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Biological, chemical and radiological terrorism.

After completing this overview of terrorism, readers should be able to:

* Describe the early signs and symptoms of a covert terrorist attack.

* Discuss the radiographic signs of exposure to bioterrorism agents.

* List likely chemical, biological and radiological agents of terrorism.

* Categorize biological agents of terror by their Centers for Disease Control (CDC) threat level.

* Explain the relevance of syndromic surveillance in terrorism preparedness.

This article is a Directed Reading. See the quiz at conclusion.

The world has changed. The threat of nuclear Armageddon has waned with the passing of the Cold War, but the threat of a small-scale nuclear attack by terrorists is greater than ever. Smallpox no longer ravages developing nations, but it already may have been weaponized by rogue states. On the heels of the tragedies of September 11, 2001, the United States was subjected to anthrax attacks delivered through the postal system--the first wave of systematic, widespread and deadly biological terrorism in America since British forces intentionally distributed smallpox-inoculated blankets to indigenous people during the French and Indian Wars in 1763. The 2001 postal service anthrax attacks resulted in relatively few fatalities and little economic disruption, but they convincingly demonstrated the nation's woeful lack of preparation for terrorist attacks with biological agents.

At least 10 countries currently are capable of disseminating biological or chemical weapons. (1) Terrorist organizations are believed to be independently seeking nuclear material from the former Soviet Union for use against the United States and our western allies. Research laboratories, radiology, units and epicenters of emerging infections diseases are likely additional targets for terrorists' attempts to acquire raw material for weapons of mass destruction (WMD). Just as KGB agents posed as epidemiologists and virologists to obtain hemorrhagic fever viruses from gravely ill patients in Africa during Ebola and related disease outbreaks during the 1980s, (2) representatives of terrorist organizations can be expected to try to acquire biological, chemical and radiological agents wherever opportunities arise.

The "Bioshield" plan--a 10-year research initiative announced in President Bush's 2003 Stale of the Union address--hastens review of emergency treatments not vet approved by the Food and Drug Administration (FDA). Of the $6 billion allotted to the Bioshield initiative, $900 million is earmarked for vaccines and medicines in the event of a biological terrorist attack. Unfortunately, terrorism readiness has been undermined by reductions in nonbioterrorism spending. One controversial example was the reduction in funding for the Centers for Disease Control's global emerging infections monitoring program. (3)

The Bioterrorism Act of 2003 calls on federal agencies and state and local authorities to prepare bioterror response plans. The act enhances controls of dangerous chemicals and biological agents and increases protection of food, drug and drinking water supplies. It also calls for the integration of planning among federal and local law enforcement, emergency response, disaster management and medical response institutions.

Suddenly, medical personnel must become familiar with concepts like community-wide emergency preparedness and unified command systems, as well as the signs and symptoms of exposure to obscure infectious agents and chemical weapons. All health care personnel must become adept at spotting the early signs of biological, chemical and radiological terrorism; recognizing institutional unpreparedness; and setting aside concerns for friends and loved ones to respond to the mass casualties that could result from a terrorist WMD attack.

Meeting the challenge of terrorism's threat requires a 2-fold strategy: prevention and preparation. The goal of prevention is to identify terrorists and their plans before those plans can be executed. The goal of preparedness is to minimize the loss of life in terrorist attacks, reducing terrorism's ability to achieve its political goals and diminishing its power and appeal. Radiologic technologists have important roles to play both in preventing and preparing for WMD terrorism.

The first priority is prevention, which involves improved intelligence gathering and increased vigilance by personnel at institutions likely to be targeted by terrorists seeking germs, radiological materials, chemical weapons or their precursors.

Equally important is community preparedness for WMD terrorism. Should prevention strategies fail, local, state and federal coordination among law enforcement, emergency response, disaster management and medical response personnel will play a crucial role in saving lives in the aftermath of any mass casualty terrorist attack. Radiologic technologists are on one of the front lines of terrorism prevention every day, and will be among the first responders to any WMD terrorist attack, helping to evaluate trauma victims and even identify the nature of the attack.

Despite the urgency of the situation 2 years after September 11, one recent assessment concluded that in most American communities "there is no community emergency plan, nor program, nor system." (4) Furthermore, "it is no longer sufficient to develop disaster plans and dust them off if a threat appears imminent," that report warned. "Rather, a system of preparedness across communities must be in place every day." (4)

Instead of responding to this state of affairs, many health cave administrators and personnel, along with the general public, have lapsed into a dangerous complacency about WMD terrorism, resulting in the "confused state of nonreadiness" terrorists await. (4,5) Recent assessments bare found health care institutions poorly prepared tot WMD attacks. (5) Despite nearly $6 billion lot public health system preparedness in the 2003 federal budget, (3) most hospitals have vet to receive substantial funding for terrorism preparedness. Most lack the specialized equipment, decontamination rooms, sufficient stocks of antibiotics and response plans to contend effectively with chemical or biological terrorist attacks. (6) All hospitals are required to have disaster plans, but few facilities are truly ready for the surge of cases from a terrorist WMD attack. (6)

Indeed, the need for an increased capacity for medical response to mass-casualty terrorism comes at a time when the nation is supremely underprepared for such a challenge. (7,8) There are critical shortages of nurses and emergency room personnel, for example, and we have significantly fewer hospitals mad emergency rooms than was the case just a few years ago. (4) Between 1993 and 1996, the number of acute-care hospital beds in the nation declined by 9%. (5) Nor are clinicians adequately ready for WMD terrorist attacks. Faced with increasing financial constraints, American hospitals have reduced stockpiling of supplies in favor of "just in time" purchasing, leaving inadequate stocks of medicines and equipment in respond to WMD terrorism. (5) In view of these shortages, we must rapidly develop high-technology, burden-sharing solutions such as telemedicine, which will allow consultation with experts and institutions outside the immediately affected region.

Every hospital employee must become familiar with the medical challenges of mass casualty terrorism. This Directed Reading introduces WMDs that may he employed by terrorists; describes WMD effects and treatments; and reviews prevention, preparedness and medical response to WMD terrorism.

Biological Terrorism

Signs that a WMD terrorism attack has occurred range front the sudden arrival of large numbers of patients with similar symptoms at emergency rooms to a single patient with an "out-of-place" disease. Depending on the type of weapon used, a WMD attack can be either immediately evident or covert. Chemical attacks or a nuclear detonation cause immediate mass casualties, and patients suffer from overt, rapid-onset symptoms. Biological weapons, on the other hand, can be used covertly, with delayed symptom onsets reflecting the disease organism's incubation period, the magnitude of initial infection and individual variations in immunity. (9) Unlike chemical or nuclear attacks, biological attacks have the added danger of affected individuals unknowingly spreading the disease before they become symptomatic.

Short of a nuclear bomb attack, biological weapons are by far the most serious terrorist threat. Bioterror agents have no typical or unique symptom signatures. Treatment options are few, and the cryptic and delayed onset of symptoms may create panic and social unrest. They are, in short, ideal weapons for terrorists. (10)

Historical Background

Humanity's checkered history of waging war and terror with disease organisms is poorly documented and the subject of denial and controversy. In the 1400s, Pizarro distributed smallpox-contaminated cloth to indigenous people in South America as part of a genocidal campaign. As mentioned earlier, the British followed suit in 1763, using smallpox-inoculated blankets to trigger epidemics among indigenous tribes during the French and Indian Wars. Fearing similar attacks during the American Revolution, General George Washington ordered his men to immunize themselves with live smallpox viruses taken from infected patients' lesions, a practice that infected 1 in 200 of his men with full-blown smallpox. (11)

During World War II Germany infected livestock with anthrax and Pseudomonas bacteria before shipping the animals to the United States, but the gambit failed to cause an epidemic in America. A German saboteur was arrested during World War I in Iraq (then Mesopotamia) after infecting thousands of mules with glanders, a chronic and debilitating disease caused by Pseudomonas mallei. However, it was only in the years leading up to World War II, after the 1925 Geneva Protocol forbade chemical and biological warfare, that the modern era of biological weaponry began.

In 1932, Imperial Japan's Unit 731 was founded. Throughout World War II, prisoners of war were unwilling subjects of Unit 731's experiments and biological weapons development. At least 1000 prisoners were killed in experiments with anthrax, botulism, cholera, gangrene, plague and other infectious diseases. In 1940, Japanese aircraft dropped plague-contaminated rice and fleas over Shesien, a city in the Chinese province of Chekiang. Bubonic plague soon broke out, the first recorded incidence of the disease in the region. The Japanese waged another dozen plague attacks against other Chinese cities in subsequent months. (11)

In 1979, 77 Soviet citizens in the city of Sverdlovsk tell in with inhalational anthrax; 66 suffered agonizing deaths. The Soviet government claimed at the time that tainted meat was to blame, but Western experts rejected this explanation, noting that inhalational anthrax results from breathing anthrax spores and cannot be caused by eating tainted meat. In 1992, Russian President Boris Yeltsin formally admitted that the outbreak was the result of an apparently accidental release of weaponized anthrax from a secret biowarfare laboratory, an illegal facility under the 1972 Biological Weapons Convention.

According to Soviet defectors, as many as 60,000 scientists and technicians were developing biological weapons at more than 40 laboratories in the former Soviet Union before the regime's collapse. (11,12) President Yeltsin curtailed offensive biological weapons research in 1992, throwing thousands of bioweapons experts out of work. Underemployed biological weapons scientists, like unemployed Russian nuclear weapons scientists, are an ongoing source of concern for Western governments because of the threat of disseminating their expertise to terrorists.

In 1984 followers of Bhagwan Shri Rashneesh distributed Salmonella in the town of Antelope, Ore, in an effort to reduce voter turnout before an election. They sprinkled the Salmonella on supermarket produce, restaurant salad bars and other locations. No one died, but 751 people became ill.

In the month following the New York and Washington, DC, terrorist attacks on September 11, 2001, the postal system was used to deliver anthrax spores to the offices of media personalities, senators and citizens throughout the country. Within 7 weeks, 22 cases of anthrax were diagnosed. Because most cases were cutaneous rather than pulmonary, only 5 of the victims died. This most recent use of biological weapons was the wake-up call that spurred government to prepare for a more severe, future bioterror attack.

Signs oft Bioterror Attack And Categories of Bioterror Agents

The "ideal" bioterrorism agent is highly lethal, drug resistant and deliverable in aerosols or from person to person. Probable agents of choice for bioterrorists include smallpox virus and hemorrhagic fever viruses, and bacterial agents such as botulinum, tularemia and anthrax. Of potential bioterrorism agents, anthrax and smallpox are most likely to result in mass casualties. (10,13) In addition to the specific signs and symptoms described later in this article, general indicators of a bioterror attack include:

* Increased occurrences of nonfood poisoning hospitalizations over a few hours or days.

* Symptoms of respiratory anthrax or plague (which, when acquired from nature, are rarely respiratory inflections).

* Patients who share geographic proximity or whose homes or workplaces appear to represent wind distribution of a disease agent.

In 1999 the Centers for Disease Control (CDC) organized an expert panel to identify critical biological agents, organisms or their toxins that would pose the greatest threat to life and national security if used in a terrorist attack. (14) (See Table 1.) Category A agents pose the greatest threat, due to ease of dissemination, likelihood of person-to-person transmission, high mortality rate and likelihood of disrupting society and the economy. Category A agents require major public health preparedness planning. Category B agents are of less concern because of lower mortality and ease of dissemination, but they still present a significant threat of use by terrorists. Category C organisms are emerging pathogens that may represent a terrorist threat in the near future because they could be genetically engineered for mass dissemination and would pose a high risk of mass mortality once used.

The CDC established the Laboratory Response Network to confirm the presence of biological weapons in tissue samples. Laboratories included in the network are ranked in an ascending A-D ranking system for their ability to safely handle and test for different types of biological agents. Level A labs, the most common, are capable of the most simple testing, whereas Level D labs have biological safety level (BSL) 4 testing facilities capable of safety containing the deadliest infectious agents in the world. Most clinical and hospital laboratories are ranked as Level A facilities. Specimens and cultures from patients suspected of having smallpox or hemorrhagic fever viruses should be examined only in Level D labs. Anthrax, botulism and plague specimens should be routed to public health labs and clinical labs with Level A or Level B rankings (BSL-2), while tularemia cultures should be handled only at facilities with Level B and higher rankings (BSL-3 or BSL-4).

Anthrax

Because of its recent use as a bioterror agent and its lethality anthrax is of utmost concern to terrorism experts. When anthrax bacteria deplete local nutrient supplies, they form spores that can survive for decades. One report estimated that up to 3 million deaths could result from the release of 100 kg of anthrax spores in a heavily populated city. (15) Perhaps the tone piece of good news about this bioterror agent is that it is not transmitted from person to person.

Bacillus anthracis is a rod-shaped bacterium that causes 3 forms of anthrax infection: cutaneous, inhalational and gastrointestinal. Cutaneous anthrax is the most common form of the disease when anthrax is contracted from infected animals. Small cuts in the skin become locally infected, causing swelling and subsequent ulceration, as dying tissue turns black. Gastrointestinal anthrax, a rare form of the disease, occurs when contaminated meat is not properly cooked.

Of the 3 forms of anthrax infection, inhalational is the most deadly. (16) Anthrax spores are 2 to 6 [micro]m in diameter, making them prone to deep respiratory tract inhalation. (17) In nature, spores tend to clump and bind to soil, reducing the risk of aerosolization and inhalation. However, in the United States, the former Soviet Union and elsewhere, anthrax spores have been weaponized by adding fine silica to reduce their electrostatic charge and clumping behavior, thereby facilitating spores' ability to form aerosols. The 2001 postal system anthrax attacks involved weaponized spores.

Inhaled spores are transported through the lymphatic system to the mediastinal lymph nodes, where they germinate for up to 2 months after inhalation. Mature anthrax cells excrete several toxins that kill victims' cells and tissues. The spores used in the 2001 anthrax attacks had an incubation period of 4 to 6 days. Before the 2001 attacks, inhalational anthrax was so rare in the United States that only 18 cases had been diagnosed nationwide in the entire preceding century. Most of what we thought we knew about inhalational anthrax was learned from the 1997 Sverdlovsk outbreak in the former Soviet Union. However; the 2001 cases did not always follow that pattern. For example, half of Sverdlovsk victims developed hemorrhagic anthrax meningitis, a complication not seen in the 2001 attack's victims. (9) Also, 60% of the victims in the 2001 anthrax attacks survived, a significantly higher survival rate than the 14% observed in the 1979 Sverdlovsk outbreak. (18)

* Precautions

Person-to-person anthrax infection has not been documented. The primary risk to medical personnel is exposure to surgical instruments after invasive procedures or autopsy. (14) Depending on the exposure route and magnitude, weaponized anthrax spores might be present on a patient's skin, hair or clothing. Therefore, standard precautions should be observed during patient care (eg, gowns, gloves and masks), and patients ideally should be kept in isolation.

* Clinical Presentation

To identify inhalational anthrax early, health care personnel must be extremely vigilant. Initial symptoms vary and are easily mistaken for more benign respiratory infections. This creates diagnostic delays that contribute to the high mortality rate associated with the disease. (16,19-20)

In the post-September 11 anthrax attacks, for example, several postal workers employed at the Washington, DC, central postal facility, became infected. Of 2 surviving patients who had inhalational anthrax, one developed low-grade fever with chills, cough and flu-like malaise 3 days before admission to hospital. The second patient developed increasingly severe headaches tot 3 days, and then nausea, chills and night sweats, but no coughing, on the day of hospital admission. (21) These disparate symptoms resulted from infection by genetically identical strains of anthrax, highlighting the variability among victims. Both of the patients had abnormal chest radiographs, and after computed tomography (CT) scans of the chest revealed mediastinal adenopathy in both patients, the symptoms were recognized as probable inhalational anthrax. This preliminary diagnosis subsequently was confirmed with blood culture and genetic Jesting of the cultured bacteria.

Inhalational anthrax typically presents as a 2-stage illness. (9) The first stage involves indistinct, flu-like symptoms such as fever, respiratory distress, cough, headache, vomiting, rigors, weakness and pain in the abdomen and chest. One, a few or all of these symptoms may be present, and this stage may last a few hours or several days. In a review of 10 cases in the 2001 attack, all 10 inhalational anthrax patients initially presented with chills or fever, fatigue and malaise; 7 of the patients presented with increased perspiration; and only 1 patient had a productive cough. (18)

The second or fulminant stage may appear immediately after the first or after a period of apparent improvement. Onset usually is abrupt, involving fever, respiratory distress, increased perspiration and symptoms of shock. Stridor (high-pitched, noisy breathing) may occur when mediastinal lymph nodes hemorrhage, causing airway obstruction. Delirium and hallucinations are indicative of secondary brain infection (ie, anthrax meningoencephalitis).

* Diagnostic Imaging

Suspected cases of inhalational anthrax can he confirmed preliminarily with chest radiographs in both the first and second stages of infection. (17) Unlike clinical presentations, radiographic imaging can yield at least 2 "classic" findings: mediastinal widening and pleural effusions. (16) All of the inhalational anthrax patients from the 2001 postal system attacks had abnormal chest radiographs. Seven or 8 of the 10 had radiological signs of pleural effusion and mediastinal widening. (18) Diffuse consolidation consistent with pneumonia also was seen in several patients. Abnormalities are not always immediately evident on chest radiographs, however. In 2 patients, radiographs initially were interpreted as normal. Abnormalities were recognized only upon re-examination, after chest CT exams revealed abnormalities.

Posteroanterior (PA) chest radiographs typically reveal hilar prominence and mediastinal widening. (22,23) (See Fig. 1.) This is often more marked in the right paratracheal region. Other signs of inhalational anthrax are multiple, poorly defined and patchy opacities in the lung parenchyma, (18,24) peribronchial opacities (17) and airspace disease. (23)

[FIGURE 1 OMITTED]

Chest CT scans more clearly reveal abnormalities associated with inhalational anthrax than do radiographs. (See Fig. 2.) CT scans without contrast of patients from the 2001 postal system attacks consistently showed enlarged, high-attenuation mediastinal lymph nodes and extremely dense hilar lymph nodes. (14) CT images also yielded superior visibility of lymphatic system involvement, which appears as parenchymal opacities distributed about the bronchial airways.

[FIGURE 2 OMITTED]

In one of the victims of the 2001 attacks, gastrointestinal symptoms were so significant that the patient was wrongly believed to he suffering from an intra-abdominal condition. Chest radiographs and CT scans of the chest and abdomen subsequently revealed pleural effusions and mediastinal edema--signs of inhalational anthrax--and that diagnosis was confirmed. (25) The patient died, however, leading some to argue that in areas experiencing an anthrax outbreak, patients should be treated for anthrax until that diagnosis has been excluded. (25)

Anthrax meningoencephalitis is a fare secondary hemorrhagic anthrax infection of the brain. In contrast axial CT scans, meningoencephalitis appears as diffuse hemorrhages and mild enlargement of the ventricles. T2-weighted magnetic resonance (MR) images show diffuse dark signal intensities at sites of hemorrhage. (26) When patients hallucinate or exhibit other neurological symptoms, brain CT scans are indicated.

* Treatment

Suspected anthrax cases should be treated immediately, even before the diagnosis is confirmed. (9) Before the 2001 postal system attacks, cases of inhalational anthrax were universally filial when treatment was begun after significant symptoms developed. Of the 11 inhalational cases in the 2001 postal system attack, however, only 5 (45%) were fatal. (14,18) Survivors almost certainly benefited from early detection and aggressive antibiotic intervention and supportive care. (14)

The CDC advises initial therapy with doxycycline or ciprofloxacin antibiotics, followed by penicillin in patients without penicillin allergy, or tetracyclines and erythromycin in penicillin-allergic patients. (27)

Smallpox

Smallpox was eradicated from human populations in 1977. Vaccination was curtailed in the United States in 1972 and worldwide in 1980. (9) Smallpox is the single most dangerous potential bioterror agent; it is readily transmitted from person to person, has a high infectivity rate and a fatality rate of 30% (3% in vaccinated individuals). Like anthrax, it can be widely disseminated as an aerosol.

* Precautions

Smallpox patients should he quarantined immediately with strict respiratory isolation precautions. People who have unprotected contact with the patient should be placed in negative-pressure respiratory isolation rooms with air filtration and monitored for 2 weeks. (9) If possible, patients with smallpox should be quarantined away from the hospital to reduce the risk of disease spread. In major outbreaks, quarantine and care in patients' homes may be necessary if hospital resources are overwhelmed.

All hospital personnel should observe standard, airborne and contact precautions strictly. Contaminated laundry and waste material should he disposed in biohazard bags for autoclaving or incineration. All surfaces in contaminated rooms should he cleaned with disinfectants. Personnel who come into contact with patients should receive the smallpox vaccination.

* Clinical Presentation

Variola virus causes smallpox when it lands in the upper respiratory tract's mucous membrane. After initial proliferation in the epithelial cells of the respiratory tract, infection spreads to the lymph system, and from there to skin, intestines, lungs and the brain. (28) Early symptoms begin to appear 12 to 14 days after exposure. (14) These include fever, rigors, nausea and vomiting, malaise, delirium and rash. Two to 3 days after initial symptoms appear, patients begin to develop lesions, typically in the mouth. Dense rashes become large pustules. Symptoms are confused easily with chickenpox (Varicella) if smallpox is not suspected. Unlike chickenpox, smallpox lesions occur primarily on the face and extremities, including the palms of the hands. All smallpox lesions develop in the same stages, whereas chickenpox lesions are at different stages of development. (9) Some smallpox patients develop delirium.

Two severe forms of smallpox account for up to 10% of all cases. These are flat-type and hemorrhagic-type smallpox, both of which cause pulmonary edema believed to be associated with diffuse damage to the aveoli, the lungs' smallest airways. In flat-type smallpox. which is evidenced by flat and slowly developing lesions, 95% of unvaccinated patients die. Hemorrhagic-type smallpox causes mucous membrane hemorrhaging in the earliest stages of infection, killing patients before skin lesions appear.

Heart failure resulting from inflammatory response throughout the body kills most victims. Definitive diagnosis involves virus isolation and genetic analysis. In outbreaks, diagnoses are made using clinical symptoms.

* Diagnostic Imaging

Respiratory symptoms appear late in smallpox infection. A mild pulmonary form of smallpox without skin lesions sometimes occurs in vaccinated individuals after exposure to patients who have full-blown smallpox. This is called "smallpox handler's disease" and usually is seen in health care personnel. (17) Smallpox handler's disease appears up to 12 days after exposure. Chest radiographs show poorly defined nodular opacities in the upper lungs.

Rarely, smallpox symmetrically invades the arm bones and joints, particularly the elbows. Bilateral radiographs reveal extensive inflammation of the outer (ie, periosteal) bone in the forearms, seen as radiolucent patches.

* Treatment

After an outbreak is identified, large-scale vaccination should be undertaken immediately, including individuals who were vaccinated before 1972. Smallpox vaccine is distributed by the CDC, mad can prevent or reduce the severity of smallpox even several days after exposure. For symptomatic patients, however there is no specific treatment other than supportive care. The antimicrobial drug cidofovir has been shown Io control smallpox virus in petri dishes (9) and to reduce mortality in primates infected with monkeypox, hut no human clinical data are available.

Plague

Plague is caused by the bacterium Yersinia pestis, which in nature is transmitted to humans and other mammals through the bites of infected fleas. Plague causes bubonic, pneumonic or septicemic disease. Bubonic plague is the most common form and is believed to be the infection responsible tot the Black Death that decimated Europe in the 1300s. It causes lymphatic system infection and lymph node necrosis, followed by heart failure. Bioterrorism using plague in aerosol form probably would result in pneumonic plague because victims would inhale the bacteria rather than be infected by a fleabite. Normally, pneumonic plague is a complication of bubonic or septicemic plague, so the appearance of pneumonic plague in patients without primary bubonic or septicemic forms of the disease should he treated as evidence of a bioterrorist attack. (9)

* Precautions

Respiratory droplets can spread plague; therefore, patients with plague should be isolated until day 4 of antibiotic therapy. Standard and body fluid precautions should he observed, and patients should be isolated in negative-pressure morns and treated with droplet precautions (ie, the use of eye shields, masks, gowns and gloves). (14)

Traditionally, it has been recommended that those who have been in close contact with patients should follow respiratory isolation precautions for at least the first 48 hours of antibiotic therapy. Alternatively, exposed asymptomatic individuals should be monitored for lever or cough for 7 days after exposure to a plague patient, but isolation is not considered necessary.

* Clinical Presentation

Symptoms typically occur 2 to 4 days after exposure and include fever, productive cough and perceived breathing abnormalities. Patients also may present with abdominal pain, nausea and diarrhea. Coughing, particularly when it produces bloody sputum, is more indicative of plague than anthrax, which has symptoms that overlap with plague.

* Diagnostic Imaging

Chest radiographs of patients with pneumonic plague vary, lint tend to reveal nodular opacities and diffuse air-space disease that very rarely results in the formation of large cavities. Consolidated pneumonia also is seen, typically extensively, within one or more lobes of the lung. (14)

In rare instances, mediastinal adenopathy is quite pronounced. However, neither hilar adenopathy nor mediastinal adenopathy is a consistent finding in plague. Lymph node inflammation (bubo) sometimes is seen.

* Treatment

Plague vaccine was deemed ineffective and discontinued in 1999; it is now unavailable. Antibiotic therapy with streptomycin or, alternatively, gentamicin is used to treat plague. If hospital or clinic supplies of these antibiotics are depleted, doxycycline can be used as an alternative treatment. (9) Postexposure IV prophylaxis with these antibiotics is indicated for individuals who exhibit fever during a plague outbreak. In infants, increased respiratory rate alone is an indication for antibiotic therapy. (9)

Tularemia

The bacterium Francisella tularensis causes tularemia. Nonterrorist cases are caused by human contact with infected animals' body fluids or bites from insects that previously fed on infected animals. The United States weaponized tularemia in the 1950s and 1960s.

* Precautions

Quarantine and isolation are unnecessary with tularemia patients, although standard precautions should be observed strictly. Clothing, bedding and equipment should be disinfected with heat and chemical disinfectants.

* Clinical Presentation

Incubation can last from 1 to 21 days after exposure, but typically lasts 3 to 5 days. There are 6 natural forms of tularemia in humans: typhoidal, ulceroglandular; glandular, oculoglandular, oropharyngeal and pneumonic. Of these, typhoidal and pneumonic tularemia are most likely to result from bioterrorist attacks delivered as aerosols. A recent outbreak of pneumonic tularemia followed an accidental aerosolization during lawn mowing. (29)

Typhoidal tularemia patients present with fever, weight loss and prostration but not lymphadenopathy. Respiratory discomfort, pneumonia and productive or nonproductive cough also may be observed. Typhoid tularemia kills 35% of untreated patients. Pneumonic tularemia is a complication or secondary type of typhoid tularemia, seen in as ninny as 80% of typhoid tularemia patients. (14)

* Diagnostic Imaging

Three quarters of patients present with bronchopneumonia, and one third exhibit patchy opacities, pleural effusions and lymphadenopathy. It is not known whether typhoidal tularemia is associated with distinct radiographic signs that could be used to differentiate it from other types of tularemia. (17) Air-space disease can become pronounced and form cavities. Diaphragm tenting results from pleural effusion.

In the lawn mower outbreak mentioned above, some patients' chest radiographs initially appeared normal. However, radiographs taken 1 to 2 days after symptom onset showed multifocal or lobar infiltration. Mediastinal adenopathy did not occur, but some patients exhibited mild hilar adenopathy. (17,30)

* Treatment

Traditionally, antibiotic therapy with streptomycin was the treatment of choice for tularemia. However the United States developed streptomycin-resistant tularemia in the 1950s, and other nations are thought to possess drug-resistant swains. State-sponsored terrorism, therefore, may tree strains that do not respond to classic tularemia treatment. Victims of tularemia bioterrorism should be treated with W gentamicin or ciprofloxacin, changing to oral ciprofloxacin or streptomycin only after symptoms have improved.

Live tularemia vaccine has few if any adverse side effects and prevents onset of typhoidal tularemia in some patients. (14) Ciprofloxacin or doxycycline also may provide protection after exposure, if administered within 24 hours of inhalation.

Hemorrhagic Fevers

Hemorrhagic fever viruses are highly infectious, and there are many types of hemorrhagic fever diseases. (See Table 2.) Symptoms vary, but fatalities all result from extensive end-stage hemorrhaging. Terrorist organizations and foreign governments have attempted to weaponize these viruses. (2,14)

* Precautions

Viral hemorrhagic fevers are transmitted as infectious aerosols and are notoriously difficult to contain. Aerosol and droplet precautions should be observed meticulously. Patients should be isolated in negative-pressure rooms entered through adjoining disinfection rooms in which negative air pressure also is maintained. Medical personnel should wear high efficiency particulate air (HEPA) filtered positive-pressure masks and impermeable Level A protective suits, if available. (14) Radiologic technologists are likely to come in contact with patients very early in symptomatic infections; whenever hemorrhagic viruses are suspected, head-to-toe garment coverage and protective respiratory equipment should be used. Anyone who comes in unprotected contact with infected patients or their blood, body secretions, clothing or bedding should he monitored for symptoms for 12 days.

* Clinical Presentation

Symptoms of hemorrhagic fever vary considerably from patient to patient, based on infection route, viral strain, virulence and the patient's general health. Incubation periods also vary, but typically last 5 to 10 days. Hemorrhagic viruses target different organs. Late- or end-stage symptoms are related to uncontrolled internal bleeding caused by markedly increased permeability of the microvasculature. Seizures indicate impending death. Any patient who presents with severe fever and internal bleeding or vascular involvement should be tested for hemorrhagic fever diseases.

Lassa fever patients initially present with cough, chest pain, abdominal pain and vomiting. Only 20% exhibit mucosal hemorrhaging. South American hemorrhagic fevers are associated with lower back pain, fever and malaise, followed by photophobia, hypotension, eye pain and lymphadenopathy.

The most infamous hemorrhagic viruses are Marburg and Ebola. Onset symptoms include severe fever, headache and myalgia, followed by chest pain, abdominal pain, vomiting, diarrhea, coughing, photophobia and, in some cases, pancreatitis. Subsequent symptoms include hemorrhaging, purple dots on the skin (petechiae) and extensive black or purple bruise-like hemorrhages.

* Diagnostic Imaging

Except for American hantavirus, diagnostic imaging is of limited use in hemorrhagic fevers. For example, patients infected with South American strains generally have normal chest radiographs. However, as terminally ill patients with Argentine hemorrhagic fever become superinfected with bacteria, some develop lobar opacities.

Early in the course of American hantavirus pulmonary syndrome, chest radiographic findings include marked interstitial edema and subpleural edema. Interstitial edema and diffuse air-space disease are common in hantavirus, but uncommon in anthrax, smallpox, plague, tularemia and other hemorrhagic fevers. (17) In severe cases of hantavirus, chest radiographs reveal bilateral alveolar filling within 48 hours. Hilar and mediastinal adenopathy are absent in all hemorrhagic fevers, as are segmental and lobar consolidation.

* Treatment

There is no treatment for hemorrhagic fevers. Supportive care is provided to maintain critical organ function.

Botulism

Botulinum is the deadliest known biological toxin. It disables motor neurons, causing paralysis. Botulism occurs naturally when toxins excreted by bacteria are absorbed through mucosal surfaces or cuts. Botulinum bioterrorism would likely involve aerosol attacks or food poisoning.

* Clinical presentation

Twelve to 72 hours after exposure, patients present with symmetric paralysis of muscles, resulting loss of muscle tone, dry mouth and blurred vision. Symptoms of the hind brain region called the medulla, also known as "bulbar" symptoms, occur early in disease onset. Fever is absent.

* Treatment

Recovery can occur when the neurons' axons grow new synaptic terminals to replace injured ones. Treatment is supportive. Paralysis of respiratory muscles may require assisted mechanical ventilation. Despite dilated or fixed pupils, the patient remains aware of his or her surroundings and senses are intact. Medical personnel should speak to patients and reassure them about their eventual recovery of muscular function. With proper supportive care, 94% of patients survive. (9) The U.S. Army has a potential antitoxin that may be made available to health care providers in the event of a bioterrorist attack.

Chemical Terrorism

In April 1915, during World War I, German forces released an estimated 160 tons of chlorine gas upwind of British and allied positions in Belgium, choking more than 5000 soldiers to death and wounding 15000 with chemical damage to the respiratory tract. Later that year, phosgene was used and found to be 10 times more deadly. Mustard agents--colorless, odorless sulfide-based poisons that destroy the body's skin, mucous membranes and lungs--also were treed extensively in World War I, and again in the Iran-Iraq war of 1980 to 1988.

Tabun, the first nerve gas, was developed by Nazi scientists during the 1930s. Sarin and soman were developed in the late 1930s and early 1940s. Although sarin became the weapon of choice for modern-day terrorists, chemical weapons were not used by European powers in World War II except for Mussolini's use of nitrogen mustards against Ethiopian soldiers. Japanese forces used mustard gas and lewisite in their invasion of China.

Collectively, nerve gases are known as "G" agents (for German). In the 1950s more stable versions of these weapons, called "V" agents, were developed. VX is more stable and potent than sarin, for example. It also is far more environmentally persistent, remaining in the soil and air up to a month after its release. (9)

The era of chemical weapons terrorism, arrived in 1989, when the Iraqi government unleashed satin on the Kurdish inhabitants of Halabja, killing several thousand people in minutes, In 1994 and 1995, the religions cult Aura Shinrikyo launched the first mass non-government-sponsored chemical terrorism attacks on civilians. Sarin chemical strikes on an apartment building in Matsumoto, Japan killed 7, and a subsequent attack on the Tokyo subway system killed a dozen people and caused respiratory effects in thousands.

In the aftermath of the Allied invasion of Iraq in 2003, Kurdish and American tortes reported evidence of attempts to create sarin and VX chemical weapons by the extremist group Ansar al-Islam, allies of Osama bin Laden's al-Qaida terrorist organization. Reports from American forces in Afghanistan suggest similar efforts by terrorists there.

In addition to substances designed specifically to kill or incapacitate human beings, there is a bewildering array of other toxic chemicals that could be employed by terrorists. The Agency for Toxic Substances and Disease Registry (ATSDR) issued toxicological profiles lot 275 priority hazardous compounds. Industrial chemicals are readily and widely available.

Chemical weapons are categorized by the symptoms they induce as nerve agents, blister or mustard agents (also known as vesicants), choking agents and asphyxiants. (See Table 3.) They can be odorless and colorless, or have unique smells. Phosgene, for example, smells like freshly rut grass or corn.

Chemical weapon exposures produce a variety of symptoms, depending on the weapon type and the magnitude of exposure.

Choking agents immediately induce coughing, choking, nausea, headache and a sensation of pressure on the chest. Slowed heart rate is another initial symptom. A symptom-free period then can last for a day, after which symptoms of pulmonary edema set in, including painful cough, respiratory distress and shallow. rapid breathing.

Nerve agents disrupt nerve impulse transmission at the synapses (the points at which nerves meet) and neuromuscular junctions (where nerves and muscles meet). Depending on the severity of exposure, symptoms of nerve agent poisoning can appear within minutes or after many hours, although they generally are immediate. (31) In addition to common symptoms such as salivation, urinary incontinence and diarrhea, other signs and symptoms may include confusion, seizures, coma or hallucinations. Pallor, weak breathing and hypertension also are seen. A lethal paralysis often ensues. Neurological effects vary, depending on the magnitude of exposure. Small doses result in insomnia, nightmares, irritability and difficulty concentrating, for example, whereas large exposures cause unconsciousness, apnea, fatigue, severe memory, impairment or seizures. Nerve agent symptoms are represented by the acronym SLUDGE:

* S: Salivation.

* L: Lacrimation (tearing of the eyes).

* U: Urinary incontinence.

* D: Diarrhea.

* G: Gastrointestinal distress.

* E: Emesis (vomiting).

Blister agents, or vesicants, cause chemical burns and blisters on the skin, eves and mucous membranes. Initial symptoms are aching eyes with uncontrolled tearing, skin and mucous membrane inflammation and irritation, coughing, sneezing, nausea, diarrhea and hoarseness. Blindness can ensue.

Decontamination and Treatment

Decontamination reduces exposure and the risk of secondary contamination. Decontamination involves removing clothing and jewelry, followed by soap and water rinsing. The resulting hazardous waste water should be collected and not allowed to flow off site or be flushed into sewers. Hot water and scrubbing of skin should be avoided.

Vesicants have more severe effects on children than adults, in part because children have thinner skin and are closer to the ground, where mustard vapors collect. (32) Treating pediatric patients should take priority after a chemical attack.

Victims of chemical attacks often require ventilation support for up to 3 hours in severe cases. In nerve agent attacks, atropine is an effective antidote. Depending on the severity of symptoms, 2 to 20 mg of atropine is used. Pralidoxime chloride (2-PAMCI) is another nerve agent antidote, though its effectiveness wanes sharply with time after exposure. Atropine and 2-PAMCI sometimes are delivered simultaneously to patients in an injector kit. Anticonvulsants such as diazepam also may be administered to nerve agent victims.

Despite 75 years of scientific research, no specific antidote has been discovered lot vesicants like mustard gas. Once chemical attack victims are stabilized, supportive care is the norm.

Secondary Contamination

Secondary contamination is the movement of toxic chemicals from victims to other, uncontaminated individuals, including medical personnel. In the aftermath of a chemical weapons attack, secondary contamination can create additional casualties. Patient decontamination is therefore a top priority and should be undertaken as soon as possible. Unless the attack involved only vaporized weapons, all medical personnel who come in contact with victims should wear appropriate personal protective equipment (PPE). Standard protective gear is not adequate; nerve and blister agent liquids pass easily through surgical masks and latex gloves. Hospital personnel involved in patient decontamination should wear Level B PPE (ie, a self-contained respirator and chemical garb) to protect against liquid and vapor exposures. Radiologic technologists should use such equipment as well, if available, even though patients will have been decontaminated by file time they are brought to radiology departments.

Diagnostic Imaging

Diagnostic imaging plays a small role in assessing and treating victims of chemical weapons attacks. However, chest radiographs and high-resolution computed tomography (HRCT) can be used to assess long-term, chronic damage to the lungs in those injured by vesicant weapons. HRCT detects lung abnormalities much more precisely than radiography--20% of patients with abnormal HRCT results have normal chest radiograph findings. Therefore, HRCT should be the imaging technique of choice for assessing pulmonary sequelae in chemical weapons victims. (33) Interstitial lung disease appears to be a long-term outcome of mustard agent exposures. Emphysema and bronchiectasis occur in a quarter of mustard attack victims 15 years after exposure. (33) Laser Doppler imaging (LDI) has been shown to effectively and noninvasively assess tissue perfusion (and, therefore, tissue viability) in vesicant chemical burns. (34)

Radiological Weapons

Thermonuclear war is no longer a likelihood in the United States, but small-scale radiological terrorism is a likely eventuality, either using a crude nuclear device or a radiological dispersal device. Even a small, crude nuclear detonation in a densely populated area would result in significant ionizing radiation exposures and subsequent radioactive fallout, causing lingering illness and death. (32,35) In addition to nuclear bombs or dispersal of radioactive material with explosives, radiological terrorist attacks could include sabotage of radiation therapy clinics or radiopharmaceutical factories, or a major attack on nuclear power plants.

Our current understanding of radiation injury is based largely on studies of past exposures. Hiroshima and Nagasaki, Japan were destroyed by atom bombs in 1945, for example, and the U.S. government conducted nuclear testing in the Marshall Islands in the 1940s and 1950s. More recently, the Chernobyl nuclear power plant in the former Soviet Union suffered a meltdown, and Brazilians in the village of Goiania were exposed to cesium-137 when they opened a canister found amid abandoned radiation therapy equipment at a medical clinic. (36) We now know that the amount, type and duration of radiation exposure have important implications tot medical care. We also have learned about the long-term or chronic effects of radiation exposure. Studies of survivors in Hiroshima, Nagasaki, Chernobyl and the Marshall Islands have shown, for example, that exposed children suffer significant increases in the risk of developing thyroid cancer.

Types of Radiation

Ionizing radiation comes in 2 forms: particulate and electromagnetic. Alpha and beta radiation are particulate types of radiation. Beta particles are found in nuclear fallout and cause radiation burns. Particulate radiation only effects internal organs if it is inhaled. Gamma rays (and x-rays) are electromagnetic radiation; gamma rays are released during nuclear bomb detonation and during subsequent nuclear fallout. Gamma radiation also is emitted by radioisotopes such as cesium. Much more dangerous are neutrons, which are released only in the detonation of nuclear bombs.

Types of Exposure

Three types of radiation injury can occur: external irradiation, contamination mad incorporation. External irradiation involves exposure to penetrating radiation from an x-ray or other external source. External irradiation does not leave individuals radioactive. Contamination with radioactive material involves environmental exposure to radioactive gas, aerosol, liquid or solid material. In most incidents involving contamination, the skin, lungs and internal organs (via the bloodstream) are contaminated. Incorporation occurs after contamination mad refers to the active uptake of radioactive materials by the body's cells and tissues.

Dirty Radiological Bombs

Terrorists actively seek material for both traditional nuclear bombs and radiological "dirty bombs." Dirty bombs are probably a more immediate threat, but they are also a much less serious one. Dirty bombs are radiological dispersal devices that combine a conventional explosive with radioactive materials. The explosion used to disperse radioactivity and the panic following such a weapon's use probably would claim more lives in the short term than radiation effects. This is because the most likely sources of radioactive material, such as therapeutic and diagnostic radioisotopes stolen from hospital radiology departments, probably would not deliver sufficient ionizing radiation to cause acute radiation symptoms. (37)

Patient Handling and Triage

Victims of radiological terrorism, as opposed to chemical or biological terrorism, represent relatively little risk to medical personnel. The basics of handling victims of a radiological attack are: (38)

* Trauma treatment. Address life-threatening conditions without consideration of radiation or contamination status. Serious medical problems always take priority over radiological exposure concerns.

* Decontamination. Health care facilities should plan decontamination procedures mad include them in institutional disaster plans. Noncontaminated patients may be treated in normal treatment areas, but contaminated patients should be taken to special decontamination and treatment areas, preferably outside the hospital.

* Biological dosimetry. After stabilization and decontamination, patients' skin, urine, feces, body orifices and wounds or wound dressings should be swabbed or sampled to determine the extent of contamination. If possible, patients with high levels of exposure should be human leukocyte antigen (HLA) typed before blood cell counts drop, in case bone marrow transplantation becomes necessary.

* Prophylaxis. Potassium iodide (KI) prevents thyroid uptake of radioactive iodine (I 131) and should he administered to victims, especially pregnant women, adolescents and children, because children are more susceptible to developing thyroid cancer than adults. KI should he administered within an hour of exposure.

* Monitoring. Blood cell counts should he conducted every 6 hours for 2 days in cases of whole-body irradiation, such as that which might occur following detonation of a nuclear bomb.

Clinical Presentation

The total amount of body irradiation can be estimated from symptoms and measured by biological (as opposed to environmental) dosimetry, such as the rate of white blood cell population decline over time.

With doses less than 50 mGy (5 rads), there is no detectable injury and no symptoms appear. At 1 Gy (100 rads), nausea mad vomiting occur for 1 to 2 days and production of new blood cells in the marrow temporarily declines. At 3.5 Gy (350 rads), nausea and vomiting are followed by a period of apparent recovery. However, 3 to 4 weeks after exposure, white blood cell and platelet populations may plummet.

Acute radiation syndrome (ARS) is caused by whole-body irradiation. Signs and symptoms are nonspecific and increasingly severe with greater radiation exposure. However, terrorist attacks with penetrating radiation are likely to involve a nuclear detonation; therefore, medical personnel will be aware of the cause of casualties. ARS presents in 4 distinct stages nr phases: pro-drome, latent period, illness and recovery or death. Prodromal patients experience nausea, loss of appetite, fatigue and diarrhea. Extremely high doses of radiation can cause ARS with symptoms such as fever and respiratory distress. After a day or 2, initial ARS symptoms wane, and a symptom-free latent period begins. Illness follows, including infection, electrolyte imbalance, diarrhea, heart failure, bleeding and, in some cases, unconsciousness. If the patient survives this phase, recovery follows.

With increasing radiation exposure, other syndromes may occur in ARS patients, such as:

* Hematopoietic syndrome. At radiation exposure levels exceeding 2 Gy, blood cell counts plummet during a period of hone marrow depression. Infection and hemorrhage risk are extremely high during this period.

* Gastrointestinal syndrome. Patients exposed to 8 to 10 Gy (800 to 1000 rads) or more suffer immediate, profuse vomiting and diarrhea followed by a brief latency period. Gastrointestinal symptoms cause dehydration, and plasma is lost to the intenstine. Septicemia risk is high, and patients who survive long enough art likely to experience hematopoietic syndrome.

* Cardiovascular syndrome. Extremely high doses of radiation (more than 30 Gy) are fatal. Immediate vomiting, irreversible hypotension and unstable blood pressure are followed within a few hours of exposure by fatigue, tremors, convulsions and ataxia. Death follows within a few days.

Treatment

After decontamination and triage, victims exposed to less than 2 Gy (200 rad) should be observed closely and blood cell counts should he taken regularly on an outpatient basis. ARS patients exposed to higher levels of radiation should he evaluated and monitored for secondary syndromes and treated accordingly.

After initial triage and trauma treatment, vomiting can be treated with serotonin blockers and drug therapies such as Prussian Blue. Blood cell production can be stimulated with growth factor therapies such as granulocyte colony stimulating factor or G-CSF. If heavy metal radioisotope exposure leg, plutonium) is suspected, diethylenetriaminepentaacetic acid (DTPA) should be administered intravenously to allow urinary excretion of internal contamination. DTPA is not used after uranium exposure because of kidney damage.

Supportive care, emotional or psychological support and monitoring for lever or infection should follow in a reverse isolation room. Supportive therapy is key to survival. Transfusions, antibiotic therapy and antiviral therapy will prevent life-threatening infections. If bone marrow failure is irreversible despite growth factor therapy, marrow transplantation may be attempted.

Preparedness

Radiologic technologists are on the front lines of prevention and preparedness. Stolen radioisotopes could be used to arm a dirty radiological bomb. Therefore, radiology departments' radioisotope supplies should be closely monitored, all satiety procedures should be scrupulously observed and all department personnel should be alert to the presence of unauthorized people. Technologists should know the signs and symptoms of WMD exposures and the satiety procedures that must be observed in case of a WMD attack.

Surveillance System

Syndromic surveillance tracks the incidence of illnesses with specific signs and symptoms in a population, rather than tracking clinical diagnoses. This approach is well-suited lot detecting bioterrorist attacks because the infectious agents most likely to be used by terrorists do not cause specific or easily differentiated clinical symptoms early in infection. (39) Rather, the early symptoms of smallpox, plague, anthrax and tularemia, including fever, cough and malaise, are indistinct. Because clinicians are likely to misdiagnose these symptoms in early cases, a surveillance system that tracks diagnoses may delay recognition of a bioterrorist attack.

To function efficiently, syndromic surveillance systems must be regionally, nationally and internationally organized, and all participating health care institutions must immediately report all cases with a specified symptom set. (40.41) Real-time monitoring could be achieved by tracking 911 calls, for example. National and regional bioterrorism syndromic surveillance demonstration systems currently are in place or under development. (27.42)

Medical Response

Early recognition of bioterrorist attacks will save lives by allowing early, appropriate medical intervention. Because early symptoms of infection with bioterror agents can overlap and are inconsistent even within one type of infection, lone or first patients from a suspected attack should be subjected to a systematic survey of respiratory rate and distress, color, cardiac activity and skin perfusion, blood pressure, pupil size and reaction and, if possible, be asked about potential exposures to bioterror agents (eg, exposure to visible clouds or explosions).

Unified Command Systems

Managing the response to a terrorist strike is a complex challenge involving cooperation across jurisdictions and between local, state and federal agencies; hospitals; and the media, all of whom may be on the scene simultaneously.

Unified command (UC) systems are flexible and prearranged command structures that direct the flow of information, decisions and resources at the scene of a major catastrophe. UCs coordinate all incident commanders from relevant agencies involved in disaster response. The UC is responsible for overall management of the disaster response, including identifying response goals and coordinating all incident response operations. UC personnel must provide for the safety of emergency medical responders, bystanders and victims.

Beneath the UC is a command staff. The command stall includes public affairs officers who issue press releases, safety officers who identify on-the-scene measures to protect responders and prepare a site safety plan and liaison officers who coordinate the flow of information and communicate decisions to various government officials and investigators arriving at the scene. There is also a general staff of operations officers, planners and logistics staffers who organize the flow of patients and materials to different hospitals.

In May 2000 federal agencies participated in a WMD attack simulation, dubbed TOPOFF (for "top officials"). The multiagency response to the simulated attack followed the UC approach at the incident site. As a result, the U.S. Department of Justice recommended that the nation adopt the UC system as the response management approach to real WMD incidents.

Like onsite incident responders, hospitals should have integrated institutional UC systems in place, with specified duties for each department. Each person should have specific tasks to perform in his or her department, hut all hospital personnel also should be prepared to help wherever they are needed. Unfortunately, although many hospitals have a general disaster response plan, less than 25% have terrorism-specific plans that address the challenges of responding to chemical, biological or radiological terrorism. (6) Once a plan is in place, each department must practice with periodic drills to ensure that the emergency chain of command and individual ditties and department roles are understood by all.

Security

Terrorists may target health care facilities. Confusion and panic are likely to prevail among patients and the public at hospitals in the aftermath of a mass casualty terrorist incident. Victims, family members and frightened lint unharmed citizens will flood hospitals, creating a possible secondary target for terrorists. Security personnel must establish a predetermined perimeter around the hospital, tightly controlling toot and vehicle access.

Strict control of the hospital perimeter is necessary lot another reason. An uncontrolled flow of victims increases the likelihood of cross contamination.. Employee-only entrances should he used to access the hospital, and all noncritical traffic to and from the building should be curtailed.

Patient Decontamination

Avoiding contamination of a health care facility is a major challenge during medical response to a WMD terrorist attack. Secondary contamination can compromise the health and safety of hospital personnel and could even lead to closure of a hospital in the midst of a crisis. Decontaminating victims is, along with the use of appropriate protective garb, a crucial step in protecting medical personnel and the public.

Decontamination should occur immediately after triage in a decontamination zone. If possible this zone should be at an off-site location near the hospital. All contaminated clothing, shoes, contact lenses and jewelry should be removed from patients, bagged in appropriate containers and stored in a secure location for the Federal Bureau of Investigation.

Rapid decontamination is particularly urgent when liquid or vapor weapon agents settle on clothing and skin. Once clothing is removed, soap and cool water should be used to decontaminate victims' skin, and the skin should be flushed thoroughly with water. Patients should not be washed with decontaminating solutions containing bleach or vinegar.

Forensics

Health care personnel will play a unique role in collecting critical evidence lot intelligence and law enforcement investigations into a terrorist attack. Interrogation scripts should be available at hospitals. These scripts will he used to ask each patient about the time and location of an overt attack: unusual events or people observed by the patient; and unusual objects, sounds or smells noticed dining or immediately after the attack.

Telemedicine

Emergency departments near a terrorist WMD attack are likely to be quickly overwhelmed. Properly planned telemedicine consultations can alleviate the backlog of patients and help emergency morn personnel decide which patients should be transported elsewhere for treatment. Coordinating the distribution of data from a mass casualty terrorist attack for off-site analysis is a major logistical challenge that must be carefully planned in advance, however. (43,44) Prior reciprocal burden-sharing agreements most be in place among hospitals and clinics around the nation. Integrated regional telehealth networks should be included in institutional and regional disaster preparedness plans. (44)

Real-time videoconferencing and Internet links will be crucial tools for such consultations. In theory, the Internet should be a particularly attractive mode of communication, because it was initially designed by the Defense Advanced Research Project Administration to survive nuclear missile strikes by rerouting traffic around disabled nodes within the network. In case of an actual nuclear detonation, however, it is likely that local Internet service providers will be lost. Hospitals therefore should have satellite uplink capabilities to connect them to the Internet and allow telemedical consultations.

Conclusion

Radiologic technologists will play important roles if terrorism strikes the United States. The era when these concerns were academic is gone; most experts agree that such an attack is an eventuality, rather than a remote and theoretical possibility. Terrorism prevention and preparation require daily vigilance, and diagnostic imaging may be an important component in identifying the nature and severity of a WMD attack. Knowing the threats, their signs and symptoms and the data physicians will need to treat patients are crucial first steps in preparing for a terrorist strike.
Table 1
Categories of Threat Posed by Biological Agents (14)

Category   Agents

A          Anthrax (Bacillus anthracis)
           Smallpox (Variola Major)
           Botulism (Clostridium botulinum toxin)
           Plague (Yersinia pestis)
           Tularemia (Rancisella tularensis)
           Viral hemorrhagic fevers

B          Q Fever (Coxiella burnetti)
           Brucellosis (Brucella spp.)
           Glanders (Burkholderia mallei)
           Ricin (Ricinus communis toxin)
           Epsilon (Clostridium perfringes toxin)
           Staphylococcus enterotoxin B

C          Hantavirus
           Nipah virus
           Yellow fever
           Tickborne encephalitis viruses
           Multidrug-resistant tuberculosis (TB)


References

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Table 2

Hemorrhagic Fever Viruses

Flaviviridae Yellow fever Dengue

Bunyaviridae Hantavirus

Arenaviridae Lassa Argentine hemorrhagic fever Bolivian hemorrhagic fever Brazilian hemorrhagic fever Venezuelan hemorrhagic fever

Filoviridae Ebola Marburg

Table 3

Types of Chemical Weapons

Blister agents (Vesicants) Phosgene oxime (CX) Sulfur musturd Nitrogen mustards Phenyldichloroarsine Lewisite Levinstein

Nerve agents Sarin VX Tabun Soman

Asphyxiants Hydrogen cyanide Cyanogen chloride

Choking agents Chlorine Chloropicrin Phosgene Diphosgene

Directed Reading Continuing Education Quiz

Biological, Chemical And Radiological Terrorism

To receive Category A continuing education credit for this Directed Reading, read the preceding article and circle the correct response to each statement. Choose the answer that is most correct based on the text. Transfer your responses to the answer sheet on Page 142 and then follow the directions for submitting the answer sheet to the American Society of Radiologic Technologists. You also may take Directed Reading quizzes online at www.asrt.org.

* Your answer sheet for this Directed Reading must be received in the ASRT office on or before this date.

1. Which factors contribute to the current lack of preparation for weapons of mass destruction (WMD) terrorism?

1. medical purchasing systems 2. the shortage of nurses 3. hospital closures

a. 1 and 2 b. 1 and 3 c. 2 and 3 d. 1, 2 and 3

2. Between 1993 and 1996, the number of American hospital beds decreased by --.%.

a. 5 b. 7 c. 9 d. 11

3. Which of the following is not a sign that a WMD terrorist attack may have occurred?

a. sudden arrival of patients with similar symptoms b. lone patient with "out-of-place" symptoms c. arrival of patients with varying symptoms from the same office building d. a change in the Department of Homeland Defense's risk ratings color

4. Based on the Centers for Disease Control (CDC) biological threat categories, which of the following agents poses the least threat for bioterrorism?

a. anthrax b. hantavirus c. smallpox d. plague

5. Victims of the 2001 postal service anthrax attacks presented with variable clinical symptoms.

a. true b. false

6. Which of the following diagnostic imaging techniques most clearly reveals abnormalities associated with inhalational anthrax?

a. radiography b. magnetic resonance (MR) imaging c. positron emission tomography (PET) d. computed tomography (CT)

7. Chest radiographs of patients with pneumonic plague may show nodular opacities and diffuse air-space disease. Very rarely, these conditions result in:

a. mediastinal adenopathy. b. consolidated lobar pneumonia. c. cavitation. d. hilar adenopathy.

8. Lawn mowing accidentally caused a recent outbreak of tularemia.

a. true b. false

9. Untreated. --% of typhoidal tularemia patients die.

a. 15 b. 25 c. 35 d. 45

10. Radiographic findings of bronchopneumonia are most strongly indicative of:

a. anthrax. b. smallpox. c. tularemia. d. botulism.

11. Any patient presenting with severe fever and bleeding or vascular involvement should be tested for:

a. hemorrhagic fever. b. plague. c. chlorine exposure. d. sarin exposure.

12. Onset signs and symptoms of the Ebola and Marburg hemorrhagic fevers include:

a. myalgia. b. photophobia. c. bruising. d. petechiae.

13. Diagnostic imaging does not yield clinically useful information for:

a. Ebola. b. anthrax. c. plague. d. smallpox.

14. Early in the course of American hantavirus pulmonary syndrome, chest radiograph findings include all of the following except:

a. interstitial edema. b. subpleural edema. c. diffuse air-space disease. d. lobar consolidation.

15. The Agency for Toxic Substances and Disease Registries (ATSDR) profiled -- priority hazardous compounds.

a. 75 b. 175 c. 275 d. 375

16. Which category of chemical weapons does sarin belong to?

a. choking b. nerve c. blistering d. asphyxiants

17. Usually, patient decontamination after a suspected chemical WMD terrorist attack should include:

a. vigorous scrubbing. b. soap and water rinsing. c. vinegar wash. d. hot water.

18. Standard protective gear is never adequate when decontaminating patients exposed to:

a. class C biological agents. b. nerve agents. c. a nuclear bomb. d. a dirty bomb.

19. In patients exposed to chemical weapons, long-term pulmonary abnormalities are best detected with:

a. radiography. b. MR. c. PET. d. high-resolution computed tomography (HRCT).

20. Irradiated children are at greater risk than adults for developing cancer of the:

a. thymus. b. testis. c. lungs. d. thyroid.

21. What is the top medical priority for radiological terrorism victims?

a. treating trauma b. decontamination c. sampling d. assessing contamination

22. Potassium iodide should be administered within -- hour(s) of radiological exposure.

a. 1 b. 2 c. 3 d. 4

23. Prodromal symptoms of acute radiation syndrome (ARS) include:

a. nausea. h. bleeding. c. heart failure. d. unconsciousness.

24. Whole-body exposure to less than 2 Gy is associated with -- syndrome.

a. hematopoietic b. gastrointestinal c. cardiovascular d. acute radiation

25. Safety officers belong to which echelon of command?

a. unified command b. general staff c. command staff d. crisis response command

Bryant Furlow, B.A., is a freelance science and medical writer. He lives in northern California.

Reprint requests may be sent to the American Society of Radiologic Technologists, Communications Department, 15000 Central Ave. SE, Albuquerque NM 87123-3917.

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Title Annotation:Directed Reading
Author:Furlow, Bryant
Publication:Radiologic Technology
Date:Nov 1, 2003
Words:11318
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