The deaths, illnesses, and pervasive sense of fear caused by the exposure of Americans to a series of anthrax-tainted letters have demonstrated that bioterrorism poses a "clear and present danger" to U.S. national security. Although the scale of the attacks has so far been limited, the anthrax crisis has exposed serious gaps in the nation’s public health defenses, particularly at the state and local levels. Both Congress and the administration must address these problems if the country is to be prepared for more extensive attacks in the future.
In the event of a major incident of bioterrorism, city, county, and state health departments would be the nation’s first line of defense, backed up by the medical detectives at the Centers for Disease Control and Prevention (CDC) and other federal agencies. If terrorists disseminated anthrax spores through the air as an invisible, odorless aerosol cloud, the targeted individuals would probably be unaware that they had been infected. The first evidence would emerge a few days later with the appearance of nonspecific flulike symptoms such as fever, fatigue, cough, and chest discomfort. Without prompt medical treatment, severe symptoms would set in, including difficulty breathing, meningitis, and shock. Although anthrax is not transmissible from person to person, the pulmonary form of the disease is often fatal within 24 to 36 hours after the onset of acute symptoms. Because antibiotic therapy must begin as soon as possible to have a good chance of success, prompt detection and diagnosis of an outbreak would save many lives.
An even more challenging scenario would involve the deliberate release of a contagious agent, such as plague bacteria or smallpox virus. The incubation period of plague is 1 to 6 days, and that of smallpox is roughly 12 to 14 days. By the time the first cases of smallpox were diagnosed, the initial group of infected individuals would probably have transmitted the disease to others. In this case it would be essential to launch an aggressive vaccination campaign to contain the epidemic before it spread through the general population in a series of expanding waves.
Detecting and Containing an Outbreak
Detection and containment of a disease outbreak resulting from the deliberate release of a biological agent would entail three basic steps:
1. Recognition and diagnosis. Primary health care providers would identify one or more cases of an unusual infectious disease or an undiagnosed "syndrome" (cluster of symptoms). Clinical laboratories would attempt to identify the causative agent from patient specimens.
2. Communication of surveillance information. Clinicians who detected cases of unusual illness would report their observations to local or state public health authorities. Epidemiologists would integrate reports from multiple sites to assess the nature of the outbreak and whether it was attributable to unnatural causes.
3. Delivery of medical and public health measures. Drugs and medical supplies would be airlifted to the site of the outbreak within hours, accompanied by U.S. Public Health Service teams who would supervise distribution. Patients would be triaged, and the seriously ill admitted to hospitals for treatment. In the event of an attack with a contagious agent, the infected individuals would be quarantined. Assuming vaccine is available, all known or potential contacts would be traced and vaccinated to prevent the epidemic from spreading.
Today, a major outbreak of disease arising from an act of bioterrorism would pose serious challenges to the U.S. public health system with respect to rapid detection, diagnosis, and containment. In the past, public health authorities have had ample time to respond to slow-acting diseases such as tuberculosis or AIDS, but this rule does not apply to bioterrorist threats such as anthrax or plague. If thousands of people were infected through the lungs by a cloud of aerosolized anthrax spores, they would have to be treated within 36 hours to prevent fatalities, leaving little margin for error.
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"If thousands of people were infected through the lungs by a cloud of aerosolized anthrax spores, those people would have to be treated within 36 hours." |
Unfortunately, the U.S. public health system has been allowed to atrophy over the past several decades. In the 1950s and 1960s, publicly supported community hospitals and public health laboratories provided an early-warning network for detecting and containing epidemics. Since then, however, the privatization of hospitals, managed care, and complacency about the control of epidemic diseases have led to drastic cutbacks in the nation’s public health infrastructure. Although New York City’s Department of Health is one of the best in the country, it was stretched to the breaking point by the series of anthrax exposures that began to appear in early October 2001. The department’s clinical laboratory was inundated with between 80 to 100 suspected anthrax samples a day, most of which proved to be hoaxes or false alarms.
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"The privatization of hospitals, managed care, and complacency about the control of epidemic diseases have led to drastic cutbacks in the nation’s public health infrastructure." |
The rest of the country is even less prepared to deal with a major incident of bioterrorism. At least 140 counties in the United States do not even have a health department, and of those that do, many do not employ a single epidemiologist or have enough staff to provide coverage at night or on weekends. A recent study by the CDC found that less than half the nation’s 3,000 health departments have high-speed Internet access and that 10 percent have no e-mail. These deficiencies limit the sensitivity and responsiveness of disease surveillance across the country and would seriously impede the timely detection of a bioterrorist attack.
The U.S. hospital system is also unprepared to deal with a major incident of bioterrorism. Because of the economics of medical insurance and managed care, urban hospitals operate under severe financial constraints. Many facilities have slashed the number of beds and eliminated stockpiles of antibiotics and other drugs, purchasing them instead on a "just in time" basis. As a result, the medical system lacks the surge capacity that would be needed to treat the victims of a large-scale bioterrorist attack, particularly one involving a contagious agent.
Policy Recommendations
Although the federal government is moving to increase its reserve stockpiles of antibiotics and vaccines, far more needs to be done to strengthen the U.S. public health infrastructure through targeted block grants to the states. If health care providers are to be effective sentinels of a bioterrorist attack, they must have the training and professional awareness to do so. Clinicians also require direct channels of communication to city and county health departments, which must have adequate staff coverage so that doctors can report suspicious cases of disease whenever they are detected, 24 hours a day, seven days a week. In order to meet these vital requirements, the following steps are warranted:
1. Strengthen Disease Surveillance Systems around the Country. To prepare for a range of contingencies, clinicians should be trained to recognize the signs and symptoms of exotic diseases that they would normally not encounter in their medical practice, including anthrax, plague, smallpox, tularemia, and hemorrhagic fevers. Such training should be delivered through continuing medical education courses/web sites and could be made a requirement for medical licensing or board certification in specialties such as infectious disease and emergency medicine. Clinical laboratories across the country must be equipped with the necessary diagnostic tools to identify bioterrorist threat agents in patient specimens. Furthermore, national distribution systems for drugs and vaccines should be refined and rehearsed so that an epidemic of contagious disease could be contained rapidly. One approach would be to organize and train local teams of medical volunteers, who would be mobilized in an emergency to treat victims and vaccinate large numbers of people.
The nation’s disease monitoring systems must also be strengthened across the board. Since the September 11 attacks, the New York City Department of Health has heightened its vigilance against bioterrorism by expanding its disease surveillance network to cover 28 hospitals in all five boroughs, including physicians in emergency rooms, intensive care units, and dermatology clinics. City health officials send out alerts and updates by e-mail and fax, indicating the signs and symptoms of bioterrorist threat agents and providing references to web sites for photos of characteristic skin lesions. Every day, the participating hospitals and clinics submit data in electronic form to the health department on reportable infectious diseases and undiagnosed respiratory syndromes.
Because harried clinicians do not always comply fully with the disease-reporting requirements, the New York City Department of Health supplements this approach with a computer-based monitoring system known as "syndromic surveillance." The department collects information daily on a variety of public health indicators, including 911 ambulance calls, walk-in emergency room visits, pharmacy sales of cold and antidiarrhea medications, and illnesses among city transit workers. These data, tagged by medical condition and zip code, are transferred electronically to the health department, where a sophisticated computer program helps to spot anomalies that could be indicative of an unusual outbreak of infectious disease. Although this "data mining" system can generate false alarms, it has already managed to detect the onset of flu season two or three weeks earlier than reported by clinicians. New York City’s innovative approach of combining physician reporting with syndromic surveillance offers a useful model for other major cities to follow.
In addition to improving the sensitivity and responsiveness of disease surveillance systems across the country, the various elements of the U.S. public health system at the local, county, state, and federal levels must be integrated by e-mail and other means of communication into a seamless web. Although the CDC has establishedelectronic links, known as the Health Alert Network, with state and local health departments, this system is still incomplete and requires more useful content. In addition, the network should employ a secure, reliable system such as the File Transfer Protocol (FTP) to safeguard confidential patient records and minimize the risk that urgent messages will be bottlenecked in a crisis by high volumes of e-mail traffic.
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"At least 140 counties in the United States do not even have a health department, and of those that do, many do not employ a single epidemiologist or have enough staff to provide coverage at night or on weekends." |
2. Expand "Surge Capacity" in Health Departments and Diagnostic Labs. Both health departments and diagnostic labs require greater "surge capacity" to cope with an unexpected disaster. As a first step, disease surveillance capabilities must be bolstered at the state and local levels to provide sufficient staff for round-the-clock emergency operations. The CDC should also establish a ready reserve of bioterrorism experts who could be rapidly deployed to an affected city or state in the event of an attack. One approach would be to expand the Epidemic Intelligence Service (EIS), the federal corps of epidemiologists who investigate major disease outbreaks around the United States. Increasing the size of the EIS class from the current level of 70 to at least 100, and extending the program from two years to three, would make it possible to station an EIS officer in each state and to deploy additional epidemiologists as backup in an emergency.
3. Establish Systems for Triage in the Event of an Attack. Once an unusual outbreak of disease arising from a covert bioterrorist attack has been detected and diagnosed, the next phase would be to launch an emergency medical response. Given the lack of excess capacity in hospitals today, emergency rooms would be rapidly overwhelmed if large numbers of patients descended on them for treatment. During the 1995 sarin nerve gas attack on the Tokyo subway, for example, more than 85 percent of the people who arrived at hospitals were suffering from anxiety or psychosomatic symptoms, with no evidence of actual toxic exposure. For this reason, a system of mobile medical clinics should be established in each major U.S. city to conduct triage in the aftermath of a bioterrorist attack. The mobile clinics would screen out the "worried well" and refer only seriously ill individuals to hospital emergency rooms for treatment.
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"Urban hospitals lack the surge capacity that would be needed to treat the victims of a large-scale bioterrorist attack, particularly one involving a contagious agent." |
4. Improve the Intelligence Community’s Ability to Assess Bioterrorism Threats. Preventing a bioterrorist attack is clearly preferable to managing the consequences, but prevention poses major technical challenges. The ability of the U.S. intelligence community to assess the acquisition and production of biological agents by terrorists is currently limited by the lack of field operatives and analysts with expertise in microbiology, epidemiology, and infectious diseases.
To remedy this situation, the Central Intelligence Agency, the Defense Intelligence Agency (DIA), and the Federal Bureau of Investigation should recruit more individuals with advanced scientific and medical training to assess biowarfare and bioterrorism threats. In particular, the DIA’s Armed Forces Medical Intelligence Center, the one intelligence organization specializing in infectious diseases, should have 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.
Complementing this effort, the U.S. Public Health Service (PHS) should establish an elite cadre of epidemiologists with security clearances and access to secure communications, such as encrypted phone and fax lines and videoconferencing facilities. These individuals would remain on call to provide technical advice to intelligence analysts seeking to interpret raw data on terrorist capabilities or to determine whether a suspicious disease outbreak could be the result of covert biological attack. The PHS experts would perform a role similar to the advisers to the Department of Energy’s Nuclear Emergency Search Team who help to assess the credibility of threats of nuclear terrorism.
Conclusions
Bioterrorism, until recently a largely hypothetical threat, has now become a harsh reality. Although the anthrax attacks through the mail have fortunately remained limited, a larger-scale incident involving the deliberate release of aerosolized anthrax or some other pathogen could result in serious loss of life and social disruption. Congress and the administration have a window of opportunity to strengthen the nation’s public health defenses by providing targeted block grants to state health departments. Unless the current gaps are corrected, they could impede the early detection of a bioterrorist attack and the prompt medical response needed to minimize casualties.
In upgrading the U.S. public health infrastructure, the federal government should pursue a coherent plan of action and a clear set of priorities. Bioterrorism is an emerging threat that must be addressed in a systematic and sustained way, avoiding the cycle of alarmism and complacency that has hampered earlier efforts. At the same time, strengthening the nation’s long-neglected public health system will pay substantial dividends by shielding Americans against natural outbreaks of infectious disease, whether or not a large-scale bioterrorist attack ever materializes.
