The U.S. national civilian vulnerability to the deliberate use of biological and chemical agents has been highlighted by recognition of substantial biological weapons development programs and arsenals in foreign countries, attempts to acquire or possess biological agents by militants, and high-profile terrorist attacks. Evaluation of this vulnerability has focused on the role public health will have detecting and managing the probable covert biological terrorist incident with the realization that the U.S. local, state, and federal infrastructure is already strained as a result of other important public health problems. In partnership with representatives for local and state health departments, other federal agencies, and medical and public health professional associations, CDC has developed a strategic plan to address the deliberate dissemination of biological or chemical agents. The plan contains recommendations to reduce U.S. vulnerability to biological and chemical terrorism -preparedness planning, detection and surveillance, laboratory analysis, emergency response, and communication systems. Training and research are integral components for achieving these recommendations. Success of the plan hinges on strengthening the relationships between medical and public health professionals and on building new partnerships with emergency management, the military, and law enforcement professionals.# INTRODUCTION
An act of biological or chemical terrorism might range from dissemination of aerosolized anthrax spores to food product contamination, and predicting when and how such an attack might occur is not possible. However, the possibility of biological or chemical terrorism should not be ignored, especially in light of events during the past 10 years (e.g., the sarin gas attack in the Tokyo subway  and the discovery of military bioweapons programs in Iraq and the former Soviet Union ). Preparing the nation to address this threat is a formidable challenge, but the consequences of being unprepared could be devastating.
The public health infrastructure must be prepared to prevent illness and injury that would result from biological and chemical terrorism, especially a covert terrorist attack. As with emerging infectious diseases, early detection and control of biological or chemical attacks depends on a strong and flexible public health system at the local, state, and federal levels. In addition, primary health-care providers throughout the United States must be vigilant because they will probably be the first to observe and report unusual illnesses or injuries.

# MMWR April 21, 2000
This report is a summary of the recommendations made by CDC's Strategic Planning Workgroup in Preparedness and Response to Biological and Chemical Terrorism: A Strategic Plan (CDC, unpublished report, 2000 ), which outlines steps for strengthening public health and health-care capacity to protect the United States against these dangers. This strategic plan marks the first time that CDC has joined with law enforcement, intelligence, and defense agencies in addition to traditional CDC partners to address a national security threat.
As a reflection of the need for broad-based public health involvement in terrorism preparedness and planning, staff from CDC's centers, institute, and offices participated in developing the strategic plan, including the The Agency for Toxic Substances and Disease Registry (ATSDR) is also participating with CDC in this effort and will provide expertise in the area of industrial chemical terrorism. In this report, the term CDC includes ATSDR when activities related to chemical terrorism are discussed. In addition, colleagues from local, state, and federal agencies; emergency medical services (EMS); professional societies; universities and medical centers; and private industry provided suggestions and constructive criticism.
Combating biological and chemical terrorism will require capitalizing on advances in technology, information systems, and medical sciences. Preparedness will also require a re-examination of core public health activities (e.g., disease surveillance) in light of these advances. Preparedness efforts by public health agencies and primary health-care providers to detect and respond to biological and chemical terrorism will have the added benefit of strengthening the U.S. capacity for identifying and controlling injuries and emerging infectious diseases.

# U.S. VULNERABILITY TO BIOLOGICAL AND CHEMICAL TERRORISM
Terrorist incidents in the United States and elsewhere involving bacterial pathogens (3 ), nerve gas (1 ), and a lethal plant toxin (i.e., ricin) (4 ), have demonstrated that the United States is vulnerable to biological and chemical threats as well as explosives. Recipes for preparing "homemade" agents are readily available (5 ), and reports of arsenals of military bioweapons (2 ) raise the possibility that terrorists might have access to highly dangerous agents, which have been engineered for mass dissemination as small-particle aerosols. Such agents as the variola virus, the causative agent of smallpox, are highly contagious and often fatal. Responding to large-scale outbreaks caused q Because the initial detection of a covert biological or chemical attack will probably occur at the local level, disease surveillance systems at state and local health agencies must be capable of detecting unusual patterns of disease or injury, including those caused by unusual or unknown threat agents.
- Because the initial response to a covert biological or chemical attack will probably be made at the local level, epidemiologists at state and local health agencies must have expertise and resources for responding to reports of clusters of rare, unusual, or unexplained illnesses.
by these agents will require the rapid mobilization of public health workers, emergency responders, and private health-care providers. Large-scale outbreaks will also require rapid procurement and distribution of large quantities of drugs and vaccines, which must be available quickly.

# OVERT VERSUS COVERT TERRORIST ATTACKS
In the past, most planning for emergency response to terrorism has been concerned with overt attacks (e.g., bombings). Chemical terrorism acts are likely to be overt because the effects of chemical agents absorbed through inhalation or by absorption through the skin or mucous membranes are usually immediate and obvious. Such attacks elicit immediate response from police, fire, and EMS personnel.
In contrast, attacks with biological agents are more likely to be covert. They present different challenges and require an additional dimension of emergency planning that involves the public health infrastructure (Box 1). Covert dissemination of a biological agent in a public place will not have an immediate impact because of the delay between exposure and onset of illness (i.e., the incubation period). Consequently, the first casualties of a covert attack probably will be identified by physicians or other primary healthcare providers. For example, in the event of a covert release of the contagious variola virus, patients will appear in doctors' offices, clinics, and emergency rooms during the first or second week, complaining of fever, back pain, headache, nausea, and other symptoms of what initially might appear to be an ordinary viral infection. As the disease progresses, these persons will develop the papular rash characteristic of early-stage smallpox, a rash that physicians might not recognize immediately. By the time the rash becomes pustular and patients begin to die, the terrorists would be far away and the disease disseminated through the population by person-to-person contact. Only a short window of opportunity will exist between the time the first cases are identified and a second wave of the population becomes ill. During that brief period, public health officials will need to determine that an attack has occurred, identify the organism, and prevent more casualties through prevention strategies (e.g., mass vaccination or prophylactic treatment). As person-to-person contact continues, successive waves of transmission could carry infection to other worldwide localities. These issues might also be relevant for other person-to-person transmissible etiologic agents (e.g., plague or certain viral hemorrhagic fevers).

# BOX 1. Local public health agency preparedness
Certain chemical agents can also be delivered covertly through contaminated food or water. In 1999, the vulnerability of the food supply was illustrated in Belgium, when chickens were unintentionally exposed to dioxin-contaminated fat used to make animal feed (6 ). Because the contamination was not discovered for months, the dioxin, a cancer-causing chemical that does not cause immediate symptoms in humans, was probably present in chicken meat and eggs sold in Europe during early 1999. This incident underscores the need for prompt diagnoses of unusual or suspicious health problems in animals as well as humans, a lesson that was also demonstrated by the recent outbreak of mosquitoborne West Nile virus in birds and humans in New York City in 1999. The dioxin episode also demonstrates how a covert act of foodborne biological or chemical terrorism could affect commerce and human or animal health.

# FOCUSING PREPAREDNESS ACTIVITIES
Early detection of and response to biological or chemical terrorism are crucial. Without special preparation at the local and state levels, a large-scale attack with variola virus, aerosolized anthrax spores, a nerve gas, or a foodborne biological or chemical agent could overwhelm the local and perhaps national public health infrastructure. Large numbers of patients, including both infected persons and the "worried well," would seek medical attention, with a corresponding need for medical supplies, diagnostic tests, and hospital beds. Emergency responders, health-care workers, and public health officials could be at special risk, and everyday life would be disrupted as a result of widespread fear of contagion.
Preparedness for terrorist-caused outbreaks and injuries is an essential component of the U.S. public health surveillance and response system, which is designed to protect the population against any unusual public health event (e.g., influenza pandemics, contaminated municipal water supplies, or intentional dissemination of Yersinia pestis , the causative agent of plague ). The epidemiologic skills, surveillance methods, diagnostic techniques, and physical resources required to detect and investigate unusual or unknown diseases, as well as syndromes or injuries caused by chemical accidents, are similar to those needed to identify and respond to an attack with a biological or chemical agent. However, public health agencies must prepare also for the special features a terrorist attack probably would have (e.g., mass casualties or the use of rare agents) (Boxes 2-5). Terrorists might use combinations of these agents, attack in more than one location simultaneously, use new agents, or use organisms that are not on the critical list (e.g., common, drug-resistant, or genetically engineered pathogens). Lists of critical biological and chemical agents will need to be modified as new information becomes available. In addition, each state and locality will need to adapt the lists to local conditions and preparedness needs by using the criteria provided in CDC's strategic plan.
Potential biological and chemical agents are numerous, and the public health infrastructure must be equipped to quickly resolve crises that would arise from a biological or chemical attack. However, to best protect the public, the preparedness efforts must be focused on agents that might have the greatest impact on U.S. health and security, especially agents that are highly contagious or that can be engineered for widespread dissemination via small-particle aerosols. Preparing the nation to address these dangers is a major challenge to U.S. public health systems and health-care providers. Early detection requires increased biological and chemical terrorism awareness among frontline health-care providers because they are in the best position to report suspicious illnesses and injuries. Also, early detection will require improved communication systems between those providers and public health officials. In addition, state and local

# Category C
Third highest priority agents include emerging pathogens that could be engineered for mass dissemination in the future because of q availability; q ease of production and dissemination; and q potential for high morbidity and mortality and major health impact.

# Preparedness and Prevention
Detection, diagnosis, and mitigation of illness and injury caused by biological and chemical terrorism is a complex process that involves numerous partners and activities. Meeting this challenge will require special emergency preparedness in all cities and q pulmonary agents, -phosgene, -chlorine, -vinyl chloride; q incapacitating agents, -BZ (3-quinuclidinyl benzilate); q pesticides, persistent and nonpersistent; q dioxins, furans, and polychlorinated biphenyls (PCBs); q explosive nitro compounds and oxidizers, -ammonium nitrate combined with fuel oil; q flammable industrial gases and liquids, -gasoline, -propane; q poison industrial gases, liquids, and solids, -cyanides, -nitriles; and q corrosive industrial acids and bases, -nitric acid, -sulfuric acid. Because of the hundreds of new chemicals introduced internationally each month, treating exposed persons by clinical syndrome rather than by specific agent is more useful for public health planning and emergency medical response purposes. Public health agencies and first responders might render the most aggressive, timely, and clinically relevant treatment possible by using treatment modalities based on syndromic categories (e.g., burns and trauma, cardiorespiratory failure, neurologic damage, and shock). These activities must be linked with authorities responsible for environmental sampling and decontamination.

# BOX 5. (Continued) Chemical agents
states. CDC will provide public health guidelines, support, and technical assistance to local and state public health agencies as they develop coordinated preparedness plans and response protocols. CDC also will provide self-assessment tools for terrorism preparedness, including performance standards, attack simulations, and other exercises. In addition, CDC will encourage and support applied research to develop innovative tools and strategies to prevent or mitigate illness and injury caused by biological and chemical terrorism.

# Detection and Surveillance
Early detection is essential for ensuring a prompt response to a biological or chemical attack, including the provision of prophylactic medicines, chemical antidotes, or vaccines. CDC will integrate surveillance for illness and injury resulting from biological and chemical terrorism into the U.S. disease surveillance systems, while developing new mechanisms for detecting, evaluating, and reporting suspicious events that might represent covert terrorist acts. As part of this effort, CDC and state and local health agencies will form partnerships with front-line medical personnel in hospital emergency departments, hospital care facilities, poison control centers, and other offices to enhance detection and reporting of unexplained injuries and illnesses as part of routine surveillance mechanisms for biological and chemical terrorism.

# Diagnosis and Characterization of Biological and Chemical Agents
CDC and its partners will create a multilevel laboratory response network for bioterrorism (LRNB). That network will link clinical labs to public health agencies in all states, districts, territories, and selected cities and counties and to state-of-the-art facilities that can analyze biological agents (Figure 1). As part of this effort, CDC will transfer diagnostic technology to state health laboratories and others who will perform initial testing. CDC will also create an in-house rapid-response and advanced technology (RRAT) laboratory. This laboratory will provide around-the-clock diagnostic confirmatory and reference support for terrorism response teams. This network will include the regional chemical laboratories for diagnosing human exposure to chemical agents and provide links with other departments (e.g., the U.S. Environmental Protection Agency, which is responsible for environmental sampling).

# Response
A comprehensive public health response to a biological or chemical terrorist event involves epidemiologic investigation, medical treatment and prophylaxis for affected persons, and the initiation of disease prevention or environmental decontamination measures. CDC will assist state and local health agencies in developing resources and expertise for investigating unusual events and unexplained illnesses. In the event of a confirmed terrorist attack, CDC will coordinate with other federal agencies in accord with Presidential Decision Directive (PDD) 39. PDD 39 designates the Federal Bureau of Investigation as the lead agency for the crisis plan and charges the Federal Emergency Management Agency with ensuring that the federal response management is adequate to respond to the consequences of terrorism (8 ). If requested by a state health agency, CDC will deploy response teams to investigate unexplained or suspicious illnesses or

# Level D laboratories
Agentspecific laboratory

# Rapid-response and advanced technology laboratory

# Level C laboratory

# Level B laboratory

# Level A laboratory Specimen testing and referral

# Training and consultation

# Agentspecific laboratory
Agentspecific laboratory

# Functional Levels of the Laboratory Response Network for Bioterrorism
Level A: Early detection of intentional dissemination of biological agents -Level A laboratories will be public health and hospital laboratories with low-level biosafety facilities. Level A laboratories will use clinical data and standard microbiological tests to decide which specimens and isolates should be forwarded to higher level biocontainment laboratories. Level A laboratory staff will be trained in the safe collection, packaging, labeling, and shipping of samples that might contain dangerous pathogens.

# Level B:
Core capacity for agent isolation and presumptive-level testing of suspect specimens -Level B laboratories will be state and local public health agency laboratories that can test for specific agents and forward organisms or specimens to higher level biocontainment laboratories. Level B laboratories will minimize false positives and protect Level C laboratories from overload. Ultimately, Level B laboratories will maintain capacity to perform confirmatory testing and characterize drug susceptibility.
Level C: Advanced capacity for rapid identification -Level C laboratories, which could be located at state health agencies, academic research centers, or federal facilities, will perform advanced and specialized testing. Ultimately, Level C laboratories will have the capacity to perform toxicity testing and employ advanced diagnostic technologies (e.g., nucleic acid amplification and molecular fingerprinting). Level C laboratories will participate in the evaluation of new tests and reagents and determine which assays could be transferred to Level B laboratories.
Level D: Highest level containment and expertise in the diagnosis of rare and dangerous biological agents -Level D laboratories will be specialized federal laboratories with unique experience in diagnosis of rare diseases (e.g., smallpox and Ebola). Level D laboratories also will develop or evaluate new tests and methods and have the resources to maintain a strain bank of biological agents. Level D laboratories will maintain the highest biocontainment facilities and will be able to conduct all tests performed in Level A, B, and C laboratories, as well as additional confirmatory testing and characterization, as needed. They will also have the capacity to detect genetically engineered agents. unusual etiologic agents and provide on-site consultation regarding medical management and disease control. To ensure the availability, procurement, and delivery of medical supplies, devices, and equipment that might be needed to respond to terrorist-caused illness or injury, CDC will maintain a national pharmaceutical stockpile.

# Communication Systems
U.S. preparedness to mitigate the public health consequences of biological and chemical terrorism depends on the coordinated activities of well-trained health-care and public health personnel throughout the United States who have access to up-to-the minute emergency information. Effective communication with the public through the news media will also be essential to limit terrorists' ability to induce public panic and disrupt daily life. During the next 5 years, CDC will work with state and local health agencies to develop a) a state-of-the-art communication system that will support disease surveillance; b) rapid notification and information exchange regarding disease outbreaks that are possibly related to bioterrorism; c) dissemination of diagnostic results and emergency health information; and d) coordination of emergency response activities. Through this network and similar mechanisms, CDC will provide terrorism-related training to epidemiologists and laboratorians, emergency responders, emergency department personnel and other front-line health-care providers, and health and safety personnel.

# PARTNERSHIPS AND IMPLEMENTATION

# Preparedness and Prevention
- Maintain a public health preparedness and response cooperative agreement that provides support to state health agencies who are working with local agencies in developing coordinated bioterrorism plans and protocols. q Establish a national public health distance-learning system that provides biological and chemical terrorism preparedness training to health-care workers and to state and local public health workers. q Disseminate public health guidelines and performance standards on biological and chemical terrorism preparedness planning for use by state and local health agencies.

# Detection and Surveillance
- Strengthen state and local surveillance systems for illness and injury resulting from pathogens and chemical substances that are on CDC's critical agents list. q Develop new algorithms and statistical methods for searching medical databases on a real-time basis for evidence of suspicious events. q Establish criteria for investigating and evaluating suspicious clusters of human or animal disease or injury and triggers for notifying law enforcement of suspected acts of biological or chemical terrorism.

# Diagnosis and Characterization of Biological and Chemical Agents
- Establish a multilevel laboratory response network for bioterrorism that links public health agencies to advanced capacity facilities for the identification and reporting of critical biological agents. q Establish regional chemical terrorism laboratories that will provide diagnostic capacity during terrorist attacks involving chemical agents. q Establish a rapid-response and advanced technology laboratory within CDC to provide around-the-clock diagnostic support to bioterrorism response teams and expedite molecular characterization of critical biological agents.

# Response
- Assist state and local health agencies in organizing response capacities to rapidly deploy in the event of an overt attack or a suspicious outbreak that might be the result of a covert attack. q Ensure that procedures are in place for rapid mobilization of CDC terrorism response teams that will provide on-site assistance to local health workers, security agents, and law enforcement officers. q Establish a national pharmaceutical stockpile to provide medical supplies in the event of a terrorist attack that involves biological or chemical agents.

# RECOMMENDATIONS
Implementing CDC's strategic preparedness and response plan by 2004 will ensure the following outcomes: q U.S. public health agencies and health-care providers will be prepared to mitigate illness and injuries that result from acts of biological and chemical terrorism.
- Public health surveillance for infectious diseases and injuries -including events that might indicate terrorist activity -will be timely and complete, and reporting of suspected terrorist events will be integrated with the evolving, comprehensive networks of the national public health surveillance system.
- The national laboratory response network for bioterrorism will be extended to include facilities in all 50 states. The network will include CDC's environmental health laboratory for chemical terrorism and four regional facilities.
- State and federal public health departments will be equipped with state-of-the-art tools for rapid epidemiological investigation and control of suspected or confirmed acts of biological or chemical terrorism, and a designated stock of terrorism-related medical supplies will be available through a national pharmaceutical stockpile.
- A cadre of well-trained health-care and public health workers will be available in every state. Their terrorism-related activities will be coordinated through a rapid and efficient communication system that links U.S. public health agencies and their partners.

# CONCLUSION
Recent threats and use of biological and chemical agents against civilians have exposed U.S. vulnerability and highlighted the need to enhance our capacity to detect and control terrorist acts. The U.S. must be protected from an extensive range of critical biological and chemical agents, including some that have been developed and stockpiled for military use. Even without threat of war, investment in national defense ensures preparedness and acts as a deterrent against hostile acts. Similarly, investment in the Communication Systems q Establish a national electronic infrastructure to improve exchange of emergency health information among local, state, and federal health agencies. q Implement an emergency communication plan that ensures rapid dissemination of health information to the public during actual, threatened, or suspected acts of biological or chemical terrorism. q Create a website that disseminates bioterrorism preparedness and training information, as well as other bioterrorism-related emergency information, to public health and health-care workers and the public. public health system provides the best civil defense against bioterrorism. Tools developed in response to terrorist threats serve a dual purpose. They help detect rare or unusual disease outbreaks and respond to health emergencies, including naturally occurring outbreaks or industrial injuries that might resemble terrorist events in their unpredictability and ability to cause mass casualties (e.g., a pandemic influenza outbreak or a large-scale chemical spill). Terrorism-preparedness activities described in CDC's plan, including the development of a public health communication infrastructure, a multilevel network of diagnostic laboratories, and an integrated disease surveillance system, will improve our ability to investigate rapidly and control public health threats that emerge in the twenty first century.

# Recommendations and Reports

# Continuing Education Activity
Sponsored by CDC

# ACCREDITATION Continuing Medical Education (CME). CDC is accredited by the Accreditation Council for Continuing Medical Education (ACCME)
to provide continuing medical education for physicians. CDC designates this educational activity for a maximum of 1.0 hour in category 1 credit towards the AMA Physician's Recognition Award. Each physician should claim only those hours of credit that he/she actually spent in the educational activity.

# Continuing Nursing Education (CNE).
This activity for 1.2 contact hours is provided by CDC, which is accredited as a provider of continuing education in nursing by the American Nurses Credentialing Center's Commission on Accreditation.