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3 Evaluation of the BioWatch System
Pages 61-95

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From page 61...
... In its evaluation, the committee considered the entire BioWatch "system," as introduced in Chapter 1 -- the technology to collect and test air samples, the associated laboratory assays, the additional information gathering needed to confirm and characterize an incident, operational guidance, interagency and risk communication, response planning, and the personnel to support these operations. It also looked at the BioWatch program -- the programmatic activity managed and funded by the Office of Health Affairs (OHA)
From page 62...
... As noted in Chapter 1, evaluation of the likelihood of an airborne biological attack that could be detected by the BioWatch system is beyond the committee's scope, as is an evaluation of the ability of public health officials to deliver mass prophylaxis in a limited time period. Here, the committee evaluates elements of the BioWatch system that are necessary, if not sufficient, for the system to be effective, including the air samplers and their placement, the samplers' capture of targeted organisms, the laboratory assays, information reporting, event characterization, and public health decision making.
From page 63...
... DHS does not consider these BARs to be "false positives" because the target DNA was actually detected by the specified assays.1 The committee's view is that from an operational perspective these detections can indeed be considered "BAR false positives," because the detections were not the result of a bioterrorist attack. The laboratory assays used to detect the presence of genetic material from biological agents of interest need to be both specific and sensitive: that is, the assay must have a high probability of detecting the biological agents that BioWatch targets and have a low probability of reporting the presence of genetic material from other organisms as "detections." Several agents of concern, and their close genetic relatives, exist naturally in water or soil (Kuske, 2005; Kuske et al., 2006)
From page 64...
... To the extent that the analysis of BioWatch samples can relate the amount of genetic material present in a sample to infectious dose, the information is likely to aid public health officials in planning a response. But BioWatch collectors and assays should be sensitive enough to detect small quantities of genetic material for a targeted pathogen, because the presence of small quantities at one collector may be related to the presence of much larger quantities elsewhere or, perhaps, a failed attack that requires further investigation.
From page 65...
... PUBLIC HEALTH RESPONSE TO A BAR DHS has direct programmatic responsibility for the BioWatch air samplers, laboratory assays, and the reporting of assay results by its contractor staff to local public health officials. DHS's role after the declaration of a BAR, along with that of HHS/CDC and other federal partners, is to support 2 Simulants to be used in such tests would be nonpathogenic or nontoxic surrogates for bioterrorism agents.
From page 66...
... . Public health officials also told the committee that DHS had initially been reluctant to inform local and state officials about the locations of BioWatch air samplers within their own jurisdictions.
From page 67...
... The BioWatch system relies on prompt public health action, such as prophylaxis in response to a BAR, to be most effective in saving lives. Critical to the success of the BioWatch system is the confidence of local and state public health officials and decision makers in the system's detection and assay technology, and in their ability to work as partners with DHS and other federal agencies in preparing for and possibly having to respond to a bioterrorist attack detected through BioWatch.
From page 68...
... (2) If so, or if an attack cannot be ruled out, should public health officials begin to mobilize to start prophylaxis, and what population should be targeted initially?
From page 69...
... For example, the Bioagent Event Reconstruction Tool (BERT) employs modeling to simulate what might happen during an airborne biological agent attack (Brown et al., 2006)
From page 70...
... developing New and Better Tools to Aid decision makers The committee urges action to improve tools for environmental characterization of the nature and extent of aerosol releases of biological agents in order to inform public health decision makers following a BAR. DHS should work with HHS (CDC)
From page 71...
...  EVAluATION OF THE BIOWATCH SySTEm BOX 3-1 Potential Approaches for Improving Incident Characterization If release of a bioterrorism agent is suspected or confirmed, public health officials will need additional information to understand the scale of the release and the extent of the dispersion of the agent. Various ap proaches to producing such information could be developed and tested to determine their feasibility and effectiveness.
From page 72...
... Because experience with BARs is currently limited to the detection of certain naturally occurring organisms, it will be important to understand whether or how this experience can be applied to the decision making that would follow a BAR for other biological agents. Assistance to Jurisdictions in Responding to a BAR With the declaration of a BAR, the planned procedure is for local public health officials to immediately notify both DHS and CDC, and for CDC to "provide public health consultation, support, and guidance to BioWatch jurisdictions regarding disease surveillance, laboratory issues, and/or environmental and occupational health" (DHS, 2008c, p.
From page 73...
... This resource should be integrated with the local incident command. Learning from BioWatch Exercises and BARs Since the initial deployment of BioWatch in 2003, numerous exercises have been held by BioWatch jurisdictions to plan and prepare for a bioterrorist attack that might be detected by the BioWatch system.
From page 74...
... Updates on lessons learned should be a standing agenda topic for an external BioWatch advisory panel (see Recom 6 The Homeland Security Exercise and Evaluation Program provides a standardized methodology and terminology for the design, development, conduct, evaluation, and improvement of preparedness and response exercises. The Target Capabilities List offers a guide to capabilities considered necessary to prevent, protect against, respond to, and recover from major events of all types.
From page 75...
... Lessons learned should also inform capacity-building and technical assistance programs for state and local public health departments participating in BioWatch. Support for BioWatch Operations The introduction of the BioWatch system into major metropolitan areas across the country has generated a variety of additional responsibili
From page 76...
... through additional and improved training, exercises, and information exchange; • developing, validating, and implementing rapid environmental sampling and testing methodologies to characterize the scale and scope of the incident immediately post-BAR. As validated methodologies are developed, situational awareness and decision support systems with analytical tools to facilitate analysis of critical information needed to inform decisions in response to a BAR should be developed; • preparing detailed guidance for local and state public health officials with specific recommendations on public health measures and decisions following a BAR; • ensuring that a team, with specific training in reacting to BARs and relevant subject matter expertise (e.g., infectious disease epidemiol ogy, laboratory science, environmental assessment, risk communication)
From page 77...
... In principle, faster and more frequent testing provides the opportunity for earlier detection of a biological agent and therefore an earlier decision to begin a public health response, which may result in a significant increase in lives saved over a Generation 2 time line.
From page 78...
... Currently, a few hundred air samplers are deployed (DHS, 2008a)
From page 79...
... . Operational requirements have been set for the automated sample collection, preparation, analysis, preservation of samples, and waste handling.
From page 80...
... The committee saw no indication that DHS is planning to assess the environmental background levels of monitored pathogens in the BioWatch jurisdictions. This information could reveal whether environmental backgrounds will affect the performance of the biodetector assays.
From page 81...
... This reinforces the need for validation of the assay component of the system. Moreover, the committee emphasizes that selection of biological agents for Generation 3 should be based on risk analyses and riskmanagement considerations to avoid inclusion of pathogens for which BioWatch is not an appropriate detection tool and unnecessary investment in related technology and assay development.
From page 82...
... To ensure that the goals of the test plan address public health needs, it is important that state and local public health officials be involved in the entire process. The absence of a formal means of involving these stakeholders gives the impression that DHS does not view their perspectives as a necessary and valuable component of the testing process.
From page 83...
... ; • the effectiveness of the BioWatch training program for its operators; • the ability of the BioWatch logistics system to provide adequate support to the operators and end users; and • the suitability of BioWatch data to support low- and high-regret response decisions by local public health officials for the full spectrum of agents and bounding scenarios. Operational test results should be evaluated against measures of effectiveness that are collaboratively developed by the BioWatch program office and the public health community.
From page 84...
... CHALLENGES TO DEVELOPMENT OF GENERATION 3 TECHNOLOGY If BioWatch Generation 3 technology can be successfully developed and deployed, it could facilitate greater population coverage, aid in achieving an earlier initiation of a public health response to an attack, and reduce per-unit operating costs by eliminating filter transport and manual analysis. However, it is not apparent that science and technology exist that can be engineered into a functional detector that meets, even marginally, the proposed performance requirements for Generation 3.
From page 85...
... For example, developments in engineering research may permit creation of more robust and inexpensive detector platforms, and new communication systems and network architectures will support "smart" networks. Opportunities also exist to refine the analysis of BioWatch air samples, but an important prerequisite is the characterization of endemic environmental organisms in and near BioWatch jurisdictions to establish background levels of both the pathogens of concern and near relatives that might cross-react in assays.
From page 86...
... OHA should ensure that operational needs and concerns from BioWatch jurisdictions and federal BioWatch partners are brought to the development effort, while S&T should ensure that Generation 3 development responds to both technological opportunities and hazards. RECOMMENDATION 4: DHS should improve the level of coopera tion and collaboration between its Office of Health Affairs and its Science and Technology Directorate to promote effective research and technology development in support of the BioWatch program.
From page 87...
... Through research on host–pathogen interactions it may prove possible to identify genetic or molecular markers that signal virulence or antimicrobial resistance in pathogens or increased vulnerability in human hosts. This kind of information may make it possible to devise more informative detection techniques that would help public health officials maximize the effectiveness of their response plans.
From page 88...
... . The BioWatch air samplers currently in use have capabilities that may be useful for such research.
From page 89...
... The BioWatch program management has apparently placed more emphasis on the "early detection" aspect of a bioaerosol monitoring capability than on "enabling timely response and mitigation." Facilitating response and mitigation requires cooperation among DHS, public health, and other federal partners and the integration and assessment of many different types of information. The concerns of local
From page 90...
... DHS might, for example, consider whether special event monitoring would be more effective than constant monitoring, or whether focusing on transportation hubs would be better than attempting comprehensive coverage of localities. Any plans to add biological agents to the set to be monitored by the BioWatch system should include an assessment of whether analytical challenges will be encountered because of natural background levels of these biological agent signatures or the presence of other interferents.
From page 91...
... Among the members should be state and local officials responsible for responding to a BAR. To further coordination and communication between DHS and HHS, the advisory panel should report jointly to both secretaries.
From page 92...
... 2006. An operational event reconstruction tool: Source inversion for biological agent detectors.
From page 93...
... 2008c. BioWatch outdoor program: guidance documents for BioWatch jurisdictions.
From page 94...
... 2005. Health officials vigilant for illness after sensors detect bacteria on Mall.
From page 95...
... 2008b. department of Homeland Security Bioterrorism Risk Assessment: A call for change.


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