Importance of the Study
Biological surveillance of bioterrorism incidents has gained recent attention in public health and medical research. The bioterrorism incident of October 2001 showed the vulnerability of the U.S. population to biological agents, as well as the high cost of potential attacks. The likelihood of future attacks has not diminished. According to the National Intelligence Council, current trends indicate that the risk of an attack against the United States will increase in the coming years (Frist, 2002). Recent scientific and technological advances that allow weaponization of spores like anthrax also increase the threat. Although a likely scenario is a smaller attack that can sicken thousands and kill hundreds, the U.S. population will not tolerate such "malpractice error of omission" on the part of policy makers and public health authorities (Henretig, 2001). Congress has passed new legislation intended to strengthen the nation's biological surveillance by increasing funding of federal and state biological surveillance, even though the probability and potential size of bioterrorism incidents is unknown (Frist, 2002). Government funding for civilian biodefense increased dramatically from $414 million in 2001 to over $5 billion in 2004 (Schuler, 2004). President Bush's Fiscal Year 2005 budget request includes $407 million for the Bio-Surveillance Program Initiative to strengthen the public health infrastructure (Schuler, 2004). A key component of this initiative will be the expansion and deployment of the next generation of technologies related to the BioWatch Program, a biological-surveillance warning system. Presently, biological surveillance is used exclusively for bioterrorism detection.
BioWatch deploys biological sensors intended to detect potential releases of biological pathogens. It provides continuous monitoring of most major metropolitan areas and is designed to protect the nation against bioterrorism and strengthen the public health infrastructure. BioWatch also entails significant operation and maintenance costs, however. It is important that communities not spend more on biological surveillance than they reap in potential benefits from such a system, and public funding should maximize terrorism response capabilities (Fabian, 2002). Society's willingness to pay for prevention of future terrorism incidents should be based on the combined economic and public health damage that such attack can inflict. Therefore, before committing scarce resources to biosafety-enhancing technologies, policy makers should weigh the costs and benefits of biological surveillance.
Biological Surveillance: What Does It Buy?
A bioterrorist incident is considered a low-probability but high-cost event. The odds of such an event look even smaller from a local perspective (Berg, 2004). The costs are high, because biological agents are undetected until the onset of pathology, when treatment is less effective and more expensive, and fatalities are more probable. The human and economic impact of the bioterrorist attack depends on several factors:
* the agent or toxin used,
* the probability of infection,
* the number of people exposed,
* the speed of detection,
* the availability of treatment, and
* the potential for secondary transmission (if a contagious agent like smallpox is involved).
Agents can be detected either directly, with biological detectors like the ones used by BioWatch, or by collecting reports of their effect on a population from health care providers. The deployment of BioWatch allows detection of threatening biological pathogens such as anthrax in a manner timely enough to allow for effective prophylactic treatment. Even though vaccines exist for anthrax, as well as many other biological agents determined to pose a high risk by the Centers for Disease Control and Prevention (CDC), it is unlikely that vaccination of the entire population for a rare disease would be cost-effective. Early detection will allow the exposed population to be treated within a few days of an attack, thus greatly reducing the likelihood that people will develop symptoms, the probability that fatalities will occur, and the probability that a contagious virus will be transmitted. The biological detectors deployed under BioWatch include air-sampling hardware, sample collectors, and lab-testing facilities that can pinpoint within 16 to 36 hours the time and the place of an aerosol release of selected biological agents. The system of detectors cannot prevent the exposure. It can, however, provide early identification of the agent used and of the population exposed, before the onset of symptoms. According to the Department of Homeland Security (DHS) Web site, several dozen BioWatch sites are dispersed around the United States in major metropolitan areas. Understanding and quantifying the benefits of biological surveillance are essential to developing new biological-surveillance technologies and allocating public funds to such programs.
Contribution to the Previous Literature
Previous literature offers ambiguous evidence as to the benefits of biological surveillance. Although some studies find that the huge human and economic costs that could arise from...