Study Points

Bioterrorism: An Update for Healthcare Professionals

Course #91763 - $20 • 5 Hours/Credits

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  • Participation Instructions
    • Review the course material online or in print.
    • Complete the course evaluation.
    • Review your Transcript to view and print your Certificate of Completion. Your date of completion will be the date (Pacific Time) the course was electronically submitted for credit, with no exceptions. Partial credit is not available.
  1. The role of the medical practitioner in the event of a bioterrorism attack includes all of the following, EXCEPT:

    UNDERSTANDING AND RESPONDING TO BIOTERRORISM

    What is the role of the practicing medical professional in the event of a bioterrorism attack and what is the expected response? This may be broken down into three simple steps: Identify, Report, and Refer [3].

    IDENTIFY

    • Be aware of the signs and symptoms of a bioterror agent

    • Know the appropriate tests to request

    • Have an awareness of possible differential diagnoses

    REPORT

    • Be able to contact the appropriate agencies

    • Initiate the preprogrammed response by public and government agencies

    REFER

    • Be able to refer victims of possible bioterror to bioterrorism experts or specialists

    • Refer any media requests to these individuals as well

    The CDC and other public health agencies recommend being extra vigilant with patients, sharing information with them, allaying their fears, and helping them to understand the limits of the bioterror agents. Conversely, these organizations strongly advise against:

    • Prescribing antibiotics inappropriately

    • Stockpiling antibiotics

    • Recommending gas masks

    • Unnecessarily alarming patients or peers

    It is important to remember that no single antibiotic will protect against all potential bacterial agents. The duration of protection from antibiotics is short. Indiscriminate use will waste supplies, induce drug resistance, and may lead to adverse effects. In addition, the organism used in an attack may have been engineered to be resistant to the commonly prescribed antibiotics [3].

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  2. What was the most successful recent bioterror attack prior to 2001?

    BIOTERRORISM IN RECENT HISTORY

    The most successful bioterrorist attack in the United States before 2001 occurred in Oregon in 1984, when members of the Rajneesh commune attempted to influence the outcome of an election by infecting the salad bars of 10 restaurants with Salmonella spp. bacteria. They believed that if the local citizens were inflicted with diarrhea, they would not be able to vote. More than 750 people were sickened by the attack, but if this had been done with volatized anthrax spores, there could have been hundreds of fatalities [4,5]. The lead medical investigator admitted that public health officials were unprepared to deal with an attack of greater magnitude.

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  3. In what year did U.S. Secretary of Defense William Cohen announce that all U.S. military troops would be immunized against anthrax?

    BIOTERRORISM IN RECENT HISTORY

    General antiterrorism training efforts intensified following the New York City World Trade Center bombing in 1993. The Tokyo subway sarin nerve agent release and Oklahoma City federal building bombing, both occurring in 1995, stimulated an additional increase in awareness of bioterrorism. In November 1997, Secretary of Defense William Cohen announced that all U.S. military troops would be immunized against anthrax as a precaution [6]. Additionally, the disclosure that a sophisticated offensive biologic warfare program existed in the former Soviet Union along with information obtained after the 2001 attacks on New York and Washington, D.C., reinforced the need for increased training and education.

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  4. The CDC has designated three classes of possible bioterrorism diseases/agents. They are categorized according to

    TYPES OF AGENTS

    The CDC has defined three categories of possible bioterror agents and diseases. Agents are categorized according to their priority as risks to national security [7].

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  5. All of the following are considered Category A agents by the CDC, EXCEPT:

    TYPES OF AGENTS

    Representative Category A Agents

    • Anthrax (Bacillus anthracis)

    • Botulism (Clostridium botulinum toxin)

    • Plague (Yersinia pestis)

    • Smallpox (variola major)

    • Tularemia (Francisella tularensis)

    • Viral hemorrhagic fevers (e.g., Ebola)

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  6. Dispersion of weapons of bioterror can occur by

    TYPES OF AGENTS

    Despite the very different properties of bacteria, viruses, and toxins, most biologic and chemical agents that can be used as weapons share some common characteristics. The most important characteristic is the ability of the agent to be dispersed in aerosols, with a particle size of 1–5 microns. These particles can remain suspended (in certain weather conditions) for hours and, if inhaled, will penetrate the distal bronchioles and terminal alveoli of victims. Particles larger than 5 microns would tend to be filtered out in the upper airway [9]. An indoor or domed stadium is a high-risk potential target for aerosolized biologic or chemical weapon attack.

    Many of these agents may also be dispersed by contamination of foodstuffs, as was the case with the 1984 Rajneesh Salmonella attacks, although the effect is localized. It is estimated that less than 1 gram of botulinum toxin could poison 100,000 individuals if added to the commercial milk supply; nearly 600,000 could be poisoned with 10 grams [10]. Parasites (e.g., tapeworm eggs) could presumably be placed into a salad bar, salsa bar, or drinking water dispensers, and symptoms would not be seen until weeks or years after becoming infected [11]. This type of bioterrorist attack could be carried out for many months without being detected. Even after presentation of symptoms, diagnosis may not be rapid because many healthcare professionals are unfamiliar with tapeworm infections [11].

    Waterborne dispersion is also a concern; however, the threat of harming large numbers of people by dispersing biologic or chemical agents into reservoirs is often mitigated by water treatment. Nonetheless, there have been successful bioterrorist attacks on drinking water supplies. One such incident occurred in Edinburgh, Scotland, in 1990, when nine individuals in the same apartment complex were infected with Giardia[11]. The apartment complex had an unsecured water supply, which was purposefully contaminated with feces. A bioterrorist might tap into and contaminate a large building's water supply, which is unlikely to undergo additional purification.

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  7. Two examples of bacterial agents for biowarfare are

    BACTERIAL AGENTS

    Bacterial agents are among the most probable sources of bioterror and include anthrax, brucellosis, plague, tularemia, and Q fever. They are generally easily accessible and fairly simple to spread. Bacteria can cause diseases in humans and animals by two possible means: by invasion of tissues or by production of toxins that cause a pathologic response. In many cases, pathogenic bacteria possess both properties. Fortunately, this group of agents often responds to specific therapy with antibiotics. The following sections will examine the more common bacterial agents in detail.

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  8. The anthrax skin infection first appears as a

    BACTERIAL AGENTS

    The anthrax skin infection begins as a raised pruritic lesion or papule that resembles an insect bite. Within one to two days, the lesion develops into a fluid-filled vesicle, which ruptures to form a painless ulcer, 1–3 cm in diameter, with a necrotic area in the center [2,14]. Pronounced edema is often associated with the lesions because of the release of an edema-producing toxin by B. anthracis. The lymph nodes in the area may become involved and enlarged. The incubation period in humans is usually one to seven days but could be prolonged to almost two weeks [2,14]. To describe the lesion in more detail, picture a painless macular eruption that appears within two to five days, most commonly on an exposed portion of the body. The lesion progresses from a red macule to a pruritic papule, then to a single vesicle or ring of vesicles. This is followed by a depressed ulcer and finally a black necrotic eschar that falls off within 7 to 10 days. There is edema associated with the eschar but usually no permanent scarring of the affected area. The cutaneous form of anthrax progresses to systemic disease in 10% to 20% of the cases, with a fatality rate of up to 20% if untreated [2,14]. Laboratory tests of blood products are usually normal if the disease is not disseminated. The systemic symptoms of cutaneous anthrax infection include fever, headache, regional lymph node involvement, and myalgia [2].

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  9. The Working Group on Civilian Biodefense suggests use of which antibiotic for primary pneumonic plague?

    BACTERIAL AGENTS

    Clinical suspicion of plague should prompt immediate intravenous antibiotic treatment. Gentamicin and fluoroquinolones are typically first line therapy in the United States [29,39]. Aminoglycosides (streptomycin, gentamycin) and fluoroquinolones (ciprofloxacin, levofloxacin) are bactericidal against the plague bacillus. Doxycycline and chloramphenicol are bacteriostatic but effective. Historically, streptomycin was the treatment of choice for plague, but the advent of equally effective and less toxic aminoglycosides has meant that streptomycin is no longer widely available in the United States. In a retrospective analysis of 50 patients reported between 1985 and 1999, gentamicin alone or in combination with doxycycline was as effective as streptomycin for treatment of human plague [111]. The Working Group suggests adding chloramphenicol (25 mg/kg IV, four times daily) for patients with plague meningitis. Supportive therapy includes maintaining fluid levels with IV fluids and monitoring of the patient's hemodynamic status [29]. The duration of antibiotic treatment is 10 to 14 days, or until 2 days after fever subsides. Oral therapy may be substituted when the patient has improved. If fever recurs after a favorable initial therapeutic response, the patient may have secondary infection, drug fever, or a suppurative bubo that requires incision and drainage [34]. The CDC provides guidance regarding the specific antibiotic regimens for adults and children, including postexposure prophylaxis and links to additional information on antimicrobial therapy of plague [39].

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  10. Tularemia was studied for use as a biologic weapon by

    BACTERIAL AGENTS

    Tularemia is one of the most infectious diseases known; as few as 10 F. tularensis bacteria can cause disease in humans [41,42]. Consequently, it has been widely exploited as a weapon of bioterror. The Japanese studied it for use between 1932 and 1945, the Soviet Union may have used it on the Eastern Front in World War II, and the United States possessed a 450 kg weaponized dry-form stockpile until the use of biologic arsenals was eliminated [41,43]. The most probable dissemination of F. tularensis as a weapon would be as an aerosol [42]. In fact, epidemics have occurred after harvests in Northern Europe, where the organism became aerosolized and infected hundreds of people. The organism is quite hardy and can survive for prolonged periods of time in water, mud, and animal carcasses. Even frozen, F. tularensis is highly infectious, and laboratory workers have become infected while inspecting incubation plates [41]. It is estimated that a 50 kg aerosolized release over a 5 million inhabitant metropolitan area could infect 250,000 people and kill nearly 20,000 [43].

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  11. Smallpox is primarily a possible threat as a bioweapon because

    VIRUSES

    Variola can be used as a biologic weapon in aerosol form or deposited onto surfaces. Because smallpox vaccination of the general population in the United States was discontinued in the 1980s, the use of the smallpox virus as a weapon constitutes a large threat, especially because certain countries may be harboring stockpiles of the agent.

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  12. In the case of a smallpox outbreak, vaccination priority should be given to all of the following high-risk groups, EXCEPT:

    VIRUSES

    The "ring vaccination" strategy will be the first-line strategy in a smallpox emergency. It vaccinates the contacts of patients with confirmed smallpox and also those who are in close contact with those contacts. This may include [75,76]:

    • Face-to-face close contacts (≤6.5 feet or 2 meters) or household contacts (without contraindications to vaccination) to smallpox patients after the onset of the smallpox patient's fever, and nonhousehold members with three or more hours of contact with a case with rash

    • Persons exposed to the initial release of the virus (if the release was discovered during the first generation of cases and vaccination may still provide benefit)

    • Persons involved in the direct medical care, public health evaluation, or transportation of confirmed or suspected smallpox patients

    • Laboratory personnel involved in the collection and/or processing of clinical specimens from suspected or confirmed smallpox patients

    • Other persons who have a high likelihood of exposure to infectious materials (e.g., personnel responsible for hospital laundry, waste disposal, and disinfection)

    • Personnel involved in contact tracing and vaccination; quarantine/isolation or enforcement; or law-enforcement interviews of suspected smallpox patients

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  13. In addition to supportive care, IV ribavirin may offer benefit for treating which of the following virus types that cause hemorrhagic fevers?

    VIRUSES

    VIRAL HEMORRHAGIC FEVERS (VHFs) OF BIOWARFARE INTEREST

    Virus TypeName and SpeciesRegionVectorIncubation Period (Days)Treatment
    ArenaviridaeArgentine HF (Junin)South AmericaRodent7 to 14Ribavirina and supportive
    Bolivian HF (Machupo)South AmericaRodent9 to 15Ribavirina and supportive
    Brazilian HF (Sabia)South AmericaRodent7 to 14Ribavirina and supportive
    Venezuelan HF (Guanarito)South AmericaRodent7 to 14Ribavirina and supportive
    Lassa Fever (Lassa)West AfricaRodent5 to 16Ribavirina and supportive
    Unnamed HF (Whitewater Arroyo)North AmericaRodentUnknownRibavirina and supportive
    BunyaviridaeCrimean-Congo HFAfrica, Asia, Middle East, Eastern EuropeTick3 to 12Ribavirina and supportive
    Rift Valley HFAfrica, Middle EastMosquito2 to 6Ribavirina and supportive
    FiloviridaeEbola HFAfricaUnknown2 to 21Supportive
    Marburg HFAfricaUnknown2 to 14Supportive
    FlaviviridaeDengue HFAfrica, Asia, Pacific, AmericasMosquitoUnknownSupportive
    Kyanasur Forest DiseaseIndiaTick2 to 9Supportive
    Omsk HFCentral AsiaTick2 to 9Supportive
    Yellow FeverAfrica, AmericasMosquito3 to 6Supportive
    aIntravenous ribavirin is available as an investigational new drug (IND) in the United States.
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  14. In the United States, there is a licensed vaccine available for

    VIRUSES

    In the United States, there are no licensed vaccines for any of the VHFs, with the exception of yellow fever; some additional VHF vaccines are available in other countries (e.g., Candid #1, an Argentine hemorrhagic fever vaccine available in Argentina). The yellow fever vaccine, 17D, was developed when outbreaks caused widespread disease among workers and military forces in endemic areas [9]. The vaccine is a live attenuated preparation that is very effective when administered to travelers and those in endemic areas [77]. It is not available in large amounts and would not be useful in preventing disease in multiple areas or in large populations. It would also not be useful in a postexposure scenario because yellow fever has an incubation period significantly shorter than the time it takes for the inoculated person to develop the neutralizing antibodies [77].

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  15. Botulinum toxins are produced by

    TOXINS

    Botulinum toxins gained widespread recognition as a result of the introduction of botulinum Type A (Botox) into the field of cosmetology. The toxins have been medically significant for many years due to the serious and often fatal consequences of ingesting improperly canned or bottled foods. Botulinum toxins are proteins produced by the anaerobic bacterium Clostridium botulinum and consist of seven separate but related neurotoxins, denoted A through G. All of the strains produce similar effects when ingested or inhaled. They are among the most toxic compounds known, with serotype A having an estimated toxic dose of 0.001 mcg/kg of body weight oral or injected and 0.07 mcg/kg of body weight inhaled [84]. These neurotoxins act by binding at the presynaptic nerve terminals and at the cholinergic autonomic sites. They also block acetylcholine transmission, causing skeletal muscle weakness and paralysis as well as bulbar palsies [85,86]. If effectively dispersed in aerosol form, 1 gram of botulinum toxin has the potential to kill more than 1 million people [87].

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  16. An orally ingested dose of how little botulinum toxin serotype A is toxic?

    TOXINS

    Botulinum toxins gained widespread recognition as a result of the introduction of botulinum Type A (Botox) into the field of cosmetology. The toxins have been medically significant for many years due to the serious and often fatal consequences of ingesting improperly canned or bottled foods. Botulinum toxins are proteins produced by the anaerobic bacterium Clostridium botulinum and consist of seven separate but related neurotoxins, denoted A through G. All of the strains produce similar effects when ingested or inhaled. They are among the most toxic compounds known, with serotype A having an estimated toxic dose of 0.001 mcg/kg of body weight oral or injected and 0.07 mcg/kg of body weight inhaled [84]. These neurotoxins act by binding at the presynaptic nerve terminals and at the cholinergic autonomic sites. They also block acetylcholine transmission, causing skeletal muscle weakness and paralysis as well as bulbar palsies [85,86]. If effectively dispersed in aerosol form, 1 gram of botulinum toxin has the potential to kill more than 1 million people [87].

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  17. Ricin poisoning results in all of the following symptoms, EXCEPT:

    TOXINS

    The gastrointestinal signs and symptoms of oral ricin poisoning include abdominal pain, vomiting, gastrointestinal hemorrhage with bloody diarrhea, fluid and electrolyte depletion, hypotension, tachycardia, and eventually hepatic, splenic, pancreatic, and renal necrosis [47]. The incubation period depends on the amount ingested and is usually four to six hours, although some cases have been seen with symptoms beginning within 15 minutes [8]. As noted, the initial dose can be as low as 1 mg, but this is not commonly seen. Death can occur in three to five days from organ failure and hypovolemic shock [47]. However, the death rate for ricin (or at least castor bean) ingestion is less than 2% and depends greatly on the dose [11].

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  18. Which of the following statements regarding infection control in cases of ricin poisoning is TRUE?

    TOXINS

    There is no person-to-person transmission of ricin, and secondary transmission of aerosols from victims of ricin poisoning is not documented [47,102]. If ricin is released as an aerosol, careful decontamination will be necessary to prevent re-aerosolization. Ricin-infected patients' clothing and personal effects should be removed and disposed of according to safety regulations. Whenever possible, this should take place prior to arrival at a healthcare facility [98]. Exposed skin can be decontaminated with soap and water and a 0.1% sodium hypochlorite solution, which inactivates the ricin toxin [47]. Eyes may be irrigated with a saline solution.

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  19. A possible clue to a biowarfare or terrorist attack is

    DETECTING AND MANAGING A BIOLOGIC ATTACK

    Other possible clues to a biologic warfare or terrorist attack include [1,85]:

    • High disease rates among exposed individuals

    • A naturally vector-borne disease occurring in an area that lacks the appropriate vectors for normal transmission

    • More than one epidemic occurring at the same time

    • Suspicious activity or discovery of a potential delivery system, such as a spray device

    • Higher morbidity and mortality than normally expected for a disease

    • A rapidly increasing disease incidence (hours or days) in a normally healthy population

    • An epidemic curve rising and falling in a short period of time

    • Unusual increase in people with fever or respiratory symptoms seeking treatment

    • An endemic disease emerging quickly at an unusual time or geographic location

    • Lower attack rates among people who had been indoors compared to those outdoors

    • Clusters of patients arriving from a single locale

    • Large numbers of rapidly fatal cases

    • Any patient presenting with an uncommon disease, such as pneumonic anthrax, tularemia, or plague

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  20. Included in a disaster plan should be processes for

    APIC BIOTERRORISM READINESS PLAN

    Every medical facility should have a plan in place to delineate how to deliver care in the event of a large-scale bioterrorist event. This disaster plan should be created with input from the infection control committee, administration, emergency department, laboratory directors, and nursing directors [1]. Processes for triage, safe housing, and care for potentially large numbers of affected individuals should be included in the bioterrorism plan. The needs of the facility will vary based on the size of the regional population served. Triage and management planning for large-scale events may include the following [1]:

    • Establishing communication networks and lines of authority required to coordinate on-site care

    • Planning for cancellation of nonemergency services and procedures

    • Identifying sources able to supply vaccines, immune globulin, antibiotics, and antitoxins

    • Planning for efficient evaluation and discharge of patients

    • Developing discharge instructions for noninfectious patients

    • Identifying sources for additional medical equipment and supplies

    • Planning for the allocation or re-allocation of scarce equipment

    • Determining the ability to handle a sudden increase in the number of cadavers on site

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  • Participation Instructions
    • Review the course material online or in print.
    • Complete the course evaluation.
    • Review your Transcript to view and print your Certificate of Completion. Your date of completion will be the date (Pacific Time) the course was electronically submitted for credit, with no exceptions. Partial credit is not available.