Preparing for Biological and Chemical Attacks

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chapter 5

While conventional weapons, such as explosives and firearms, remain the most likely means by which terrorists might attempt to harm U.S. civilians, the possibility of an attack involving biological or chemical weapons has increased. Many nations and terrorist groups have explored the use of such weapons on small and large scales, and many countries, including the United States, have chemical and/or biological weapons programs or materials used in these types of weapons.

Biological warfare–related technology, materials, information, and expertise—including information on potential U.S. vulnerabilities—have become more readily available. Genetic engineering is only one of several technologies that might allow countries or groups to develop agents, such as modified viruses, that would be difficult to detect and diagnose or that could defeat current procedures for protection and treatment. Furthermore, all the materials needed to produce such agents are dual-use in nature, meaning they have both military and civilian applications, so they are readily available. Any country with political will and competent scientists can produce agents. The threat from chemical warfare may also grow in coming years. Many states have chemical warfare programs, and these capabilities will likely spread to additional states and terrorist groups. Government officials consider smaller-scale bioterrorist events to be more likely than large-scale ones because they are less difficult to engineer. However, federal public health agencies, such as the Centers for Disease Control and Prevention (CDC), have little choice but to prepare for a variety of attacks.


The U.S. General Accounting Office (GAO) defines biological and chemical terrorism as the threatened or intentional release of viruses, bacteria, poisonous gases, liquids, or other toxic substances for the purpose of influencing the conduct of government, intimidating or coercing a population, or simply intending to cause widespread harm. Any such act that has the potential for, or the intention of, infecting, injuring, or killing hundreds, thousands, or even millions of people is considered terrorism.

In 2001 the GAO identified more than forty federal departments and agencies with some role in combating terrorism, with twenty-nine of those having some role in preparing for, or responding to, the public health and medical consequences of a biological or chemical attack. The cabinet-level departments involved include the U.S. Departments of Agriculture (USDA), Commerce, Defense (DOD), Energy (DOE), Health and Human Services, Justice, Transportation, Treasury, and Veterans'Affairs, along with two independent agencies, the Environmental Protection Agency (EPA) and the Federal Emergency Management Agency (FEMA). Within these larger divisions, departmental agencies take on various roles. The Department of Homeland Security, established in 2002, also plays an important role.

These departments and agencies may work alone or with other agencies in emergency planning for averting or responding to attacks. These units participate in activities that include, but are not limited to: (1) detecting biological agents; (2) developing a national stockpile of drugs with which to treat victims of disasters; and (3) developing vaccines, such as the anthrax vaccine, for the widespread inoculation of U.S. citizens and residents.

Funding for Research

In fiscal year 2001 federal departments and agencies reported total funding for research on biological and chemical terrorism in the amount of $156.8 million. Some of the activities funded include the development of technologies to detect bioterrorist attacks. Funding for bioterrorism research increased dramatically in response to the terrorist attacks of September 11, 2001. In September 2003 Health and Human Services Secretary Tommy G. Thompson announced $350 million in grants over five years to establish eight Regional Centers of Excellence for Biodefense and Emerging Infectious Diseases Research. The eight institutions receiving grants include the Harvard Medical School, Duke University, the University of Chicago, and the University of Texas Medical Branch. According to a statement by the National Institute of Allergy and Infectious Diseases, the research conducted by the Regional Centers will include:

  • Developing new approaches to blocking the action of anthrax, botulinum, and cholera toxins
  • Developing new vaccines against anthrax, plague, tularemia, smallpox, and Ebola
  • Developing new antibiotics and other therapeutic strategies
  • Studying bacterial and viral disease processes
  • Designing new advanced diagnostic approaches for biodefense and for emerging diseases
  • Conducting immunological studies of diseases caused by potential agents of bioterrorism
  • Developing computational and genomic approaches to combating disease agents
  • Creating new immunization strategies and delivery systems

On July 21, 2004, President George W. Bush signed into law the Project BioShield Act. Project BioShield authorizes $5.6 billion over ten years for the government to purchase and stockpile vaccines and drugs to fight anthrax, smallpox, and other diseases that may be used in a bioterror attack. The Department of Health and Human Services will purchase seventy-five million doses of an improved anthrax vaccine for the Strategic National Stockpile. In addition, grants for bioterror research will be expedited under Project BioShield, as will the delivery of newly developed drugs to victims who may require assistance.

Funding for Preparedness

In 1999 a National Pharmaceutical Stockpile—a reserve of antibiotics, chemical antidotes, antitoxins, life-support medications, IV administration, airway maintenance supplies, and medical/surgical items for use in an emergency—was first authorized by Congress. In March 2003 it was renamed the Strategic National Stockpile. Initially run by the Department of Health and Human Services and the Centers for Disease Control and Prevention, it is now managed by the Department of Homeland Security. Funding for the stockpile has increased fivefold since its inception. Among its accomplishments is the purchase and storage of enough smallpox vaccine to protect every American citizen.

Federal departments and agencies spent almost $650 million on bioterrorism- and terrorism-preparedness activities for fiscal years 2000 and 2001: $296 million in 2000 and $347 million in 2001. In January 2002 the U.S. Department of Health and Human Services announced $1 billion in bioterrorism preparedness grants to be given to states and cities to increase their ability to respond to bioterror emergencies. The CDC announced in June 2004 that grants of some $840 million were available to assist public health facilities to prepare for and respond to bioterrorism.

The Centers for Disease Control and Prevention (CDC)

Most investments in national defense increase national security, especially by acting as a deterrent against hostile acts. Similarly, investments in the public health system, most experts believe, will provide the best civil defense against biological and chemical terrorism. In the lead among federal agencies preparing for future homeland biological and chemical terrorism incidents is the CDC, headquartered in Atlanta, Georgia. The CDC's programs to fight terrorism—particularly bioterrorism—inte-grate planning and training to develop public health preparedness and include surveillance (monitoring trends), epidemiology (studying the incidence, distribution, and control of disease), rapid laboratory diagnosis, emergency response, and information systems (computers and telecommunications).

The CDC assists state and local public health departments by:

  • Identifying the biological agents likely to be involved in a terrorist attack
  • Developing case definitions to assist in detecting and managing infection with these agents
  • Establishing a Rapid Response and Advanced Technology laboratory, which can provide fast identification of biological and chemical agents rarely seen in the United States
  • Developing a nationwide integrated information, communications, and training network with the Health Alert Network, the National Electronic Data Surveillance System, and Epidemic Information Exchange. The Health Alert Network (HAN) is, according to the CDC Web site (, meant to "ensure that each community has rapid and timely access to emergent health information; a cadre of highly-trained professional personnel; and evidence-based practices and procedures for effective public health preparedness, response, and service on a 24/7 basis." Considered an improvement on the existing system of tracking diseases, the National Electronic Data Surveillance System (NEDSS) will create a nationwide standard for the collection and analysis of all health related data. According to the CDC, the Epidemic Information Exchange (Epi-X) is "the nation's secure, Internet-based communications network for public health investigation and response. Epi-X provides public health officials throughout the United States with up-to-the-minute information, reports, alerts, and discussions regarding terrorist events, toxic exposures, disease outbreaks, and other public health events."

In other programs, the CDC seeks to enhance the public health system and to expand response capacity, provides training in preparedness and response for public health employees, and continues to support and grow its networked information systems.


Civilians are vulnerable to foodborne or waterborne bioterrorism, as demonstrated by the intentional salmonella contamination of restaurant salad bars in and around The Dalles, Oregon, in September and October 1984. A total of 751 people developed salmonella gastroenteritis from eating or working at those salad bars.

The outbreak occurred in two waves: September 9–September 18 and September 19–October 10. Most cases occurred in ten restaurants. Epidemiological studies of customers at four restaurants and of employees at all ten restaurants indicated that eating from salad bars was the major risk factor for infection. Eight of the ten affected restaurants (80%) operated a salad bar, compared with only three of the twenty-eight nonaffected restaurants (11%) in The Dalles.

The investigation did not identify any water supply, food item, supplier, or distributor common to all affected restaurants, nor were the employees exposed to any single common source. Infected employees may have contributed to the spread of the illness, but they did not initiate the outbreak, nor did food-rotation errors or inadequate refrigeration of the salad bars (although they may have promoted bacteria growth).

A criminal investigation revealed that members of a religious commune, the Rajneeshees, had deliberately contaminated the salad bars with salmonella bacteria as part of a plan to influence a county election in favor of candidates they endorsed. By making residents of The Dalles too ill to go to the polls on election day, the group hoped to seize control of the county government. According to most accounts, commune members planned to contaminate The Dalles's municipal water system just before election day. About a month before the election, they began experimenting with the bacteria by poisoning the refreshments they served to two county commissioners who were visiting the Rajneeshees' compound. Later, commune members sprinkled salmonella on produce in grocery stores. Finally, the Rajneeshees sprinkled salmonella bacteria in and around the salad bars of the town's ten most popular restaurants. Within a few weeks, more than seven hundred people had become ill.


Biological Agents

threat delineation. The first step in preparing for biological or chemical attacks is to detect threats. The CDC has gone to great lengths to identify and prioritize biological and chemical weapons agents. Priorities are based less on the likelihood of an agent's use than on its potential to cause widespread catastrophe. Agents have traditionally been evaluated based on military concerns and troop protection, but civilian populations differ in many ways from military populations, having a wider age range and a wider range of health conditions. In general, civilian populations are more vulnerable, and consequences of an attack would be more severe. This means that military priority lists cannot simply be carried over and applied to civilian threats.

In 1999 Congress began to upgrade public health capabilities to respond to potential biological and chemical attacks, making the CDC the lead agency for overall public health planning. The CDC, in turn, formed a Bioterrorism Preparedness and Response Office to focus on several areas of preparedness, including planning, improved surveillance and epidemiological capabilities, rapid laboratory diagnostics, enhanced communications, and medical therapeutics stockpiling.

To focus the preparedness efforts properly, the first step was to identify and prioritize critical biological and chemical agents. Many biological agents affect human beings, but relatively few, authorities reasoned, have the potential to create public health catastrophes that would severely strain U.S. public health and medical systems, so the CDC sought a new threat-assessment method that could be reviewed, reproduced, and standardized.

On June 3–4, 1999, the CDC convened a meeting of national experts to review the threat potential of various biological and chemical agents to civilian populations. The experts included academic infectious disease experts, national public health experts, CDC personnel, civilian and military intelligence experts, and law enforcement officials. They identified agents they believed had the potential for great public health impact based on subjective assessments in four general categories: overall public health impact (the death or disease rates), dissemination potential (how much the disease could spread), public perception of its impact, and the special preparedness needed for each agent. These criteria were weighted on a scale from zero to three for each agent in order to evaluate the potential threat from each. A factor given the most weight received a three (+++), and the factor given the least weight received a zero (0). Final category assignments—A, B, or C threat status—were based on the ratings the agents received in each of the four areas. (See Table 5.1.)

Category A agents have the greatest potential for causing disruption, disease, and mass casualties, and require the broadest public health preparedness, including improved surveillance, laboratory diagnosis, and medication stockpiling. Examples of Category A agents are those that cause smallpox, anthrax, plague, botulism, and tularaemia.

Category B agents have the potential for large-scale catastrophe but generally would cause fewer cases of severe illness and death than Category A agents. They would have a smaller public health and medical impact, have lower public awareness, and require fewer special preparedness measures. Although these, too, should receive heightened awareness from the medical and emergency communities, along with more surveillance and improved laboratory diagnostic capabilities, these are not needed for Category B agents on the order suggested for Category A agents. In Category B are some agents that the CDC and its experts know have undergone development as weapons but that otherwise do not meet Category A criteria, as well as some agents of concern for food and water safety. Examples of Category B agents include organisms that cause Q fever, brucellosis, and glanders, as well as food- or waterborne agents such as salmonella and E. coli pathogens.

Category C agents do not currently appear to present a high bioterrorism threat but may emerge as future threats as scientific knowledge about them improves. These agents are addressed by the CDC's overall preparedness efforts—efforts intended to improve detection and treatment of unexplained illnesses and emerging infectious diseases. Category C agents include the Nipah virus, hantaviruses, yellow fever, and multidrug-resistant tuberculosis.

The agents were categorized based on the evaluation criteria applied to them, especially in Categories A and B. For example, the public health impact of smallpox (Cate-gory A) ranks higher than that of brucellosis (Category B) because the mortality for those untreated is higher for the former (about 30%) than the latter (about 2%). In addition, smallpox has a higher dissemination potential because it can be transmitted from person to person. It ranks higher for special public health preparedness, as well, because additional vaccine must be made and stockpiled, and improved surveillance, educational, and diagnostic efforts are necessary. Other Category A threats, such as inhalation anthrax and plague, also have higher public impact ratings than brucellosis because of their higher morbidity (illness) and mortality (death) rates. Although mass production of Category B agents Vibrio cholerae (the organism causing cholera) and Shigella spp (the cause of shigellosis) would be easier than that of anthrax spores, these agents produce lower morbidity and


Critical biological agents that pose a risk to national security
source: Ali S. Kahn, Alexandra M. Levitt, and Michael J. Sage, "BOX 3. Critical Biological Agents," in "Biological and Chemical Terrorism: Strategic Plan for Preparedness and Response," Morbidity and Mortality Weekly Report, vol. 49, no. RR-4, April 21, 2000, (accessed September 23, 2004)
Category A
The U.S. public health system and primary health-care providers must be prepared to address varied biological agents, including pathogens that are rarely seen in the United States. High-priority agents include organisms that pose a risk to national security because they
  • can be easily disseminated or transmitted person-to-person;
  • cause high mortality, with potential for major public health impact;
  • might cause public panic and social disruption; and
  • require special action for public health preparedness (Box 2).
Category A agents include
  • variola major (smallpox);
  • Bacillus anthracis (anthrax);
  • Yersinia pestis (plague);
  • Clostridium botulinum toxin (botulism);
  • Francisella tularensis (tularaemia);
  • filoviruses,
    — Ebola hemorrhagic fever,
    — Marburg hemorrhagic fever; and
  • arenaviruses,
    — Lassa (Lassa fever),
    — Junin (Argentine hemorrhagic fever) and related viruses.
Category B
Second highest priority agents include those that
  • are moderately easy to disseminate;
  • cause moderate morbidity and low mortality; and
  • require specific enhancements of CDC's diagnostic capacity and enhanced disease surveillance.
Category B agents include
  • Coxiella burnetti (Q fever);
  • Brucella species (brucellosis);
  • Burkholderia mallei (glanders);
  • alphaviruses,
    — Venezuelan encephalomyelitis,
    — eastern and western equine encephalomyelitis;
  • ricin toxin from Ricinus communis (castor beans);
  • epsilon toxin of Clostridium perfringens; and
  • Staphylococcus enterotoxin B.
    A subset of List B agents includes pathogens that are food- or waterborne.
    These pathogens include but are not limited to
  • Salmonella species,
  • Shigella dysenteriae,
  • Escherichia coli O157:H7,
  • Vibrio cholerae, and
  • Cryptosporidium parvum.
Category C
Third highest priority agents include emerging pathogens that could be engineered for mass dissemination in the future because of
  • availability;
  • ease of production and dissemination; and
  • potential for high morbidity and mortality and major health impact.
Category C agents include
  • Nipah virus,
  • hantaviruses,
  • tickborne hemorrhagic fever viruses,
  • tickborne encephalitis viruses,
  • yellow fever, and
  • multidrug-resistant tuberculosis.
Preparedness for List C agents requires ongoing research to improve disease detection, diagnosis, treatment, and prevention. Knowing in advance which newly emergent pathogens might be employed by terrorists is not possible; therefore, linking bioterrorism preparedness efforts with ongoing disease surveillance and outbreak response activities as defined in CDC's emerging infectious disease strategy is imperative.

mortality, so their public health impact, or dissemination threat, would be less. Although infectious doses of these bacteria are very low, it would be very difficult for a terrorist to use them effectively. The total amount of bacteria required, as well as the advanced state of current water purification and food-processing techniques, would limit these agents' effectiveness for intentional, large-scale water or food contamination.

preparedness activities. In addition to identifying major biological agents and threats, the CDC (in its publication Morbidity and Mortality Weekly, vol. 49, no. RR-4, April 21, 2000) provided nine basic steps to prepare public health agencies for biological attacks:

  1. Enhance epidemiologic capacity to detect and respond to biological attacks
  2. Supply diagnostic reagents to state and local public health agencies
  3. Establish communication programs to ensure delivery of accurate information
  4. Enhance bioterrorism-related education and training for health-care professionals
  5. Prepare educational materials that will inform and reassure the public during and after a biological attack
  6. Stockpile appropriate vaccines and drugs
  7. Establish molecular surveillance for microbial strains, including unusual or drug-resistant strains
  8. Support the development of diagnostic tests
  9. Encourage research on antiviral drugs and vaccines

Enhancing epidemiologic capacity means adding additional resources to trace the source and spread of dis-ease. Supplying diagnostic reagents means providing chemical compounds to state and local public health agencies for a variety of medical purposes ranging from detection to prevention.

Chemical Agents

threat delineation. Chemical agents can range from warfare agents to toxic substances in common commercial use. The fact that chemical warfare technologies are increasingly available, coupled with the relative ease with which chemical agents can be produced, increases the U.S. government's concern that terrorist states or groups may use them in the future.

The CDC takes a similar approach to combating chemical threats as it does to biological ones, providing many of the same resources to state and local public health agencies and emergency services teams. However, the CDC's identification and prioritization of critical chemical agents differs from that of biological agents. Because hundreds of new chemicals are introduced inter-nationally each month, the categories of chemical agents are necessarily more generic than for biological agents.

The CDC identifies and prioritizes chemical agents according to criteria including the following:

  • Are the agents already known to be used as weapons?
  • Are they readily available to hostile states and terrorists?
  • Are they likely to cause morbidity or mortality?
  • Are they likely to cause panic or disruption?
  • Do they require special actions for public health preparedness?

Table 5.2 lists the CDC's chemical agent categories, along with notable examples of each. The chemical agents most likely to be used are nerve agents (tabun, sarin, soman, GF, and VX), blood agents (hydrogen cyanide and cyanogen chloride), blister agents (lewisite, mustards, and phosgene oxime), and heavy metals (arsenic, lead, and mercury).

preparedness activities. The CDC provides recommendations to help public health agencies prepare for potential chemical attacks. First, agencies should take a generic approach to the treatment of chemical agent injuries, treating those exposed according to clinical syndrome, or the group of symptoms they have, rather than the specific agent. These syndromes include burns and trauma, cardio-respiratory failure, neurological damage, and shock. Those who respond and treat affected individuals must also communicate with the authorities responsible for environmental sampling for, and decontamination of areas affected by, such chemical agents.

The CDC's five steps in preparing public health agencies for chemical attacks are listed in their publication Morbidity and Mortality Weekly (vol. 49, no. RR-4, April 21, 2000):

  • Enhance epidemiologic capacity for detecting and responding to chemical attacks
  • Enhance awareness of chemical terrorism among emergency medical service personnel, police officers, firefighters, physicians, and nurses
  • Stockpile chemical antidotes
  • Develop and provide bioassays for detection and diagnosis of chemical injuries
  • Prepare educational materials to inform the public during and after a chemical attack

Enhancing epidemiological capacity refers to mapping the origin and spread of disease symptoms. Bioassays are intended to determine the relative strength of a chemical agent by comparing its effect on a test organism with that of a standard-strength preparation.

Laboratory Response Network

The CDC has described five key focus areas of state and local efforts to prepare for biological and chemical attacks:


Chemical agents that might be used by terrorists
source: Ali S. Kahn, Alexandra M. Levitt, and Michael J. Sage, "BOX 5. Chemical Agents," in "Biological and Chemical Terrorism: Strategic Plan for Preparedness and Response," in Morbidity and Mortality Weekly Report, vol. 49, no. RR-4, April 21, 2000, (accessed September 23, 2004)
Chemical agents that might be used by terrorists range from warfare agents to toxic chemicals commonly used in industry. Criteria for determining priority chemical agents include
  • chemical agents already known to be used as weaponry;
  • availability of chemical agents to potential terrorists;
  • chemical agents likely to cause major morbidity or mortality;
  • potential of agents for causing public panic and social disruption; and
  • agents that require special action for public health preparedness (Box 4).
Categories of chemical agents include
  • nerve agents,
    — tabun (ethyl N, N-dimethylphosphoramidocyanidate),
    — sarin (isopropyl methylphosphanofluoridate),
    — soman (pinacolyl methyl phosphonofluoridate),
    — GF (cyclohexylmethylphosphonofluoridate),
    — VX (o-ethyl-[S]-[2-diisopropylaminoethyl]-methylphosphonothiolate);
  • blood agents,
    — hydrogen cyanide,
    — cyanogen chloride;
  • blister agents,
    — lewisite (an aliphatic arsenic compound, 2-chlorovinyldichloroarsine),
    — nitrogen and sulfur mustards,
    — phosgene oxime;
  • heavy metals,
    — arsenic,
    — lead,
    — mercury;
  • Volatile toxins,
    — benzene,
    — chloroform,
    — trihalomethanes;
  • pulmonary agents,
    — phosgene,
    — chlorine,
    — vinyl chloride;
  • incapacitating agents,
    — BZ (3-quinuclidinyl benzilate);
  • pesticides, persistent and nonpersistent;
  • dioxins, furans, and polychlorinated biphenyls (PCBs);
  • explosive nitro compounds and oxidizers,
    — ammonium nitrate combined with fuel oil;
  • flammable industrial gases and liquids,
    — gasoline,
    — propane;
  • poison industrial gases, liquids, and solids,
    — cyanides,
    — nitriles; and
  • corrosive industrial acids and bases,
    nitric acid,
    sulfuric acid.
  1. Preparedness and prevention
  2. Detection and surveillance
  3. Diagnosis and characterization of biological and chemical agents
  4. Response
  5. Communication

Perhaps the most technically challenging of the five focus areas is the third: diagnosis and characterization of biological and chemical agents. For that reason, the CDC and its partners created two multilevel laboratory response networks, one for biological terrorism and one for chemical terrorism. These networks link state-of-theart clinical labs to state and local public health agencies in all states, districts, territories, and selected cities and counties. Each network is a three-level hierarchy of laboratories, according to their respective capabilities. The Laboratory Network for Biological Terrorism consists of three types of laboratories:

  1. National Laboratories are responsible for specialized strain characterizations, bioforensics, select agent activity, and handling highly infectious biological agents.
  2. Reference Laboratories are responsible for investigation and/or referral of specimens.
  3. Sentinel Laboratories play a key role in the early detection of biological agents.

National Laboratories are those run by the CDC or by the U.S. Army Medical Research Institute of Infectious Diseases. There are over a hundred Reference Laboratories across the United States and in Australia and Canada, and some 25,000 designated Sentinel Laboratories.

The Laboratory Network for Chemical Terrorism consists of three levels as well, designated as Levels 1, 2, and 3. All sixty-two laboratories in the network perform Level 1 duties, which are:

  • Working with hospitals in their jurisdiction
  • Knowing how to properly collect and ship clinical specimens
  • Ensuring that specimens, which can be used as evidence in a criminal investigation, are handled properly and chain-of-custody procedures are followed
  • Being familiar with chemical agents and their health effects
  • Training on anticipated clinical sample flow and shipping regulations
  • Working to develop a coordinated response plan for their respective state and jurisdiction

Of the sixty-two chemical terrorism network laboratories, forty-one also participate in Level 2 activities in which laboratory personnel are trained to detect exposure to a limited number of toxic chemical agents in human blood or urine. In Level 3 laboratories, which comprise five of the total sixty-two, personnel are trained to detect exposure to an expanded number of chemicals in human blood or urine, plus analyses for mustard agents, nerve agents, and other toxic chemicals.


In June 2004 the CDC announced the Cities Readiness Initiative pilot program. In this eight-month program the federal government provided direct assistance to cities to help


Why agriterrorism may be an attractive tool for terrorists
source: "Why Agriterrorism May Be an Attractive Tool for Terrorists," in "Appendix E: Agriterrorism," Tool Kit for Managing the Emergency Consequences of Terrorist Incidents, Federal Emergency Management Agency, July 2002, (accessed September 23, 2004)
Lower physical riskDisseminating a plant or livestock disease pathogen presents less physical risk to the perpetrator than releasing human disease pathogens or lethal chemicals.
Smaller chance of outrage and backlashAgriterrorism is not likely to create the same kind of backlash as using a method of terrorism that kills people.
Similarity to natural outbreaksLivestock and crops can be attacked in a way that the disease outbreak mimics a natural disease occurrence, complicating epidemiological investigation and reducing risk of detection.
Lower technical barriersAgriterrorism can be carried out fairly easily, by comparatively low-tech means. The cost and the technical/scientific skills and education required to collect, produce, and deliver biological agents against animal agriculture are modest. Pathogens could be isolated from infected animals or diseased crops, and small quantities could easily be carried across a Customs checkpoint or unregulated border area, or sent through the mail. Then, infection with some pathogens would be simple. (For example, a terrible epidemic could be caused by dropping Newcastle disease-contaminated bird droppings into a feeding trough, or placing tongue scrapings from foot-and-mouth disease-infected animals into the ventilation system of a large hog operation.)

them successfully receive and dispense medicine and medical supplies from the Strategic National Stockpile. Local, state, and national plans to distribute emergency medicines were combined to create a consistent nationwide approach that will ensure deliveries of needed supplies during such emergencies as a bioterrorist attack, a nuclear accident, or an outbreak of disease. Twenty cities and the District of Columbia participated in the $25 million pilot program.


The Animal and Plant Health Inspection Service (APHIS)

Animals and plants, especially those that human beings depend on for food, are also subject to attack. On the front line of this problem is the Department of Homeland Security's Animal and Plant Health Inspection Service (APHIS). APHIS is a largely unknown agency but an important one. It monitors the nation's borders for foreign agricultural diseases and pests. It protects farm animals from disease and pests and provides a host of services to cattle ranchers, milk producers, turkey farmers, and other agrarian groups.

According to the Center for Nonproliferation Studies report Chronology of CBW Attacks Targeting Crops and Livestock, 1915–2000 (October 2001), bioterror attacks on a nation's animals and agriculture are not uncommon in times of war. The German secret service deployed anthrax against horses and mules slated for use by the Allied powers in World War I. In Afghanistan in the 1980s, the Russian military used toxins against the horses of the rebel mujaheddin. England suspected that Nazi Germany had dropped Colorado potato beetles on rural areas during World War II to destroy potato crops; in 1950, communist East Germany accused the United States of a similar attack.

One in eight American jobs and 13% of the U.S. gross national product (the value of all the goods and services produced in the country) are dependent on agriculture. The country's economic stability depends on a safe and readily available food supply. U.S. crops and livestock could be tempting targets to terrorists, especially because of the perceived ease of attacking such targets. (See Table 5.3.) Livestock and plant pathogens could threaten U.S. agricultural productivity and cause economic damage. Such factors as the resilience of the agent used, the density of the targeted animal population, and the susceptibility of targeted plants and animals to disease determine the level of vulnerability. (See Table 5.4.)

Potential threats to U.S. agricultural products and livestock come from a number of pathogens and agents. Animals could contract many types of disease, including anthrax, Q fever, brucellosis, foot-and-mouth disease (FMD), Venezuelan equine encephalitis, hog cholera, African swine fever, avian influenza, Newcastle disease, Rift Valley fever, rinderpest, and others. The Office International des Epizooties (OIE) is a 155-member organization that sets the animal health standards for international trade. They maintain two lists of diseases: List A includes diseases with the potential for very rapid spread across national borders and serious socio-economic or public health consequences. List B includes diseases that are considered dangerous within the individual country where an outbreak occurs. Table 5.5 shows the List A and many of the List B animal diseases. Many staple plants, such as corn, wheat, rice, and soybeans, are susceptible to disease. Soybean rust, for example, can be easily introduced and spreads quickly, which could cause U.S. soybean producers, processors, livestock producers (who feed soy products to their animals), and consumers to lose up to $8 billion annually, according to USDA estimates. Table 5.6 lists plant diseases of particular agriterrorism concern.

Some of these plant and animal agents can be found outside U.S. borders, and many can be readily transported, inadvertently or intentionally, into the United States, some with low risk of detection. APHIS is the agency


Factors that affect vulnerability to agriterrorism
source: "Factors That Affect Vulnerability," in "Appendix E: Agriterrorism, " Tool Kit for Managing the Emergency Consequences of Terrorist Incidents, Federal Emergency Management Agency, July 2002, (accessed September 23, 2004)
Number of agentsThere are many agents (at least 22) that are lethal and highly contagious to animals, many of which are not vaccinated against.
ResilienceMost of these agents are environmentally resilient. They can live for a long time in organic matter (e.g., soil).
SusceptibilityAntibiotic and steroid programs, and husbandry programs designed to improve quality and quantity of meat, have made U.S. livestock more disease prone. U.S. livestock and poultry are especially susceptible to exotic diseases because most serious diseases that affect them have been eradicated or brought under control with U.S. borders, so the animals lack antibodies to fight these agents. In crops, widespread use of commercial hybrids has limited their genetic diversity, making them more vulnerable to a killer pathogen.
Concentrated populationsAnimal populations are highly concentrated, and large herds make ideal targets for infection and contagion. For example:
  • About 75% of the swine industries concentrated in nine Midwestern States; the most successful swine farms each have 10,000 hogs or more.
  • Beef cattle are fattened in large feedlots—some containing 150,000 to 300,000 animals at a time.
  • Dairies usually have as many as 1,500 lactating cows at one time.
  • Poultry has a heavy concentration in the Delaware/Maryland/Virginia peninsula. Chickens are usually grown in floor pens with 10,000 to 20,000 birds per pen.
MobilityAnimal populations are highly mobile. The animals are typically born in one location, moved halfway across the country to a feedlot for final fattening, then moved again for slaughter. Chicken breeding stocks and eggs are shipped great distances for the purpose of genetic improvements. Animals that are incubating disease during these movements can greatly increase the spread of the disease.
Inadequate securityAgricultural facilities are not highly secure. Food processors lacking sufficient security and safety preparedness methods have proliferated over the years.
Limited detection capabilitiesThe United States is even more vulnerable because it is unprepared to prevent such an attack or even quickly detect an outbreak. (Veterinary students receive minimal education in foreign animal diseases). Our primary recourse would be response, after an attack has occurred.


Transmissible animal diseases identified as threats by the International Office of Epizootics, 2002
List A diseases1Selected List B diseases2
1List A: Transmissible diseases which have the potential for very serious and rapid spread, irrespective of national borders, which are of serious socio-economic or public health consequence and which are of major importance in the international trade of animals and animal products.
2List B: Transmissible diseases that are considered to be of socioeconomic and/or public health importance within countries and which are significant in the international trade of animals and animal products. Other categories of List B diseases include equine, sheep, goat, fish, crustacean, bee, Lagomorph, mollusc, and other.
source: "Animal Diseases: List A Diseases and Selected List B Diseases," in "Appendix E. Agriterrorism," Tool Kit for Managing the Emergency Consequences of Terrorist Incidents, Federal Emergency Management Agency, July 2002, (accessed September 23, 2004)
  • African horse sickness
  • African swine fever
  • Bluetongue
  • Classical swine fever
  • Contagious bovine pleuropneumonia
  • Foot-and-mouth disease
  • Highly pathogenic avian influenza
  • Lumpy skin disease
  • Newcastle disease
  • Peste des petits ruminants
  • Rift Valley fever
  • Rinderpest
  • Sheep pox and goat pox
  • Swine vesicular disease
  • Vesicular stomatitis
Multiple species:
  • Anthrax
  • Aujeszky's disease
  • Echinococcosis/hydatidosis
  • Heartwater
  • Leptospirosis
  • New World screwworm Cochliomyia hominivorax)
  • Old World screwworm (Chrysomya bezziana)
  • Paratuberculosis
  • Q fever
  • Rabies
  • Avian infectious bronchitis
  • Avian infectious laryngotracheitis
  • Avian mycoplasmosis (M. avian chlamydiosis gallisepticum)
  • Avian tuberculosis
  • Duck virus hepatitis
  • Duck virus enteritis
  • Fowl cholera
  • Fowl pox
  • Fowl typhoid
  • Infectious bursal disease (Gumboro disease)
  • Marek's disease
  • Pullorum disease
  • Bovine anaplasmosis
  • Bovine babesiosis
  • Bovine brucellosis
  • Bovine cysticercosis
  • Bovine genital campylobacteriosis
  • Bovine spongiform encephalopathy (BSE)
  • Bovine tuberculosis
  • Dermatophilosis
  • Enzootic bovine leukosis
  • Haemorrhagic septicaemia
  • Infectious bovine rhinotracheitis/infectious pustular vulvovaginitis
  • Malignant catarrhal fever
  • Theileriosis
  • Trichomonosis
  • Trypanosomosis (tsetse-borne)
  • Atrophic rhinitis of swine enterovirus encephalomyelitis
  • Porcine brucellosis
  • Porcine cysticercosis
  • Porcine reproductive and respiratory syndrome
  • Transmissible gastroenteritis
  • Trichinellosis


Crop diseases of particular agriterrorism concern
Crop affectedDiseasePathogenPathogen typePrimary mode of transmission
source: "Crop Diseases of Particular Agriterrorism Concern," in "Appendix E. Agriterrorism," Tool Kit for Managing the Emergency Consequences of Terrorist Incidents, Federal Emergency Management Agency, July 2002, (accessed September 23, 2004)
Cereals (wheat, barley, rye)Stem rust of wheatPuccinia graminisFungusAirborne spores
Stem rust of cerealsPuccinia glumarumFungusAirborne spores
Powdery mildew of cerealsErysiphe graminisFungusAirborne spores
CornCorn blightPseudomonas alboprecipitansBacteriaWaterborne cells
RiceRice blastPyricularia oryzaeFungusAirborne spores
Rice blightXanthomonas oryzaeBacteriaWaterborne cells
Rice brown-spot diseaseHelminthosporium oryzaeFungusAirborne spores
PotatoLate blight of potatoPhytophthora infestansFungusAirborne spores

responsible for diagnosing and managing all suspicious agricultural disease outbreaks. APHIS's authority, depending on the pathogen involved, extends as far as confiscating property and eradicating all plant and animal hosts within quarantine zones. Binding international agreements force countries to immediately disclose select plant and animal disease outbreaks, regardless of severity. Such disclosures can have an instant impact on export trade, as other countries prohibit potentially contaminated items from entering their borders. National security and public trust can both be threatened in such cases, depending on the extent of disease transmission, the success of the government's response, and the amount of time it takes to bring conditions back to normal.

Foot-and-Mouth Disease (FMD)

One example of how countries' livestock industries can be affected by disease has been the various outbreaks of foot-and-mouth (also called hoof-and-mouth) disease. During an outbreak in the United Kingdom in 1967 and 1968, for example, more than 430,000 animals were destroyed; an outbreak in 2000–01 in the United Kingdom and Ireland forced the destruction of more than eight million animals at over ten thousand locations. The out-break caused severe economic hardship throughout the United Kingdom and parts of Europe.

A member of the picornavirus family, FMD is endemic in many parts of the world, but the United States has not seen cases since the 1920s. Thus, few American veterinarians are familiar with the early stages of FMD infection. An animal becomes infected shortly after exposure but well before the onset of clinical symptoms. When symptoms do occur, they may include a sudden rise in temperature, followed by an eruption of blisters in the mouth, in the nostrils, on areas of tender skin, and on the feet. The blisters expand, then break, exposing raw, eroded skin surfaces. Eating becomes difficult and painful. Because the soft tissue under the hooves is swollen, the animal limps. Livestock raised for meat lose weight, and dairy cattle and goats give far less milk. FMD kills very young animals and causes pregnant females to abort.

Merely transporting infected tissue can start an epidemic—a single infected cow or pig can generate enough viral particles to communicate the disease over vast geographic areas in weeks. An outbreak of this disease could be easily introduced to the United States and might debilitate the U.S. livestock industry. According to the USDA, an outbreak could cost as much as $20 billion over fifteen years in increased consumer costs, reduced livestock productivity, and restricted trade.

APHIS does not permit imports of FMD-positive animals. While scientists appear close to developing an effective vaccine, vaccinating all susceptible animals would cost about $1 billion annually. In addition, the vaccine would not eradicate the disease. Currently the only effective countermeasure against FMD is slaughtering and incinerating all exposed and infected animals.