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Bioterrorism: Are We Prepared?

Joseph M. Henderson


Biological or chemical agents used in terrorism:

  • are relatively easy to produce and use
  • are difficult to contain, particularly biological ones
  • could cause large-scale health problems or fatalities
  • stretch our healthcare response capabilities

November 2000

Note: Because some of the information in this article may be outdated, it has been archived.

What is bioterrorism?

Biological or chemical agents can be used for terrorism.

A wanted poster in Japan, with photos of people wanted in connection with the sarin gas attack on the Tokyo subway on March 20, 1995. Source: Creative Commons.

Henderson: Bioterrorism is the dissemination of biological agents such as Anthrax, Smallpox, or chemicals such as Sarin gas (which was used by the Aum Shinryko Cult in Tokyo in 1995 killing 12 people and injuring hundreds), into the population by an individual or group intended to cause illness, injury or death. Since the specific diseases and chemicals used by terrorist groups could potentially cause significant diseases or injuries, they are the focus of national planning efforts to prepare for and respond to acts of bioterrorism. Keep in mind that bioterrorism is seen as a “High Consequence - Low Probability” event.

These agents could cause large-scale damage.

How significant a threat is it?

Henderson: We think bioterrorism poses a very serious threat to the population in general. Although, we in public health are not privy to intelligence information that would provide significant details regarding terrorist groups and their intentions, we do know that if one of these agents was introduced into the population it could cause considerable damage.

What kind of biological agents could be used by terrorists?

Henderson: The CDC has three categories for critical biological agents:

Category A agents could cause the most deaths.

Category A: Smallpox, Anthrax, Plague, Botulism, Tularaemia, Filoviruses (e.g., Ebola), and Arenaviruses (e.g., Lassa fever). These organisms are grouped into the A list 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
  • require special action for public health preparedness
Category B agents can only be identified from victim diagnosis.

Category B:

Q fever, Brucellosis, Glanders, Alphaviruses (e.g., Equine Encephalomyelitis), Ricin toxin from castor beans, Epsilon toxin, Staph enterotoxin B, and food/water-borne pathogens. The organisms in this group:

  • are moderately easy to disseminate
  • cause moderate morbidity and low mortality
  • require specific diagnostic capacity and enhanced disease surveillance
Category C has the potential to cause major damage.

Category C:


Tick-borne encephalitis (TBE) is a viral infection of the central nervous system affecting humans and most other mammals. It is caused by ixodes ricinus. TBE could be used for bioterrorism. Photo: Roxirras Blogg.

Nipah virus, Hantaviruses, tickborne Hemorrhagic Fever viruses, tickborne Encephalitis viruses, Yellow Fever, and multidrug-resistant Tuberculosis. These organisms fall into the third group because of:

  • availability
  • ease of production and dissemination
  • potential for high morbidity and mortality and major health impact

Smallpox and Anthrax at are at the top of your list. Why?

These agents are transmitted person-to-person.
Inhaled Anthrax, if not treated quickly, will most likely kill its victim.
There is not enough vaccine to treat an outbreak of Smallpox.

Henderson: Anthrax and Smallpox along with Viral Hemorrhagic Fevers, Tularemia, Botulism toxins, and Plague top our list of critical diseases because they:

  • can be easily transmitted person-to-person
  • cause high mortality, with potential for major public health impact
  • might cause public panic and social disruption
  • require special action for public health preparedness

Anthrax and Smallpox have potential for casualties on a large scale. Both are highly lethal. For example, the death rate for inhaled Anthrax, if untreated before serious symptoms develop, exceeds 90% and in the case of Smallpox, up to 30% for people who are not immunized for the disease. In addition, both agents can survive for a long time under the right conditions. Availability of vaccines for either of these infectious diseases is limited.

In the case of Smallpox, we know that there still are quantities of the live virus in the United States and we believe some quantities may exist in the old Soviet Union. In addition, we only have a limited supply of Smallpox vaccine currently available but we have signed a contract with OraVax out of Cambridge, MA to begin developing a new Smallpox vaccine.

Can an ordinary person obtain information easily about chemical or biological agents?

The Internet has enough information to assemble some agents.

Henderson: I think so. The Internet provides a vast amount of information on these diseases. Even though we recognize the Internet as being a valuable tool for finding information this can be used for both good and bad purposes when it comes to bioterrorism. I don’t think the process would be that easy for someone to find information but if enough time was spent on the Internet I think they could find a substantial amount of information pertaining to infectious diseases and chemical agents.

How well is the U.S. prepared for a bioterrorist attack?

Henderson: We are much better prepared today than we were two years ago thanks in large part to the funds appropriated by Congress to support federal, state, and local bioterrorism preparedness and response efforts.

Last May, CDC participated in a national exercise sponsored by the Department of Justice and the Federal Emergency Management Agency called Top Off for top officials.

Nationwide simulated exercises help us improve our preparedness.
  • The intent of this exercise was to see how cabinet level officials collaborated to respond to weapons of mass destruction event.
  • For this exercise, CDC focused most of our resources on the simulated Plague outbreak in Denver, CO although we were also involved in a simulated mustard gas release in Portsmouth, NH and a simulated radiological incident in the greater Washington, D.C. area.
  • We learned many lessons from this exercise that has resulted in significant improvements to CDC’s internal response capacities.

We now have a national training plan for bioterrorism preparedness and response that will enhance our own staff competencies, the recognition that we need to establish an emergency operations center for infectious diseases control here at CDC, and a process for alerting state and local health agencies about bioterrorist events or other public health emergencies.

However, we have a considerable amount of work yet to be completed at the state and local public health levels of government. I believe that the work we will embark on in this coming year will help continue to build this needed public health infrastructure. Keep in mind that we still need additional funding to build this infrastructure but we are on the right path.

Is our government concerned about bioterrorism and what is it doing about the threat?

Bioterrorism has significant attention from government and agencies.

Henderson: The President and Congress have been and continue to be extremely concerned about this threat. Over the past two years a considerable amount of money has been appropriated by Congress and passed by the President to support weapons of mass destruction. Anti-terrorism is a significant component of this activity and therefore so is bioterrorism. Along with the work being done at the Centers for Disease Control, the Department of Health and Human Services is also supporting these efforts by ensuring the medical care delivery system can handle the increased caseload should a bioterrorist event occur. Other departments such as DOJ and Federal Emergency Management Agency are also working hard to ensure bioterrorism preparedness and response fits into their larger preparedness planning efforts.

What to do in an attack is not complicated. See ‘get involved’ link at the end of the interview.

What can an individual do in the event of a bioterrorist threat?

Henderson: This really depends on the agent that has been used. The most important thing is not to panic but to wait for information before making a decision. It may take a day - 24 hours - before information can be given to the public through the media. A lot of information that we are compiling at the CDC to make available to the public in the event of a threat is actually pretty basic information. Most of the things you can do if you are trying to deal with a particular organism will fit on two pages of paper.

Is our health care system prepared for a bioterrorist attack?

The health care system is inadequately prepared to deal with a major outbreak.

Henderson: I don’t think they are well prepared. In fact, the health care system is the weakest link in the chain. As a first step they need to contact local public health authorities to determine what their role should be in the context of larger local planning efforts. The challenge here is to get hospitals and other healthcare providers to understand that a large outbreak of an infectious disease will place a huge burden on them and they really need to be prepared. We learned during the Top Off exercise how fast the health care system would become saturated with a plague outbreak. The only way to resolve the problems we encountered during Top Off is to start preparing now.

How do you determine if an infectious disease is the result of terrorism or a natural outbreak?

How it starts is not as important as dealing with it.

Henderson: In public health, the source is of no consequence. We would activate our resources to control and contain public suffering the same way regardless. The difference is that we see bioterrorist events as being potentially large-scale outbreaks of a magnitude we are not accustomed to. Again, how it started is not the issue but how we control and contain it is. Keep in mind that the FBI will be very interested in how these incidents start so that they can work to ensure it doesn’t reoccur.

Joseph M. Henderson is the Chief of Program Operations for the Bioterrorism Preparedness and Response Initiative at the Centers for Disease Control and Prevention. At CDC since 1991, he served as New York State Immunization Program Director, Southeast Regional Consultant for the National Immunization Program, and Team Leader for the Registry Initiative of the National Immunization Program. Prior to CDC, he was in the U. S. Air Force developing medical response to nuclear, biological, and chemical warfare. He has a Masters degree from the University of Oklahoma. 7/03 update: Henderson is currently the Associate Director for Terrorism Preparedness and Response at the CDC.

Bioterrorism: Are We Prepared?

Agricultural bioterrorism

Read an article on our site, by Radford G. Davis, DVM, that examines the potential impact of agroterrorism on the U.S. economy.

US National Disaster Medical System (NDMS)

“Whether you are a disaster responder, public health official, emergency manager, practitioner, or just passing through our site,” you will find bioterrorism information, including emergency protocols.

Biodefense Center and Information

  • » Johns Hopkins University Center for Civilian Biodefense Strategies. At Johns Hopkins University, researchers hope to raise consciousness by Increasing national and international awareness of the medical and public health threats posed by biological weapons, thereby augmenting the potential legal, political and moral prohibitions against their use. Further, these researchers will build a knowledge base to develop a broader appreciation of the scope of the threat posed by the major biological agents and possible medical and public health responses to them through analysis of expected clinical manifestations, available treatment strategies, epidemiology, and potential methods of prophylaxis.
  • » Center for Biosecurity
    Articles, news and events from the University of Pittsburgh.

Nuclear, Biological, & Chemical Warfare

This site aims to be “the most comprehensive” links site on the the subject.

Plague Wars

A 1998 Frontline/PBS collaborative that details how viruses and bacteria have been developed/used as bioweapons and the history of bioweapons.

Virtual Museum of Bacteria

The bioterrorism feature in this virtual museum shows you pictures of different pathogens that can be used by terrorists and provides information on their health effects. Lots of links to other related web pages.

Articles by Richard Preston

Although Richard Preston is best known for his fiction novels, such asThe Hot ZoneandThe Cobra Event, his research into bioterrorism has made him very knowledgeable in the field. Both of the following Preston non-fiction articles are on-line:

Germ War: The US Record

Counter Punch, a political newspaper, describes the history of germ war in the U.S., from Cholera-infected blankets given to American Indian tribes in the 1860s to experimental vaccines given to Gulf War troops.

Weapons of destruction

The Non-Proliferation Project tracks the development of weapons of mass destruction (WMD), missile defense systems and ballistic missile programs from across the globe. Find detailed information, including charts, reports, analysis and expert meetings on WMD, conducted by the Carnegie Endowment for International Peace.

Read a book

The Cobra Event by Richard Preston (Ballantine Books, 1998) is a fiction novel but the possibilities are real and well-researched. This provocative thriller will make you wonder exactly how much bioterrorism is taking place in the real world. Preston uncovers the “invisible history” of bioweapons engineering but he does not put blame on science, presenting his scientific detectives as unsung heroes, along with the nurses and technicians who literally sacrifice their lives for medicine.

Anthrax immunization

The official site for the Anthrax Vaccine Immunization Program run by the U.S. Department of Defense. Register to subscribe to their free weekly updates. The site provides complete information about anthrax, its cure and prevention.

Bioterrorism preparedness and response

US emergency contacts and other resources, such as information on bioterrorism agents and illness recognition, from the Centers for Disease Control and Prevention (CDC).

Universal peace campaigns

Read about and choose to participate in one of the campaigns for world peace, organized by the Hague Appeal for Peace. Includes a calendar of public events (access it by first selecting “get involved” from their home page shown below).

Bioterrorism: Becoming an Informed Citizen

Students will work in groups of 6-7 to investigate six of the most common biological weapons and create a new section to the student’s textbooks on them.

Preparing for Bioterror

This lesson plan focuses on how America is preparing to respond to a potential bioterrorist attack.


Understanding Science