Chemical & Biological Weapons Resource Page

October 3, 2001, 10:30 a.m.
Room 216, Hart Senate Office Building
Washington, D.C.

Mr. Chairman, distinguished Members of the Subcommittee, and guests:

Many thanks for the opportunity to testify before you today on a concern that has gripped the nation in the wake of the September 11 terrorist attacks on the World Trade Center and the Pentagon: the possibility that terrorists might escalate their horrific campaign of death and destruction by resorting to the use of unconventional weapons, including biological pathogens. Although experts disagree over the ease with which terrorists could acquire and use biological weapons, many studies have concluded that the threat of bioterrorism against the United States is growing, and that the nation is not adequately prepared to handle even a medium-sized biological attack. With a potential health emergency in the making, time is of the essence in reducing our vulnerability to this threat, and I believe there is much we can do in the near-term.

It is important to note that bioterrorism and the growing challenge of natural emerging infectious diseases are two sides of the same coin. Both phenomena would manifest themselves in the form of an unusual outbreak of infectious disease -- one that would have to be rapidly detected, identified, and contained to minimize the harmful consequences. Because some of the most deadly biological warfare agents, such as anthrax and plague, respond to antibiotics administered during the early phase of infection, prompt detection and treatment of an outbreak could save many lives. With a contagious agent, rapid containment by isolation and vaccination could prevent further spread.

The threats of emerging infections and bioterrorism can both be addressed most effectively by strengthening the nation's public health systems, which have been allowed to atrophy over the past several decades.[1] Back in the 1950s and ‘60s, publicly supported community hospitals and public health laboratories supported an effective early-warning network for detecting and containing epidemics. Since then, however, the shift to privatized medicine and managed care has largely eliminated this system. Shortages of manpower and infrastructure in the nation's public health departments have also impeded effective epidemiological surveillance, leaving the public more vulnerable to serious outbreaks of infectious disease.[2]

My testimony will briefly address the dual threats of bioterrorism and emerging infectious diseases, point out some key gaps and weaknesses in our current public health defenses, and conclude with a number of practical policy recommendations for improving U.S. response capabilities.

The Threat of Bioterrorism

Although it is unlikely that a small terrorist group working on its own would have the technical and financial resources to carry out a major bioterrorist attack on the scale of the September 11 event, a state-sponsor might provide the terrorists with the necessary know-how, seed cultures, and specialized dissemination equipment. Alternatively, a wealthy terrorist organization might be able to recruit scientists and engineers formerly employed by a state-level biowarfare program, such as that of Iraq, South Africa, or the former Soviet Union. As the biotechnology industry continues to spread rapidly around the world, fermentation tanks and other equipment used to produce biological warfare agents -- much of which has commercial as well as military applications -- will become increasingly accessible to terrorists. Moreover, given the current high level of public anxiety over bioterrorism, even a relatively small-scale attack with anthrax or some other biological agent could have a disproportionate psychological impact, eliciting widespread panic and undermining trust in government.

Defense analysts also worry about the possible use of biological agents by hostile states as a means of "asymmetric warfare" -- David-and-Goliath strategies in which small countries would seek to circumvent or blunt the conventional military supremacy of the United States and its ability to intervene in regional conflicts. Such strategies might involve the use of disease agents to attack troops or civilians, destroy U.S. crops or livestock, or contaminate the nation's food supply. Biological attacks could be carried out on a scale large enough to hamper or deter U.S. intervention abroad, yet without crossing the mass-casualty threshold that could credibly trigger nuclear retaliation. Even in the face of U.S. deterrent threats, a rogue state or terrorist group that believed it could carry out an attack without attribution might be tempted to do so, particularly in the heat of crisis or war.

A bioterrorist attack would probably involve the covert release of a microbial pathogen that would give rise to detectable illness only after an asymptomatic delay, or incubation period, when the microorganism is multiplying in the host to cause disease. For example, Bacillus anthracis, the bacterium that causes anthrax, has an incubation period of roughly six days. Individuals who had been exposed to an invisible aerosol cloud of anthrax spores would probably be unaware at the time that they had been infected. The first evidence of the attack would emerge days later, when the infected individuals, by now widely dispersed, began to develop nonspecific, flu-like symptoms such as fever, fatigue, cough, and chest discomfort. A few days later, severe symptoms would set in, including difficulty breathing, sweating, anoxia (causing the victim to turn blue), and death, if the disease remained untreated. Anthrax is not—I repeat, not—transmissible from person to person, but because the disease is generally fatal within 24 to 36 hours after the onset of severe symptoms, antibiotic therapy (possibly combined with post-exposure vaccination to enhance the patient's immune response) must begin as soon as possible to have any chance of success. It is therefore essential to identify an outbreak linked to a bioterrorist attack early, while the disease is still treatable.

An even more challenging scenario would involve the deliberate release of a contagious agent, such as plague bacteria or smallpox virus. Plague has an incubation period of one to six days, whereas smallpox has an incubation period of roughly 12 to 14 days. By the time the first cases of smallpox were diagnosed, the initial group of cases would probably have infected close contacts, such as family and friends. In this case, it would be essential to launch an aggressive vaccination campaign to contain the epidemic before the infection spread through the general population in a series of expanding waves.

The Threat of Natural Emerging Infections

In parallel to the emerging threat of bioterrorism, the United States faces a growing problem of infectious disease from natural sources. During the 1960s and ‘70s, powerful antibiotic drugs and vaccines appeared to have banished the major infectious scourges from the industrialized world, leading to a sense of complacency and neglect of programs for disease surveillance and prevention. Over the past two decades, however, several well-known diseases, such as tuberculosis, malaria, and cholera, have re-emerged in more virulent or drug-resistant forms or have spread geographically. At the same time, scientists have identified a host of previously unknown infections, including Legionnaire's disease, AIDS, Lyme disease, Sin Nombre virus, hepatitis C, "mad cow disease," Nipah virus, and new strains of influenza. AIDS was not recognized until the 1980s, yet it now infects some 36 million people worldwide and kills 3 million annually. Since 1980, the U.S. death rate from AIDS and other infectious diseases has increased by about 4.8 percent per year, compared with an annual decrease of 2.3 percent for the 15 years before 1980.[3]

Several factors have contributed to the problem of emerging infections:

• The inappropriate use of antibiotic drugs has fostered the evolution of resistant strains of tuberculosis and other bacterial diseases, even as the development of new generations of antibiotics has lagged.
• Ecosystem disturbances, such as clearing rainforests for economic gain or human settlements, have altered the geographical distribution of disease vectors such as rodents, monkeys, and mosquitoes, increasing their contact with humans.
• Rapid population growth and rural-urban migration have given rise to "megacities" in the developing world with poor public health infrastructure, enabling diseases that once remained isolated in rural areas to spread to large urban populations.
• The collapse of public health systems in Russia and other parts of the former Communist world have fostered the spread of diseases such as AIDS and drug-resistant tuberculosis.
• The rising volume of tourism, trade, and imported agricultural goods associated with economic globalization has created new opportunities for the introduction into the United States of disease vectors and microbial pathogens from other parts of the world.

Because most U.S. cities are within a 36-hour commercial flight of any part of the globe, or less than the incubation period of many infectious diseases, infected individuals may not be visibly ill when they cross a U.S. border. The risk of disease importations is greatest in major hubs of global commerce such as New York City, Los Angeles, and Miami. Indeed, the source of the 1999 outbreak in New York of West Nile encephalitis, a viral disease never before seen in the Western Hemisphere, may have been travelers from the Middle East who were incubating the disease or a stray infected mosquito on an airplane. Having spread widely over the past three years, West Nile virus is now permanently entrenched in the United States.

A future emerging infection introduced into our country could be far more deadly. In the worst-case scenario, a new pathogen would have the attributes of the 1918 strain of influenza virus, or Spanish Flu, which was highly transmissible through the air and uncharacteristically lethal to young, healthy people. This disease caused a global pandemic that claimed more than 20 million lives in less than two years. The speed at which the U.S. public health system could identify and contain such an outbreak would mean the difference between life and death for a large number of Americans.

Current Deficiencies in Infectious Disease Surveillance

In the event of a major outbreak of disease -- whether the result of a natural emerging infection or a deliberate terrorist attack -- city, county, and state health departments would be the nation's first line of defense, backed up by the medical detectives and virus hunters at the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and other federal agencies. The first indication of an unusual disease outbreak would be when the initial victims became ill and sought treatment at emergency rooms and doctors' offices. For example, a group of people living in an urban neighborhood or working in an office building that had been subjected to a covert bioterrorist attack might initially develop nonspecific, flu-like symptoms. Detection and containment of a disease outbreak would entail four basic steps:

1. Recognition and diagnosis by primary health care practitioners. Medical clinicians would identify cases of an unusual infectious disease or an undiagnosed "syndrome" (cluster of symptoms). Clinical laboratories would then attempt to identify the causative agent from patient blood, urine, or other specimens.
2. Communication of surveillance information to public health authorities. Physicians and infectious-disease specialists who had detected an unusual pattern of disease incidence, such as several patients with the same symptoms, would report their observations to local or state public health authorities.
3. Epidemiological analysis of the raw surveillance data. Epidemiologists working for the health department would interpret the disease-surveillance data to determine the source of the outbreak, the mode of transmission, and the extent of exposure. They would then make recommendations for appropriate treatment and public health measures (e.g., vaccination) to contain the outbreak.[4]
4. Delivery of the appropriate medical treatment and public health measures. Patients seriously affected by the disease would be admitted to hospitals for treatment. Those infected with a contagious agent would be isolated and all potential contacts vaccinated (if vaccine is available) to prevent the disease from spreading.

Today, a major epidemic arising either from a natural emerging infection or an act of bioterrorism would pose serious challenges to the U.S. public health system in all four areas identified above. Useful lessons can be drawn from the 1999 epidemic of West Nile encephalitis in New York City, which revealed some serious gaps in the existing system of disease surveillance and response. These gaps must be remedied if the nation is to be better prepared in the future.

The first manifestation of the West Nile epidemic appeared in early July 1999, when common birds such as sparrows, robins, and crows began to die in unusual numbers in northern Queens and the South Bronx. One month later, humans in the same area began to be stricken with encephalitis, or inflammation of the brain, although a possible connection with the bird die-off was not suspected at the time. The human outbreak was detected when a physician at a hospital in Queens admitted several elderly patients with an atypical form of encephalitis that was accompanied by severe muscle weakness. Unable to diagnose this condition, she took the initiative of reporting the unusual cases to the New York City Department of Health. Recognizing the possibility of an infectious disease outbreak, health department officials then called doctors at 70 hospitals around the city and identified 30 similar cases of encephalitis.[5]

In early September 1999, the Centers for Disease Control's laboratory for vector-borne infectious diseases in Fort Collins, Colo., analyzed patient specimens from the New York outbreak and identified the causative agent as St. Louis encephalitis virus. Three weeks later, however, the CDC was forced to admit that its initial diagnosis had been incorrect and that the infectious agent was actually West Nile virus, a disease endemic to East Africa and the Middle East that had never before been reported in the Western Hemisphere. The three-week delay in reaching the correct diagnosis revealed some significant deficiencies in the U.S. public health system:

• CDC scientists investigating the outbreak suffered from "tunnel vision" by screening only for encephalitis viruses commonly found in the United States and neglecting those linked to foreign outbreaks or possibly developed for bioterrorism.
• CDC scientists repeatedly rebuffed a veterinary pathologist at the Bronx Zoo who suspected a possible link between the bird and human outbreaks. Community newspapers in northern Queens had reported bird die-offs as early as late June 1999, or five weeks before the first human cases were detected. If the veterinary investigation had begun earlier and been pursued more aggressively, it is possible that the human epidemic could have been mitigated or even averted.
• Throughout the outbreak investigation, communication among the 18 participating local, state, and federal agencies was complex and difficult, and was achieved primarily through conference calls lasting several hours.
• The various city, state, and federal laboratories involved in the case used different diagnostic techniques, making it difficult to compare results.[6]

This experience indicates the need for better information-sharing at all levels, as well as a common database for disease surveillance and laboratory tracking.

Bridging the Gaps

Today, the U.S. response to a serious epidemic resulting from an emerging infectious disease or an act of bioterrorism would be seriously constrained by poor communication and coordination among the diverse array of federal, state, county, and city agencies responsible for medical care, public health, animal health, law enforcement, and intelligence collection. Efforts to improve interagency coordination face formidable obstacles, including fragmented jurisdiction and differences in organizational mission and culture among the various players.

In particular, it is essential to bridge three critical gaps that would seriously impede the nation's ability to detect and respond rapidly to unusual outbreaks of disease. These disconnects exist between: (1) primary care providers and the public health system, (2) the human and animal health communities, and (3) public health experts and intelligence analysts.

The Gap Between Primary Care Providers and Public Health Departments

Disease surveillance systems in the United States are patchy in their coverage, and most rely on reporting by primary health care providers. In the most common type of surveillance, physicians and nurse-practitioners are required to report certain infectious diseases or "syndromes" (undiagnosed clusters of symptoms) to local health departments. Even when disease or syndromic reporting is mandatory, however, it is often incomplete. Doctors may be too busy to comply, or they may simply not know to whom to report.

In the case of West Nile virus, the system worked: reporting by an alert physician was key to the early detection of the outbreak. Nevertheless, a bioterrorist attack or a serious natural outbreak would permit little margin for error. If health-care providers are to be effective sentinels of an epidemic, they must have the necessary training and professional awareness to include the possibility of emerging infections and bioterrorism in their differential diagnosis. In addition, they must have direct communication channels to the public health department and be able to report cases at any time, day or night.

The Gap Between the Human and Animal Health Communities

Many emerging infectious diseases and putative bioterrorist agents are "zoonotic," meaning that they originate in animals but can also infect humans. Examples of zoonotic diseases that have been developed as biological warfare agents include anthrax, tularemia, brucellosis, plague, and Venezuelan equine encephalitis. In addition, many natural epidemics have begun in wild or domesticated animals and then spread to humans, including the outbreaks of bubonic plague in India, Sin Nombre virus in the U.S. Southwest, Nipah virus in Malaysia, avian influenza in Hong Kong, and West Nile virus in New York City.

Given the considerable overlap of animal and human pathogens, animals can serve as useful "sentinels" for outbreaks of zoonotic diseases. Sheep, for example, are far more sensitive to anthrax infection than humans. Nevertheless, the West Nile investigation exposed a major gap between the veterinary and public health communities. Although the key to identifying the causative agent lay in merging information from the parallel investigations of the bird and human outbreaks, communication between animal health and public health agencies was poor. What limited cooperation occurred was the result of informal personal relationships rather than official coordinating mechanisms.

This disconnect arose from the fact that the expert communities that address the health of people, domesticated animals, and wildlife are separated organizationally, geographically, and jurisdictionally—despite the fact that infectious diseases do not respect these artificial boundaries. State and local veterinary agencies focus on the health of domestic pets, horses, livestock, and other economically important species, but they rarely communicate with agencies involved in safeguarding human health. Low priority and funding are devoted to the health of wildlife, particularly non-endangered species such as crows and rats, which are the responsibility of parks departments and animal control officers. Monitoring the health of zoo animals is another "gray area" with no clear leadership, and only six zoos in the United States employ full-time veterinary pathologists.[7]

The 1999 outbreak of West Nile encephalitis in New York City indicated that outbreaks of zoonotic disease in wildlife and zoo animal populations could provide early warning of an impending human epidemic. In 2001, the CDC agreed to fund a pilot project for monitoring the spread of West Nile virus by testing blood and tissue specimens from zoo animals, as well as dead birds and other wildlife found on zoo property. A centralized database will be established to summarize the results, which will be made available to the public health surveillance system. For the project to be effective, the participating zoo pathologists must build a relationship with local public health officials, and the zoo data must be reliable (using a validated diagnostic methodology), consistent, and reported in a timely fashion. If this pilot program is successful, it could serve as the basis for further interaction between the zoo and public health communities for the surveillance of other zoonotic diseases.[8]

The Gap Between the Public Health Specialists and Intelligence Analysts

The dual threats of emerging infections and bioterrorism pose major conceptual and technical challenges for the U.S. intelligence community, such as distinguishing between a natural outbreak of an emerging disease and the deliberate release of a pathogen by terrorists. In 1984, for example, members of the Oregon-based Rajneeshee cult used salmonella bacteria to contaminate ten restaurant salad bars in a trial run of a scheme to manipulate the outcome of a local election by making large numbers of voters too sick to go to the polls. After 751 people fell ill with food poisoning, public health investigators concluded initially that the outbreak had resulted from natural sources. The true cause did not emerge until a year later, when a cult member confessed to the crime.[9]

During the West Nile investigation, the belated discovery that the causative virus had originated in the Middle East reportedly raised red flags with biological warfare analysts at the Central Intelligence Agency (CIA). The reason was an eerie coincidence. In April 1999, Mikhael Ramadan, a self-declared Iraqi defector who claimed to have worked as a body-double for Saddam Hussein, published a memoir in England titled In the Shadow of Saddam in which he asserted that in 1997, the Iraqi leader had ordered the development of a highly virulent strain of West Nile virus as a bioterrorist weapon.[10] Additional concern was raised by the fact that during the 1980s, the CDC had shipped an Israeli strain of West Nile virus to a microbiologist in Basra, Iraq, ostensibly for public health research.[11] Nevertheless, further analysis turned up no evidence that the Iraqis had developed West Nile virus as a biological weapon.[12]

The ability of the CIA to assess whether the West Nile outbreak was a deliberate attack was hampered by the agency's lack of technical expertise: few intelligence analysts have a solid grounding in infectious diseases or epidemiology. Trained epidemiologists would have recognized immediately that West Nile virus was a poor candidate as a bioterrorist weapon because it causes neurological injury and death in only about 5 to 10 percent of those infected, mainly children, the elderly, and those with a weakened immune system. Moreover, because the virus is transmitted to humans by mosquitoes, the putative terrorists would have had to import virus-infected insects, release them, and wait for the disease to spread -- an unlikely scenario.

Although the CIA has recruited a few microbiologists and other scientists for its analytical staff, this solution is not optimal because scientists need to interact freely with colleagues from other countries if they are to remain current and well informed. A better approach would be to provide for routine exchanges of people and training between U.S. public health and intelligence agencies, but differences in organizational culture have impeded collaboration in analyzing bioterrorist threats. For intelligence specialists, working closely with medical doctors and epidemiologists pose risks to the security and effectiveness of their operations. CDC epidemiologists, for their part, see themselves as members of the international scientific community, publish their research results, and interact with colleagues from politically sensitive countries; few are cleared for classified information or have access to encrypted phone and fax lines. Public health experts also worry that cooperation with defense, law enforcement, or intelligence agencies could taint their public image. Indeed, any link between the CDC and the U.S. intelligence community, however innocent, could undermine the ability of epidemiologists to investigate natural disease outbreaks in foreign countries.

Policy Recommendations

New policies are needed to bridge the three gaps identified above in order to improve the nation's preparedness for rapidly identifying and containing outbreaks of disease associated either with emerging infections or bioterrorism.

Bridging the Gap Between Primary Care Providers and Public Health Departments

• The Department of Health and Human Services (DHHS) should expand the national program of awareness training for primary health care providers. To ensure timely detection of an unusual outbreak of disease, general practitioners, emergency-room physicians, and nurse-practitioners must be familiar with the signs and symptoms of exotic diseases that they would not normally encounter in their medical practice. Professional medical societies, physician-oriented web sites, and continuing medical education programs should offer training and refresher courses in the diagnosis and treatment of bioterrorist agents. Such courses might eventually be made a prerequisite for medical licensing or board certification.

• DHHS should provide grants to state and local public health agencies to establish simple reporting mechanisms and clear communication channels between medical practitioners and city, state, or county public health departments, including 24-hour telephone or e-mail "hot lines." To respond effectively when doctors call, day or night, state and local health departments will need additional funds to hire more staff members with expertise in infectious diseases, epidemiology, and information technology.

• DHHS should increase the number of clinical laboratories associated with public health departments around the country that are capable of diagnosing exotic diseases, including suspected bioterrorist agents. Standardized testing protocols should be developed so that laboratories can easily exchange and compare diagnostic findings.

• In conjunction with the Department of Defense, DHHS should improve basic and applied research on bioterrorist threat agents by increasing funding for this purpose. Knowledge of the pathophysiology, virulence factors, immunology, and genomic structure of disease agents is vital for the development of improved diagnostic tests, therapeutics, and vaccines. Yet such knowledge is limited for the roughly two dozen classical biological warfare agents, and almost nonexistent for more than 100 microbial pathogens of potential bioterrorist concern.

• DHHS should facilitate prompt and accurate disease reporting by expanding its current efforts to establish an electronic infrastructure for this purpose at the city, county, and state levels. At present, few cities have established electronic systems for the exchange of surveillance data, and roughly half the public health agencies in the United States are not connected to the Internet. Also needed is a national electronic information system for exchanging disease-reporting data between state health departments and the CDC.

• DHHS should attempt to attract more talented individuals into the public health field by offering mid-career fellowships and internships for medical doctors, both at CDC and at public health departments around the country.

• CDC should assist hospitals to incorporate bioterrorist scenarios in their emergency response plans and to carry out frequent dress rehearsals.

Bridging the Gap Between the Human and Animal Health Communities

• If the pilot zoo surveillance project for West Nile virus is successful, DHHS and the U.S. Department of Agriculture (USDA) should expand this program into a veterinary surveillance network in which unusual patterns of zoonotic disease in livestock, zoo animals, or wild animals are reported promptly to state and local public health departments. In some cases, susceptible species living in a city zoo could serve as "sentinels" of a covert bioterrorist attack against the urban population.

• DHHS and USDA should support improved communications infrastructure between veterinary agencies and public health departments, including telephone and e-mail hot lines, so that unusual outbreaks of zoonotic disease in animals can be reported to the appropriate public health authorities.

• DHHS should fund more epidemiological research on the complex relationships between human and animal health. Already, the West Nile outbreak has served as a catalyst for greater interdisciplinary cooperation among veterinarians, physicians, ecologists, and wildlife biologists.

Bridging the Gap Between Public Health Specialists and Intelligence Analysts

• The U.S. intelligence community should recruit more individuals with advanced training in microbiology, infectious disease, and epidemiology to work as intelligence analysts focusing on biowarfare and bioterrorist threats. In particular, the Defense Intelligence Agency's Armed Forces Medical Intelligence Center (AFMIC), the one intelligence organization specializing in infectious diseases, should be expanded by hiring more technically trained staff. Individuals with experience in the biotechnology industry are also needed to detect the subtle indicators of clandestine biological weapons production, particularly at dual-use facilities such as vaccine plants.

• DHHS should establish formal exchanges of people and training between public health agencies such as the CDC and federal intelligence services such as the CIA, the Defense Intelligence Agency (DIA), the National Security Agency (NSA), and the Federal Bureau of Investigation (FBI). To this end, DHHS should create a cadre of specialists in public health and biomedicine who have security clearances and access to secure communications, such as encrypted phone, fax, and videoconferencing facilities. These experts could then provide technical advice to intelligence analysts as needed concerning suspicious disease outbreaks that could be the result of covert biological weapons use.

• CDC should establish a reporting mechanism so that unusual outbreaks of disease in the United States detected by the Epidemic Intelligence Service (EIS) are routinely reported to the FBI and other law-enforcement agencies.

In conclusion, the natural emergence of a deadly and contagious infectious disease such as the Spanish Flu of 1918, or the deliberate release of anthrax or some other pathogen as an act of bioterrorism, could result in a serious loss of life and social disruption. Unless corrected, the communication gaps that currently exist among the U.S. medical, public health, animal health, and intelligence communities could seriously delay detection of the resulting disease outbreak and impede the prompt response needed to minimize its medical impact and social consequences.

Bridging these gaps will be essential if the nation is to be better prepared to deal with the dual threats posed by emerging infections and bioterrorism. The good news is that despite the anxieties we all share today about this issue, the U.S. government can take practical steps to reduce the threat. Improved infectious disease surveillance, combined with other preparedness measures and continued research, may make it possible in the not-too-distant future to render biological weapons in the hands of terrorists—to borrow a phrase from President Ronald Reagan—"impotent and obsolete."

[1] This testimony draws extensively on the following publication: Jonathan B. Tucker and Robert P. Kadlec, "Infectious Disease and National Security," Strategic Review, vol. XXIX, no. 2 (Spring 2001), pp. 12-20.

[2] Rick Weiss and Ellen Nakashima, "Biological Attack Concerns Spur Warnings," Washington Post, September 22, 2001, p. A04.

[3] National Intelligence Council, The Global Infectious Disease Threat and Its Implications for the United States, NIE 99-17D, January 2000 [www.cia.gov/cia/publications/nie/report/nie99-17d.html].

[4] Chemical and Biological Arms Control Institute, Bioterrorism in the United States: Threat, Preparedness, and Response, Executive Summary, November 2000, p. 12.

[5] Jennifer Steinhauer and Judith Miller, "In New York Outbreak, Glimpses of Gaps in Biological Defenses," New York Times, October 11, 1999.

[6] Marcelle Layton, M.D., M.P.H., "Outbreak Surveillance and Management at the State and Local Level: Current Realities," presentation at the Second National Symposium on Medical and Public Health Response to Bioterrorism, Washington, D.C., November 28, 2000, transcript.

[7] Tracey McNamara, Bronx Zoo, presentation at Workshop on Agro-Terrorism, Cornell University, November 13, 2000.

[8] Tracey S. McNamara and Dominic Travis, Project Co-coordinators, Surveillance for West Nile Virus in Zoological Institutions: Report of a Workshop, June 21-22, 2001, Lincoln Park Zoo, Chicago.

[9] W. Seth Carus, "The Rajneeshees (1984)," in Jonathan B. Tucker, ed., Toxic Terror: Assessing Terrorist Use of Chemical and Biological Weapons (Cambridge, Mass.: MIT Press, 2000), pp. 115-137.

[10] Richard Preston, "West Nile Mystery," The New Yorker, October 18-25, 1999, pp. 90-108.

[11] Jonathan B. Tucker, "Lessons of Iraq's Biological Warfare Programme," Arms Control/Contemporary Security Policy, vol. 14, no. 3 (December 1993), p. 238.

[12] Vernon Loeb, "CIA Finds No Sign N.Y. Virus Was an Attack," Washington Post, October 12, 1999, p. A2.