identify the organism, and prevent more casualties. To save more lives there is a need for prompt diagnoses of unusual or suspicious health problems in animals as well as humans.

Many hazardous chemicals are used in industry (for example, chlorine, ammonia, and benzene). Others are found in nature (for example, poisonous plants). Chemical agents can also be delivered covertly through contaminated food or water. Some chemicals are from animal excretions. An example is the recent national outbreak of contaminated spinach. There were four fields farmed in San Benito and Monterey counties in California, that were irrigated with contaminated irrigation water, containing manure from cattle that were infected with a strain of E.Coli bacteria (strain O157:H7), that causes harm to the intestines. The most common effect of an E.Coli food poisoning is severe and often bloody diarrhea. Healthy adults generally recover within a week, but elderly or very young patients are most likely to develop complications, which may include kidney failure (Seasilver News Oct, 2006).

Preparedness

A large-scale attack with smallpox, aerosolized anthrax spores, a nerve gas, or a food borne biological or chemical agent would overwhelm the local and possibly the national public health system. Large numbers of patients, including both infected persons and people afraid they have the infection, would seek medical attention, with a corresponding need for medical supplies, diagnostic tests, and hospital beds. Emergency responders, healthcare workers, and public health officials might be at special risk. Everyday life would be disrupted as a result of widespread fear of contagion. Special planning and preparation is needed.

The National Bioterrorism Hospital Preparedness Program (NBHPP) enhances the ability of hospitals and health care systems to prepare for and respond to bioterrorism and other public health emergencies. Program priority areas include improving bed and personnel surge capacity, decontamination capabilities, isolation capacity, pharmaceutical supplies, and supporting training, education, and drills and exercises (Health Resources and Service Administration, 2007).

Preparedness for terrorist-caused outbreaks and injuries is an essential component of the U.S. public health surveillance and response system. This system is designed to protect the population against any unusual public health event like influenza pandemics, contaminated water supplies, or intentional dissemination of the plague. The epidemiologic skills, surveillance methods, diagnostic techniques, and physical resources required to detect and investigate unusual or unknown diseases are similar to those needed to identify and respond to an attack with a biological or chemical agent. However, additional preparation would be needed for mass casualties or the use of rare agents.

Detection, diagnosis, and mitigation of illness and injury caused by biological and chemical terrorism are complex processes. It involves numerous partners and activities and requires special emergency preparedness in all cities and states. CDC provides public health guidelines, support, and technical assistance to local and state public health agencies as they develop coordinated preparedness plans and response protocols.

CDC also provides self-assessment tools for terrorism preparedness, including performance standards, attack simulations, and other exercises. In addition, CDC encourages and supports applied research to develop innovative tools and strategies to prevent or mitigate illness and injury caused by biological and chemical terrorism.

The National Hospital Ambulatory Medical Care Survey is conducted annually by CDC's National Center for Health Statistics (NCHS) to determine training for terrorism related conditions in hospitals. The following was found:

Teaching hospitals were better trained than other hospitals for bioterrorism, and Joint Commission accredited hospitals had prepared more of their physicians, physician assistants, nurse practitioners, nurses and lab staff for such emergencies.

Eighty-eight percent of hospitals surveyed in 2003 and 2004 said their nurses had been trained in how to recognize and treat patients exposed to at least one of seven pathogens including smallpox, anthrax, plague, botulism, tularemia, viral encephalitis and hemorrhagic fever, and chemical or radiological attacks. Eighty-six percent of the clinical staff in hospitals with 24-hour emergency departments or outpatient clinics was trained to recognize and treat smallpox, and 82 percent were trained to recognize and treat anthrax infection.

Biodefense

Taking steps toward national biodefense most would consider being the responsibility of the government. Four main areas to consider would be threat awareness, prevention and protection, surveillance and detection, and response recovery (Homeland Security, n.d.). Although one might think all steps should fall under the scrutiny of the government, healthcare workers must be involved in all phases of the biodefense. Maintaining a clear line of communication is vital to the successful completion of each phase.

Early Detection

Early detection and control of biological or chemical attacks depends on a strong and flexible public health system at the local, state, and federal levels. Healthcare providers will invariably be the initial contact for those presenting with symptoms of the invading organism. Therefore, education of presenting signs and symptoms is imperative to protect both the patient and the healthcare provider. At first presentation the healthcare provider may not realize what he or she has been presented. Many of the symptoms of the Category A agents and diseases present with flu like symptoms before progressing to more severe illnesses. Only after having several patients present to triage or the doctor’s office with similar symptoms will the pieces begin to fall into place and the healthcare provider realize there is an epidemic at hand. The following are examples of what the healthcare provider might see to trigger thoughts of an epidemic.

  • increased disease incidence (e.g., within hours or days) in a normally healthy population,
  • an epidemic curve that rises and falls during a short period of time,
  • an unusual increase in the number of people seeking care, especially with fever, respiratory, or gastrointestinal complaints,
  • an endemic disease rapidly emerging at an uncharacteristic time or in an unusual pattern,
  • lower attack rates among people who had been indoors, especially in areas with filtered air or closed ventilation systems, compared with people who had been outdoors,
  • clusters of patients arriving from a single locale,
  • large numbers of rapidly fatal cases
  • any patient presenting with a disease that is relatively uncommon and has bioterrorism potential (e.g., pulmonary anthrax, tularemia, or plague).

Critical Agents

Potential biological and chemical agents are numerous, and the public health system must be equipped to quickly resolve crises that would arise from a biological or chemical attack. Agents that are highly contagious or that can be engineered for widespread dissemination via small-particle aerosols would have the largest impact. The CDC classifies the most important human pathogens into three categories, A, B, and C. Category A is the highest priority and includes the agents that are easiest to disseminate and transmit and cause the greatest public health crisis. Addendum A, at the end of this course, lists Category A agents and diseases with their method of spread, onset of symptoms, signs and symptoms, treatments, need for decontamination, and prevention. Category B agents are second-highest priority, are moderately easy to disseminate, and cause moderate morbidity and low mortality. Category C includes emerging pathogens that could potentially be developed into bio-weapons.

The preparedness efforts must be focused on these agents. The following are lists of critical biological and chemical agents (CDC, 2006).

Biological Agents (CDC, 2006)

Category A

High-priority agents include organisms that pose a risk to national security because they can be easily disseminated or transmitted person-to-person; cause high mortality, with potential for major public health impact; might cause public panic and social disruption; and require special action for public health preparedness. Category A agents includes:

  • Variola major (smallpox),
  • Bacillus anthracis (anthrax),
  • Yersinia pestis (plague),
  • Clostridium botulinum toxin (botulism),
  • Francisella tularensis (tularaemia),
  • Filoviruses,
    • Ebola hemorrhagic fever,
    • Marburg hemorrhagic fever, and
  • Arenaviruses,
    • Lassa (Lassa fever),
    • Junin (Argentine hemorrhagic fever) and related viruses.

Category B

The second highest priority agents include those that are moderately easy to disseminate; cause moderate morbidity and low mortality; and require specific enhancements of CDC's diagnostic capacity and enhanced disease surveillance.

Category B agents include:

  •   Coxiella burnetti (Q fever).
  •   Brucella species (brucellosis),
  •   Burkholderia mallei (glanders),
  •   Alphaviruses,
    •   Venezuelan encephalomyelitis,
    •   Eastern and western equine encephalomyelitis,
  •   Ricin toxin from Ricinus communis (castor beans),
  •   Epsilon toxin of Clostridium perfringens, and
  •   Staphylococcus enterotoxin B.

A subset of List B agents includes pathogens that are food or waterborne. These pathogens include but are not limited to:

  •   Salmonella species,
  •   Shigella dysenteriae,
  •   Escherichia coli O157:H7,
  •   Vibrio cholerae, and
  •   Cryptosporidium parvum.

 Category C

The third highest priority agents include emerging pathogens that could be engineered for mass dissemination in the future because of availability; ease of production and dissemination; and potential for high morbidity/mortality and major health impact.

Category C agents include

  • Nipah virus,
  • Hantaviruses,
  • Tickborne hemorrhagic fever viruses,
  • Tickborne encephalitis viruses,
  • Yellow fever, and
  • Multidrug-resistant tuberculosis.

Chemical Agents

The CDC has a key role in protecting the public's health in an emergency involving the release of a chemical that could harm people's health. A chemical emergency occurs when a hazardous chemical has been released and the release has the potential for harming people's health. Chemical releases can be unintentional, as in the case of an industrial accident, or intentional, as in the case of a terrorist attack. Hospitals generally are not prepared to perform decontamination for large numbers of patients involved in chemical exposures. Hospitals commonly expect the county emergency medical system to serve as the primary decontamination team, however, there will be those patients who self triage and show up at the emergency department after an exposure.

The primary concern at the time of presentation will be to not only keep the patient safe, but to keep the facility safe. Once the patient crosses the threshold of the facility, off gassing will create a situation for the organization requiring the area to be closed and all those in contact with the patient may need to be decontaminated or treated for injuries sustained. As a general rule, removing the patient’s clothing will remove approximately 85% of the contaminate. Remove the patient from the building, and alert the authorities in your organization of the situation in order to determine the best course of events for your organization.

Some chemicals that are hazardous have been developed by military organizations for use in warfare. Examples are nerve agents such as sarin and VX, mustards such as sulfur mustards and nitrogen mustards, and choking agents such as phosgene. It might be possible for terrorists to get these chemical warfare agents and use them to harm people.

Some chemicals could be made from everyday items such as household cleaners. These types of hazardous chemicals also could be obtained and used to harm people, or they could be accidentally released. Therefore, there is a need for prompt diagnoses of unusual or suspicious health problems in animals, plants, as well as humans.

Chemical agents that might be used by terrorists range from warfare agents to toxic chemicals commonly used in industry. Criteria for determining priority chemical agents include chemical agents already known to be used as weaponry; availability of chemical agents to potential terrorists; chemical agents likely to cause major morbidity or mortality; potential of agents for causing public panic and social disruption; and agents that require special action for public health preparedness.

Categories of chemical agents include (CDC, 2006):

Nerve agents,

  • tabun (ethyl N, N-dimethylphosphoramidocyanidate),
  • sarin (isopropyl methylphosphanofluoridate),
  • soman (pinacolyl methyl phosphonofluoridate),
  • GF (cyclohexylmethylphosphonofluoridate),
  • VX (o-ethyl-[S]-[2-diisopropylaminoethyl]-methylphosphonothiolate);

Blood agents,

  • hydrogen cyanide,
  • cyanogen chloride,

Blister agents,

  • lewisite (an aliphatic arsenic compound, 2-chlorovinyldichloroarsine),
  • nitrogen and sulfur mustards,
  • phosgene oxime;

Heavy metals,

  • arsenic,
  • lead,
  • mercury;

Volatile toxins,

  • benzene,
  • chloroform,
  • trihalomethanes;

Pulmonary agents,

  • phosgene,
  • chlorine,
  • vinyl chloride;

Incapacitating agents,

  • BZ (3-quinuclidinyl benzilate);

Pesticides, persistent and nonpersistent;

Dioxins, furans, and polychlorinated biphenyls (PCBs);

Explosive nitro compounds and oxidizers,

  • ammonium nitrate combined with fuel oil;

Flammable industrial gases and liquids,

  • gasoline,
  • propane;

Poison industrial gases, liquids, and solids,

  • cyanides,
  • nitriles; and

Corrosive industrial acids and bases,

  • nitric acid,
  • sulfuric acid.

Because of the hundreds of new chemicals introduced internationally each month, treating exposed persons by clinical syndrome rather than by specific agent is more useful for public health planning and emergency medical response purposes. Public health agencies and first responders might render the most aggressive, timely, and clinically relevant treatment possible by using treatment modalities based on syndromic categories like burns and trauma, cardio-respiratory failure, neurologic damage, and shock (Kahn, et al., 2000).

Preparing the nation to address these dangers is a major challenge. Early detection requires increased biological and chemical terrorism awareness among front-line healthcare providers because they are in the best position to report suspicious illnesses and injuries. Also, early detection will require improved communication systems between those providers and public health officials. State and local healthcare agencies must have enhanced capacity to investigate unusual events and unexplained illnesses. Diagnostic laboratories must be equipped to identify biological and chemical agents that rarely are seen in the United States. Fundamental to these efforts is comprehensive, integrated training designed to ensure core competency in public health preparedness and the highest levels of scientific expertise among local, state, and federal partners.

Infection Control Practices for Patient Management

Agents of bioterrorism are generally not transmitted from person to person and re-aerosolization of these agents is unlikely. All patients in healthcare facilities, including symptomatic patients with suspected or confirmed bioterrorism-related illnesses, should be managed utilizing Standard Precautions. Additional precautions are imperative for disease syndromes like pneumonic plague or smallpox to reduce the likelihood of transmission to others (APHL, 2006).

In small-scale events, routine facility patient placement and infection control practices should be followed. However, a large number of patients may not allow routine triage and isolation strategies. In that case, it will be necessary to apply practical alternatives. These may include grouping affected patients with similar symptoms into a designated section of a clinic or emergency department, or a designated ward or floor of a facility, or even setting up a response center at a separate building (APHL, 2006).

Many states have implemented the use of the START triage system categorizing the patient into four categories based on the acuity of their symptoms. This method of triage works well with field triage and can be implemented into the hospital initial triage system. With a surge of patients to triage from a large scale event, security will be required to either man the doors or go into a lock down and direct the patients to the central triage location. The best method of triage in a large scale event is to have a doctor-nurse-tagger team established to triage and track the patient as they present to triage. Radio communication with the incident command center is essential to follow the patient through the system.

Post Exposure Management

The need for decontamination depends on the suspected exposure and in most cases will not be necessary. The goal of decontamination after a potential exposure to a bioterrorism agent is to reduce the extent of external contamination of the patient and contain the contamination to prevent further spread. Decontamination should only be considered in instances of gross contamination. Decisions regarding the need for decontamination should be made in consultation with state and local health departments. Decontamination of exposed individuals prior to receiving them in the healthcare facility may be necessary to ensure the safety of patients and staff while providing care (CDC, 2006).

Decontamination will be done depending on the agent, the likelihood for re-aerosolization, or a risk associated with cutaneous exposure via clothing of exposed persons. After removal of contaminated clothing, patients should immediately shower with soap and water. Bathing patients with bleach solutions are unnecessary and should be avoided because of the potential harm to the patient. Clean water, saline solution, or commercial ophthalmic solutions are recommended for rinsing eyes. If indicated, after removal at the decontamination site, patient clothing should be handled only by personnel wearing appropriate personal protective equipment, and placed in an impervious bag to prevent further environmental contamination (CDC, 2006).

After a bioterrorism-related event, fear and panic can be expected from both patients and healthcare providers. Psychological responses following a bioterrorism event may include horror, anger, and panic, unrealistic concerns about infection, fear of contagion, paranoia, social isolation, or demoralization. Healthcare workers should be provided with bioterrorism readiness education, including discussions of potential risks and plans for protecting healthcare providers. Bioterrorism readiness was a necessity and required disaster drills on an ongoing basis (CDC, 2006), (APHL, 2006).

Response

A comprehensive public health response to a biological or chemical terrorist event involves epidemiologic investigation, medical treatment and prophylaxis for affected persons, and the initiation of disease prevention or environmental decontamination measures. CDC will assist state and local health agencies in developing resources and expertise for investigating unusual events and unexplained illnesses (CDC, 2006).

CDC maintains a national pharmaceutical stockpile to ensure the availability, procurement, and delivery of medical supplies and devices needed to respond to terrorist-caused illness or injury. If requested by a state health agency, CDC will deploy response teams to investigate unexplained or suspicious illnesses or unusual etiologic agents. CDC will also provide on-site consultation regarding medical management and disease control.

In the event of a confirmed terrorist attack, CDC will coordinate with other federal agencies in accord with Presidential Decision Directive (PDD) 39. This directive designates the Federal Bureau of Investigation as the lead agency for the crisis plan and charges the Federal Emergency Management Agency with ensuring that the federal response management is adequate to respond to the consequences of terrorism (APHL, 2006).

Description of Common Agents

The following are descriptions and recommendations for care of the most common biological agents that may be used in bioterrorist attacks. Theses recommendation come from APIC's publication Bioterrorism readiness plan: A template for healthcare facilities available at http://www.cdc.gov/ncidod/hip/Bio/13apr99APIC-CDCBioterrorism.PDF). Additional information can be obtained from emergency Number at the CDC Emergency Response Office, 770/488-7100.

Anthrax

Anthrax is an acute infectious disease caused by Bacillus anthracis, a spore forming, and gram-positive bacillus. Associated disease occurs most frequently in sheep, goats, and cattle, which acquire spores through ingestion of contaminated soil. Humans can become infected through skin contact, ingestion, or inhalation of B. anthracis spores from infected animals. Person-to-person transmission of inhalational disease does not occur. Direct exposure to vesicle secretions of cutaneous anthrax lesions may result in secondary cutaneous infection.

Human anthrax infection occurs in three forms: pulmonary, cutaneous, or gastrointestinal, depending on the route of exposure. Of these forms, pulmonary anthrax is associated with bioterrorism exposure to aerosolized spores. Clinical features for each form of anthrax include:

Pulmonary

  • non-specific prodrome of flu-like symptoms follows inhalation of infectious spores,
  • possible brief interim improvement, two to four days after initial symptoms,
  • abrupt onset of respiratory failure and hemodynamic collapse, possibly accompanied by thoracic edema and a widened mediastinum on chest radiograph suggestive of mediastinal lymphadenopathy and hemorrhagic mediastinitis
  • gram-positive bacilli on blood culture, usually after the first two or three days of illness, and
  • treatable in early prodromal stage (mortality remains extremely high despite antibiotic treatment if it is initiated after onset of respiratory symptoms).

Cutaneous

  • local skin involvement after direct contact with spores or bacilli, commonly seen on the head, forearms or hands, localized itching,
  • followed by a papular lesion that turns vesicular that within 2-6 days develops into a depressed black eschar, and
  • usually non-fatal if treated with antibiotics.

Gastro-intestinal

  • abdominal pain, nausea, vomiting, and fever following ingestion of contaminated food, usually meat,
  • bloody diarrhea,
  • hematemesis,
  • gram-positive bacilli on blood culture, usually after the first two or three days of illness, and usually fatal after progression to toxemia and sepsis.

The incubation period following exposure to B. anthracis ranges from 1day to 8 weeks (average 5days), depending on the exposure route and dose:

  • 2-60 days following pulmonary exposure,
  • 1-7 days following cutaneous exposure, and
  • 1-7 days following ingestion.

There is an inactivated, cell-free anthrax vaccine, but availability is limited.

Standard Precautions are used for the care of patients with infections associated with B anthracis. Placement in a private room is not necessary. Airborne transmission of anthrax does not occur. Skin lesions may be infectious, but requires direct skin contact only.

The risk for re-aerosolization of B. anthracis spores appears to be extremely low in settings where spores were released intentionally or were present at low or high levels. In situations where the threat of gross exposure to B. anthracis spores exists, cleansing of skin and potentially contaminated fomites (e.g. clothing or environmental surfaces) may be considered to reduce the risk for cutaneous and gastrointestinal forms of disease. The plan for decontaminating patients exposed to anthrax may include the following:

  • instructing patients to remove contaminated clothing and store in labeled, plastic bags,
  • handling clothing minimally to avoid agitation,
  • instructing patients to shower thoroughly with soap and water (providing assistance if necessary),
  • decontaminating environmental surfaces using an EPA-registered, facility-approved sporicidal/germicidal agent or 0.5% hypochlorite solution (one part household bleach added to nine parts water).

Botulism

Clostridium botulinum is an anaerobic gram-positive bacillus that produces a potent neurotoxin, botulinum toxin. In humans, botulinum toxin inhibits the release of acetylcholine, resulting in characteristic flaccid paralysis. C. botulinum produces spores that are present in soil and marine sediment throughout the world. Food borne botulism is the most common form of disease in adults. An inhalational form of botulism is also possible. Botulinum toxin exposure may occur in both forms as agents of bioterrorism.

Food borne botulism is accompanied by gastrointestinal symptoms. Inhalational botulism and foodborne botulism are likely to share other symptoms including:

  • responsive patient with absence of fever.
  • symmetric cranial neuropathies (drooping eyelids, weakened jaw clench, difficulty swallowing or speaking),
  • blurred vision and diplopia due to extra-ocular muscle palsies,
  • symmetric descending weakness in a proximal to distal pattern (paralysis of arms first, followed by respiratory muscles, then legs),
  • respiratory dysfunction from respiratory muscle paralysis or upper airway obstruction due to weakened glottis, and
  • no sensory deficits.

Botulinum toxin is generally transmitted by ingestion of toxin-contaminated food. Aerosolization of botulinum toxin has been described and may be a mechanism for bioterrorism exposure. Neurologic symptoms of foodborne botulism begin 12– 36 hours after ingestion. Neurologic symptoms of inhalational botulism begin 24- 72 hours after aerosol exposure.

A pentavalent toxoid vaccine has been developed by the Department of Defense. This vaccine is available as an investigational new drug. Completion of a recommended schedule (0, 2, 12 weeks) has been shown to induce protective antitoxin levels detectable at 1-year post vaccination. Routine immunization of the public, including healthcare workers, is not recommended.

Standard Precautions are used for the care of patients with botulism. Patient-to-patient transmission of botulism does not occur. Patient room selection and care should be consistent with facility policy. Principles of Standard Precautions should be generally applied to the management of patient-care equipment and environmental control

Suspicion of even single cases of botulism should immediately raise concerns of an outbreak potentially associated with shared contaminated food. In collaboration with CDC and local /state health departments, attempts should be made to locate the contaminated food source and identify other persons who may have been exposed. Any individuals suspected to have been exposed to botulinum toxin should be carefully monitored for evidence of respiratory compromise.

Contamination with botulinum toxin does not place persons at risk for dermal exposure or risk associated with re-aerosolization. Therefore, decontamination of patients is not required.

Plague

Plague is an acute bacterial disease caused by the gram-negative bacillus Yersinia pestis, resulting in lymphatic and blood infections (bubonic and septicemia plague). A bioterrorism-related outbreak may be expected to be airborne, causing a pulmonary variant, pneumonic plague. Clinical features of pneumonic plague include:

  • fever, cough, chest pain,
  • hemoptysis,
  • muco-purulent or watery sputum with gram-negative rods on gram stain, and
  • radiographic evidence of bronchopneumonia.

Plague is normally transmitted from an infected rodent to man by infected fleas. Bioterrorism-related outbreaks are likely to be transmitted through dispersion of an aerosol. Person-to-person transmission of pneumonic plague is possible via large aerosol droplets.

The incubation period for plague is normally 2 – 8 days if due to fleaborne transmission. The incubation period may be shorter for pulmonary exposure (1-3 days).

Formalin-killed vaccine exists for bubonic plague, but has not been proven to be effective for pneumonic plague. It is not currently available in the United States. Routine vaccination requires multiple doses given over several weeks and is not recommended for the general population. Post-exposure immunization has no utility.

For pneumonic plague, Droplet Precautions should be used in addition to Standard Precautions. Droplet Precautions should be maintained until patient has completed 72 hours of antimicrobial therapy. Minimize dispersal of droplets by placing a surgical-type mask on the patient when transport is necessary. Principles of Standard Precautions should be generally applied to the management of patient-care equipment and for environmental control.

The risk for re-aerosolization of Y. pestis from the contaminated clothing of exposed persons is low. In situations where there may have been gross exposure to Y. pestis, decontamination of skin and potentially contaminated fomites (e.g. clothing or environmental surfaces) may be considered to reduce the risk for cutaneous or bubonic forms of the disease. The plan for decontaminating patients may include:

  • instructing patients to remove contaminated clothing and storing in labeled, plastic bags,
  • handling clothing minimally to avoid agitation, and
  • instructing to patients to shower thoroughly with soap and water (providing assistance if necessary).

Smallpox

Smallpox is an acute viral illness caused by the variola virus. Smallpox is a bioterrorism threat due to its potential to cause severe morbidity in a nonimmune population and because it can be transmitted via the airborne route. A single case is considered a public health emergency.

Acute clinical symptoms of smallpox resemble other acute viral illnesses, such as influenza. Skin lesions appear, quickly progressing from macules to papules to vesicles. Other clinical symptoms to aid in identification of smallpox include:

  • 2-4 day, non-specific prodrome of fever, myalgias,
  • rash most prominent on face and extremities (including palms and soles) in contrast to the truncal distribution of varicella,
  • rash scabs over in 1-2 weeks, and
  • In contrast to the rash of varicella, which arises in crops, variola rash has a synchronous onset.

Smallpox is transmitted via both large and small respiratory droplets. Patient-to-patient transmission is likely from airborne and droplet exposure, and by contact with skin lesions or secretions. Patients are considered more infectious if coughing or if they have a hemorrhagic form of smallpox.

The incubation period for smallpox is 7-17 days; the average is 12 days. Unlike varicella, which is contagious before the rash is apparent; patients with smallpox become infectious at the onset of the rash and remain infectious until their scabs separate (approximately 3 weeks).

A live-virus intra-dermal vaccination is available for the prevention of smallpox. Since the last naturally acquired case of smallpox in the world occurred more than 20 years ago, routine public vaccination has not been recommended. Vaccination against smallpox does not reliably confer lifelong immunity. Even previously vaccinated persons should be considered susceptible to smallpox. Vaccination is generally contraindicated in pregnant women, and persons with immunosuppression, HIV–infection, and eczema, who are at risk for disseminated vaccinia. The last known case of smallpox in the world was reported in Somalia in 1977 and has since been eradicated. Therefore, vaccinations have ceased worldwide.

For patients with suspected or confirmed smallpox, Airborne Precautions. Airborne Precautions are used for patients known or suspected to be infected with microorganisms transmitted by airborne droplet nuclei of evaporated droplets containing microorganisms that can remain suspended in air and can be widely dispersed by air currents. Airborne Precautions require healthcare providers and others to wear respiratory protection when entering the patient room. Appropriate respiratory protection is based on facility selection policy; but, must meet the minimal NIOSH standard for particulate respirators, N95. Patients suspected or confirmed with smallpox require placement in rooms that meet the ventilation and engineering requirements for Airborne Precautions, which include:

  • monitored negative air pressure in relation to the corridor and surrounding areas,
  • 6 - 12 air exchanges per hour,
  • appropriate discharge of air to the outdoors, or monitored high efficiency filtration of air prior to circulation to other areas in the healthcare facility, and
  • the door that must remain closed.

A key to the success of a bioterrorism preparation plan is communication. Healthcare facilities without patient rooms appropriate for the isolation and care required for Airborne Precautions should have a plan for transfer of suspected or confirmed smallpox patients to neighboring facilities with appropriate isolation rooms.

Limit the movement and transport of patients with suspected or confirmed smallpox to essential medical purposes only. When transport is necessary, minimize the dispersal of respiratory droplets by placing a mask on the patient, if possible. Patient decontamination after exposure to smallpox is not indicated.

Conclusion

Investment in national defense ensures preparedness and acts as a deterrent against hostile acts. Likewise, investment in the public health system provides the best civil defense against bioterrorism. Healthcare facilities, Fire departments, and emergency organizations nationwide are working together practicing for emergencies and developing ways to provide emergency care when acts of violence affect our most precious gifts, the lives of our people.

The CDC's plan includes the development of a public health communication infrastructure, a multilevel network of diagnostic laboratories, and an integrated disease surveillance system. These components will improve our ability to investigate rapidly and control public health threats that emerge. Tools developed in response to terrorist threats serve a dual purpose. They help detect rare or unusual disease outbreaks and respond to health emergencies, including naturally occurring outbreaks or industrial injuries that might resemble terrorist events in their unpredictability and ability to cause mass casualties.

Hospitals are forming communication networks to share information, and practice community emergency drills utilizing strategies which are designed to help our citizens survive.

The goal is to improve our preparedness and communication, our surveillance and detection and become more responsive and skillful in containment of hazardous materials of mass destruction. Listed below are resources that one can use to reach the goals.

Bioterrorism Guides:

  • AAMC Legislative and Regulatory Updates, June 2007
  • Arizona Department of Health Services Zebra Manual 2007. A Reference Handbook for Bioterrorism Agents
  • APIC and CDC. Bioterrorism Readiness Plan. A Template for Healthcare Facilities
  • California Department of Health Services. California Hospital Bioterrorism Response Planning Guide 2005
  • CDC. Influenza Pandemic Preparedness
  • HHS and CDC. Pan Flu Business Checklist
  • HHS and CDC. Pan Flu Business Checklist. Spanish version
  • Homeland Security Council. National Strategy for Pandemic Influenza
  • Homeland Security. National Incident Management System guide. (NIMS) 2006
  • Pandemic Flu Guides 2006

References

APHA. (2007). Resource Guide: Federal Assistance Programs for Terrorism retrieved June 20, 2007 from http://www.apha.org/advocacy/priorities/issues/rebuilding/legislativebuildresourceguide.htm.

APIC Bioterrorism Task Force and CDC Hospital Infections Program Bioterrorism Working Group (1999). Bioterrorism readiness plan: A template for healthcare facilities. Retrieved May 5, 2007 from http://www.cdc.gov/ncidod/hip/Bio/13apr99APIC-CDCBioterrorism.PDF.

Arizona Department of Health Services Zebra Manual. (2007). A Reference Handbook for Bioterrorism Agents, retrieved June 20, 2007 from www.azdhs.gov/phs/edc/edrp/index.htm.

CDC. (n.d.). Bioterrorism agents/diseases. Retrieved September 6, 2009, from http://emergency.cdc.gov/agent/agentlist-category.asp

CDC. (2006). Preparation & Planning, Public Health Emergency Preparedness, retrieved June 20, 2007 from www.bt.cdc.gov/planning.

CDC. (2007). Morbidity and Mortality Weekly Report. Retrieved May 10, 2007 from http://www.bt.cdc.gov/agent/agentlist.asp.

CDC. (2007). Training for Terrorism-Related Conditions in Hospitals: United States, 2003-2004. Retrieved June 20, 2007 from www.cdc.gov/nchswww.cdc.gov/nchs.

Federal Emergency Management Agency. (1999). Federal response plan. Washington, DC: Government Printing Office. Retrieved May 10, 2007 from http://www.fema.gov/r-n-r/frp.

FEMA. (2006). Resource Guide: Federal Assistance Programs for Terrorism Preparedness 2006. Retrieved June 20, 2007 from http://training.fema.gov/EMIWeb/

Homeland Security. (n.d.). Homeland Security Presidential Directive 10: Biodefense for the 21st Century. Homeland Security Presidential Directive 10: Biodefense for the 21st Century. Retrieved September 6, 2009, from DHS: Homeland Security Presidential Directive 10: Biodefense for the 21st Century database.

Kahn, C., Levitt, A., & Sage, M. (2000). Biological and chemical terrorism: strategic plan for preparedness and response: Recommendations of the CDC strategic planning workgroup, April 21, 2000 / MMWR, 49(RR04); 1-14 Retrieved May 10, 2007 from http://www.cdc.gov/mmwr/preview/mmwrhtml/rr4904a1.htm .

McIsaac, J. H. (2008). Hospital preparation for disasters. ASA Refresher Courses in Anesthesiology, 36(1), 99-108.

NIMS and Homeland Security Field Guides. (2006). retrieved June 20, 2007 from
www.bepress.com/cgi/viewcontent.cgi?article=1321&context=jhsem

OPHEPR; Office of Emergency Preparedness & Response. (2007). Zebra Manual. ADHS Reference Handbook for Bioterrorism Agents: About the Bureau: Personal Preparedness. Copyright 2007 Arizona Department of Health Services. Retrieved June 20, 2007 from http://www.azdhs.gov/phs/edc/edrp/index.htm.

OSHA. (2007). Safety and Health Topics: Emergency Preparedness and Response. Retrieved June 20, 2007 from http://www.osha.gov/SLTC/emergencypreparedness/index.html.

OSHA. (2007). Federal Register Notice 70:4027-4030, 2006 retrieved June 20, 2007 from www.osha.gov/SLTC/emergencypreparedness/index.html

Preleg, K., Kellermann, A. L., & Golub, R. M. (2009). Enhancing hospital surge capacity for mass casualty events. The Journal of the American Medical Association, 302(5), 565-567.