The Generation 3 BioWatch system has not yet been selected, so its assessment can be based only on the proposed operational requirements (DHS, 2008, 2009).
The public health and health care systems regularly face the need to recognize and respond to naturally occurring disease outbreaks and seasonal illness and are also expected to be able to detect and respond to bioterrorism events. Assessments of the effectiveness of surveillance systems in detecting disease outbreaks are limited, especially for newer syndromic surveillance techniques (Bravata et al., 2004; CDC, 2004; Buckeridge, 2007). In trying to determine their effectiveness in the event of bioterrorism, it is necessary to rely on simulations because actual data are not available.
Biosurveillance within the public health system is composed of numerous separate systems, varying in maturity, whose integrated cost and performance is difficult to assess for detection of either natural disease outbreaks or bioterrorist events, whether alone or in conjunction with BioWatch.
Natural outbreaks are heterogeneous, differing in size, location, agent, and mechanism of spread, as are the capabilities of state and local public health departments to recognize and respond to outbreaks and the availability of health care resources to provide treatment. Assessing the effectiveness of a potentially enhanced surveillance system is even more challenging.
The digitalization of health information that could improve the speed and ease of disease surveillance remains incomplete.
Despite these challenges, it is possible to make a basic but informative comparison of BioWatch with surveillance through the public health and health care systems.
A fundamental question is whether BioWatch can perform in a useful way. Answering this question requires considering several interrelated events that are necessary for BioWatch to contribute to the reduction of illness and loss of life (see Table 6-1). The official estimates of the probabilities of some of these events, especially that a bioterrorism attack will occur, that it will take place in a BioWatch jurisdiction, and that it will be delivered in a manner that BioWatch has the potential to detect, have not been made available to the committee. With the understanding that judgments about these probabilities will be crucial to policy decisions that must be made about the refinement and further deployment of BioWatch, the committee looked at the system’s potential performance assuming there is a detectable attack, that is, a large-scale airborne release of one of the