Clinical Implications. Fast, accurate diagnosis limits the spread of exceptionally contagious diseases. Providing accurate information to patients minimizes misinformation and the associated public fear and panic that, unchecked, could overwhelm health care systems.

Vast amounts of information about potential biological agents, signs and symptoms, modes of treatment and appropriate responses to an attack have been amassed and made available on the World Wide Web and in journals. Distilling all of it into information that is usable in the dental environment and that can be accessed easily during an emergency or when treating a patient with suspicious symptoms is a challenge. The Web can be a maze with seemingly infinite numbers of tangential links with varying detail, emphasis and scientific basis. Many Web sites are directed toward the general public and fail to provide the depth of information useful to dental practitioners. Other sites are directed toward hospitals and laboratories with diagnostic capabilities that exceed those available to a typical dentist. Journal articles vary in quality and may become outdated.

In this article, we provide an easy-to-use guide for dental practitioners to use to assess quality information about bioterrorism and catastrophe response quickly. We limited the Web sites we cited to those sponsored by a federal institution or those of an academic or professional nature; we omitted commercially oriented Web sites. We identified journal citations by conducting a traditional literature review, and then we screened our results so that citations in the guide include articles published in English within the last six years in journals generally available at libraries in higher education institutions. Whenever possible, we included The Journal of the American Medical Association consensus statement articles. These articles, developed by the AMA’s Working Group on Civilian Biodefense, provide consensus-based recommendations for measures to be taken by medical and public health professionals if the agent being discussed is used as a biological weapon against a civilian population.

The Centers for Disease Control and Prevention’s Category A high-priority agents and diseases are the most likely to be used as weapons, posing a substantial risk to national security.

	BACKGROUND

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While any attack is frightening, attacks with biological agents are among the most insidious and breed the greatest fear. Attacks could go undetected for a long time, potentially exposing a vast number of people who are unaware of the threat. Because the initial response to many biological agents is nonspecific, flulike symptoms, diagnosis time often is delayed beyond the limit during which prophylactic measures, therapeutic measures or both are effective.

The Centers for Disease Control and Prevention, or CDC, ranks the biological agents and diseases that have the potential to be used as weapons into three categories.^1,2 Category A, high-priority agents and diseases, are the most likely to be used as weapons, posing a substantial risk to national security. Their classification reflects the ease of dissemination of the agent or transmission of the resulting disease, probable high mortality rates, the potential for major public health impact, the likelihood of causing public panic and social disruption, and challenges for public health preparedness. Category A agents and diseases include anthrax (Bacillus anthracis), botulism (Clostridium botulinum toxin), plague (Yersinia pestis), smallpox (variola major), tularemia (Francisella tularensis) and viral hemorrhagic fevers (Ebola, Lassa, Machupo and Marburg).

Category B biological agents and diseases are considered to be less easy to disseminate, have lower morbidity and mortality rates, and are less likely to challenge the public health system. Agents and diseases in this category include brucellosis (Brucella species), food safety threats (for example, Salmonella species), glanders (Burkholderia mallei), psittacosis (Chlamydia psittaci), Q fever (Coxiella burnetii), typhus fever (Rickettsia prowazekii) and water threats (for example, Vibrio cholerae).

Emerging pathogens are defined as Category C agents. They could be bioengineered for mass dissemination in the future because of their availability, ease of production and dissemination, and potential for high morbidity and mortality rates. Currently, Nipah virus and han-taviruses are Category C agents or diseases.

A wealth of information about bioterrorism and the use of biological agents as weapons throughout history can be found from Web sites sponsored by the U.S. Army,³ the CDC,⁴ the Infectious Diseases Society of America,⁵ the Infectious Disease Association of California⁶ and the Mayo Clinic.⁷ Journal articles of particular use include those by Miller,⁸ Lutwick and colleagues,⁹ Leggiadro,¹⁰ Kortepeter and Parker,¹¹ Varkey and colleagues,¹² Davis¹³ and Morens.¹⁴

	ORGANIZATION OF THE GUIDE

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Because biological attacks are more difficult to detect and have a greater potential to affect large segments of the population negatively than do chemical, radiological or explosive events, we decided to limit the focus of this article to biological agents only. We further narrowed the focus of this article to Category A diseases and agents, as they are the most likely threats.

The table lists Web sites and journal articles that can serve as resources for dentists about specific agents or diseases.^14–57 We suggest that health care workers be familiar with these resources and periodically revisit them, since familiarity with them, their content and their organization is essential for rapid review and use. In addition, information on the Web sites often is updated and a periodic review will allow health care workers to maintain an accurate listing of any changes.

We have provided three categories of resources for each agent. This organization reflects the diversity of roles that dentists and other health care professionals play in response to bioterrorist attacks and catastrophe response. Sources include summary fact sheets suitable for dentists to use for patient or community education (Column 2), background articles that give an overview of the disease and the history of the agent’s use as a weapon (Column 2), describe signs and symptoms (often accompanied by illustrations) (Column 3) and delineate current prophylactic and treatment approaches (Column 4).

Dentists can provide a valuable service to their patients and communities by providing quality information about the potential for attacks, what to watch for and how to respond appropriately should an attack occur.

We selected the table format for two reasons. First, responsible health care workers must acquire a minimum knowledge base to act responsibly in this post–Sept. 11, 2001, environment. Because Category A diseases are rare, most health care workers are unlikely to see the clinical signs and symptoms on a routine basis, and information that is not used routinely often is forgotten. Second, presenting resources in this format creates a guide that can be used easily under stressful conditions should an attack occur or be suspected.

Dentists can serve as effective communicators to their patients and the public. For example, the anthrax events in the fall of 2001 resulted in thousands of false alarms raised by people who were fearful of exposure and demanded that samples be tested. That demand exceeded the capacity of diagnostic laboratories, though anthrax was diagnosed in only 22 people.⁵⁸ By providing accurate and responsible information, the "white noise" of background misinformation and the ensuing public panic probably could have been minimized.

Dentists can provide a valuable service to their patients and communities by providing quality information about the potential for attacks, what to watch for and how to respond appropriately should an attack occur. The Web sites and journal articles we list in Column 2 (Fact Sheets/Background) of the table provide information that could be distributed to patients or public as a community service. However, none of these materials can be printed or reproduced without prior written permission of the copyright holder.

Another important role for dentists and other health care providers is to recognize the signs and symptoms of a biological attack early. This often is difficult, yet it is critically important. Initial signs and symptoms usually are nonspecific, flu-like general discomfort. Biowarfare agents can be disseminated massively, are self-propagating (and thereby quickly expand from local to national to international involvement), create extreme demands on the medical and public health system and simultaneously disrupt the medical and public health infrastructure by indiscriminately infecting care-givers and public health officials. Early recognition of atypical illness patterns and diagnostic clues could save millions of lives. Dark Winter, a simulation of a smallpox attack in the United States, pointed out the urgency of early response.⁵⁹ In this fictional scenario, 24 patients report to a hospital in Oklahoma on Sept. 12 with smallpoxlike symptoms. The vaccine, when available, is effective only before symptoms manifest, so it was anticipated that mortality would have been approximately 33 percent of the cases in which smallpox was diagnosed. Three thousand cases likely would have developed by Dec. 17. By Feb. 6, the number of cases could have risen to 3 million (with approximately 1 million deaths).

Meltzer and colleagues⁴⁰ modeled the spread of smallpox infection both with and without interventions such as vaccinations and quarantine. Without intervention, only 10 people who were infected initially would each infect three others, resulting in 64 people being infected within the first month, 4,500 by three months, 2.2 million by nine months, and 774 billion by the end of one year. O’Toole and Inglesby³³ modeled the spread of the plague, suggesting that four days after the first case is identified, 3,000 people could be dead and 15,000 could be ill with plaguelike symptoms. Clearly, even a few days saved by recognizing signs and symptoms could save a substantial number of lives. Column 3 (Signs and Symptoms) of the table provides resources that describe signs and symptoms, discuss differential diagnoses, and, for some agents, include photographs of typical disease expression.

Understanding prophylactic and vaccine status and treatment approaches also is of paramount importance to preparing for and responding to a bioterrorist attack intelligently. Column 4 (Prophylactic Measures and Treatment) of the table summarizes these resources. Because there is a lot of research and focus in this area, one advantage in using the Web is that the information posted will be the latest available in this constantly changing, dynamic environment.

	REPORTING STRANGE EVENTS OR OBSERVATIONS

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Our surprise at and response to the Sept. 11, 2001, attacks and the subsequent, intentional distribution of anthrax spores emphasized the need for information about appropriate responses to terrorist attacks. Noticeable increases in unusual illnesses, symptom complexes or disease patterns (even without definitive diagnosis) should be reported to public health authorities (go to "www.statepublichealth.org" to search for local and state public health departments’ contact information).

If local health officials suspect that illness is caused by a bioterrorist incident, they inform and involve the state health department that, in turn, notifies the CDC following a flow chart with explanations for responsibilities at each step.⁶⁰ The CDC then conducts an investigation to confirm whether a bioterrorist attack has occurred. If so, it notifies the FBI, which proceeds with its own investigation.

When local health officials become aware that a bioterrorist event has occurred or that a threat has been made, they first notify the FBI and local law enforcement officers. Then they notify and involve the state health department and other response partners according to a pre-established notification list, which, ultimately, includes the CDC. Discussion of behind-the-scenes responses and epidemiologic investigations can be found in Butler and colleagues⁶¹ and Bales and colleagues.⁶² The CDC^58,63 emphasizes the urgency of rapid recognition of clinical signs and symptoms and the appropriate use of masks and isolation, especially with patients with infectious diseases.

The United States Postal Service has been used to deliver biological agents as weapons. Information about general precautions and proper response protocol for handling letters or packages suspected to include biological agents is available at "www.nysegov.com/news/anthraxinfo.htm" and "www.usps.com/news/2001/press/pr01_1010tips.htm" or by calling your local post office. Letters or packages that are suspected to be biological agents should be handled as little as possible and be isolated. Local law enforcement authorities should be called immediately. As soon as is practical, everyone known to have touched the letters or packages should take a shower using soap and water. A list of these people and their contact information should be prepared for the authorities for subsequent investigations and so that intelligent treatment decisions can be made if needed. For questions that cannot be answered otherwise, the CDC has a 24-hour emergency response hotline at 1-770-488-7100.

	CONCLUSIONS

TOP BACKGROUND ORGANIZATION OF THE GUIDE REPORTING STRANGE EVENTS OR... CONCLUSIONS

 
The threat of terrorist attacks has redefined the role that dentists can play in response to a catastrophe. Armed with information about biological agents that could be used as weapons, dentists can provide accurate information to their patients and communities, recognize signs and symptoms of responses to biological agents—which can facilitate diagnosis and help contain further spread of the diseases and agents—and direct patients to seek appropriate prophylactic measures or treatment.

The reference guide we created focuses on the agents most likely to be used in biological attacks. It is intended to facilitate ready access to relevant resources. Web-based resources likely will remain the timeliest because they are updated continually to incorporate the newest advances. Journal articles can be used to create a private library of resources that could be used should the Web become unavailable in an attack.

The guide also provides a platform for dentists to use to prepare contingency plans for their own responses to an attack and to consider when defining their broader role in future health care delivery, including being involved in emergency teams; providing triage and shock management; acquiring further education in this field; or converting their practices into minihospitals to meet surges in demand for medical care.