The BioWatch Program: Detection of Bioterrorism
Released: 2003-11-19T00:00:00

Introduction

During the 2003 State of the Union address, President Bush announced that the federalgovernment was "deploying the nation's first early warning network of sensors to detect biologicalattack." (1) The newlyformed Department of Homeland Security (DHS), is responsible for deploying this network, theBioWatch Program, reportedly as part of the Biological Warning and Incident CharacterizationSystem. (2) Funded andoverseen by DHS, the program has three main elements each coordinated by different agencies,sampling, analysis, and response. The Environmental Protection Agency (EPA) maintains thesampling component, the sensors that collect airborne particles. The Centers for Disease Controland Prevention (CDC) coordinates analysis, the laboratory testing of the samples, though testing isactually carried out in state and local public health laboratories. Local jurisdictions are responsiblefor the public health response to positive findings. The Federal Bureau of Investigation (FBI) isdesignated as the lead agency for the law enforcement response if a bioterrorism event is detected.The installation of the sensor network is ongoing, with over 30 cities chosen as locations for thesesensors. (3)

The detection of a covert act of bioterrorism, unless detected by the BioWatch Program, islikely to occur through the diagnosis of ill victims. Detection is delayed from the time of the actualevent by the time required to develop symptoms and report them. For many pathogens, earlytreatment, preferably before symptoms develop, is key to preventing casualties. If early detectionis achieved, it is predicted that therapeutic agents could be provided in a timely manner to thoseexposed, reducing the effectiveness of such an attack and averting the potentially catastrophic natureof mass pathogen releases. While pathogen detection systems are employed by the military, suchsystems were not previously deployed on such a scale in the civilian sector.

A fundamental question to be asked of the BioWatch Program is whether it is an appropriatefederal response to the threat of bioterrorism. The historic cases of bioterrorism within the UnitedStates have been small in scope, and likely would not be detected by the current system. Additionally, the Central Intelligence Agency has reported that while al-Qaeda maintains the goalof mass casualties, most attacks will be small scale. (4) The deployment of a bioterrorism detection system with a primarygoal of detecting large releases of pathogen may not be viewed as the optimum response to thecurrent threat.

The BioWatch Program garners public and Congressional interest for a variety of reasons,including its cost, the future development and testing of similar systems, the effectiveness of thecurrently deployed system, the process by which this program was chosen and deployed, and theconsequence-management process envisioned in response to a BioWatch warning. These issues mayraise questions about the role that the Department of Homeland Security plays with respect to thepublic health infrastructure, aspects of federal and state communication and coordination, and therole of the federal and state governments in protecting the populace against biological attack.

What is the BioWatch Program?

The function of the BioWatch Program is to detect the release of pathogens into the air,providing warning to the government and public health community of a potential bioterror event. While there is limited federal government description of the BioWatch Program, there have beenmedia reports describing the functional concept. (5) According to these reports, aerosol samplers mounted onpreexisting EPA air quality monitoring stations collect air, passing it through filters. These filtersare manually collected at regular, reportedly 24-hour, intervals (6) and are analyzed for potentialbiological weapon pathogens using polymerase chain reaction (PCR) techniques. (7) While filters from theBioWatch program were initially shipped to and tested at a federal laboratory in California, state andlocal public health laboratories now perform the analyses. (8) News reports suggest that the system tests for the pathogens thatcause anthrax, smallpox, plague, and tularemia (a bacterial illness, sometimes called "rabbit fever"),but the entire list of pathogens is not publicly available. (9)

The BioWatch equipment is fielded in select cities, reportedly including Philadelphia, NewYork City, Washington, DC, San Diego, Boston, Chicago, San Francisco, St. Louis, Houston, andLos Angeles. (10) TheDepartment of Homeland Security has not confirmed the exact number of cities engaged in theBioWatch program, nor the number of pathogens that are detected using BioWatch equipment. (11) It is reported that at least31 cities are included in the BioWatch program, while according to the minutes of a Centers forDisease Control and Prevention (CDC) Information Council meeting, the program may expand toas many as 120 cities. (12) While the exact cost of this program is unknown, the capital costs for installation in a single city areestimated at $1 million and the yearly budget for operation at $1 million per city. (13)

The press has reported that the state and local public health labs conducting BioWatch testingare all part of the national Laboratory Response Network for Bioterrorism (LRN). (14) The LRN is a nationwidenetwork composed primarily of local, state, and federal government laboratories that provideconfirmatory testing of potential bioterrorism pathogens, using consensus protocols. It wasdeveloped by Centers for Disease Control and Prevention (CDC), the Federal Bureau ofInvestigation, and the Association of Public Health Laboratories prior to the anthrax mailings of2001. It provides confirmatory testing in all 50 state public health labs, and in additionallocations. (15) There arecurrently 118 member labs in the LRN.

BioWatch equipment is heavily based on the Biological Aerosol Sentry and InformationSystem (BASIS), a system developed within the Chemical and Biological National Security Programof the National Nuclear Security Administration (now part of the Department of Homeland Security)by scientists at Lawrence Livermore and Los Alamos National Laboratories. (16) BASIS is comprised ofan air collector coupled to a series of filters. Airborne particles passing through the system arecaptured on a filter. The filter mechanism is designed to roughly determine when an attack occurredby using sequential filters automatically rotated on an hourly basis. Filters are removed and testedusing PCR for the presence of select pathogens.

BASIS was deployed for both indoor and outdoor monitoring at the Salt Lake City Olympicsin 2002, and was also tested and characterized in urban settings. (17) Some conclusions aboutinstrument performance based on these tests were released. BASIS was characterized as having highspecificity, with fewer than 0.005% false positives per filter measurement, (18) and high sensitivity. (19) However, BASIS wasnoted to be labor intensive, requiring people to collect filters and perform PCR testing and analysis.

The first incident of a positive BioWatch result was reported on October 9, 2003 in Houston,Texas. The Houston Department of Health and Human Services reported detecting low levels of thebacterium that causes tularemia. According to a press release, positive results were detected on threeconsecutive days, with negative results on subsequent days. (20) The response to thepositive result was a modest one with precautionary measures being taken by the local and statepublic health agencies, including increased surveillance for human illness; additional environmentalsampling and testing; and assessment of activities in the area that may have caused the sensors topick up the organism. There are no indications that this signal was the result of an intentionalpathogen release, but investigation is ongoing with federal, state and local agency participation. (21) The Director of theHouston Department of Health and Human Services stated, "We are investigating to determine if thebacteria was always present or newly present and if it represents a health threat to the community." These findings may likely reflect natural "background" levels of the organism in the environment,and authorities have chosen to enhance surveillance rather than distributing antibiotics in the affectedcommunity. (22)

Reactions to the BioWatch Program

The BioWatch program has received a mixed reaction from experts. While acknowledgingthe program may address a noted homeland security vulnerability, commentators and analysts haveraised concerns in a number of areas. This section presents some of these concerns, including overallstrategy, sensor siting, detector performance, and public health response.

Strategic Issues

Countering the threat of terrorist use of weapons of mass destruction against civilians hastaken on new priority since the anthrax mailings of 2001. President Bush, when announcing thedeployment of the BioWatch program during the 2003 State of the Union Address, stated,

Today, the gravest danger in the war on terror, thegravest danger facing America and the world, is outlaw regimes that seek and possess nuclear,chemical, and biological weapons. These regimes could use such weapons for blackmail, terror, andmass murder. They could also give or sell those weapons to terrorist allies, who would use themwithout the least hesitation. (23)

A goal of the BioWatch program is detection of large releases of biological weapons, someof which might potentially cause thousands of casualties. (24) Early notification of a biological attack is presumed to providea significant advantage in preventing and treating casualties. Such a "detect to treat" (25) warning system may limitcasualties and fatalities by allowing earlier medical service to the exposed, avoiding diseaseprogression. A modeling study concludes that while the earliest possible detection of a hypotheticalurban anthrax release still cannot prevent all deaths, the proportion of lives saved by detection andintervention within the first day after the event (before symptoms appear in those exposed) isapproximately 40%. (26) With increasing delay between detection and treatment, greater casualties occur.

Some experts question whether mass biological attack is the most probable terrorist threat,and suggest that more localized attacks are more likely. (27) It is suggested by some that the BioWatch monitors would notlikely detect indoor or underground releases, such as within a building or a subway system. (28) There are historicalexamples of both indoor releases, the U.S. anthrax mailings in 2001, and outdoor releases, such asthe suspected accidental anthrax release at Sverdlovsk (now Ekaterinburg), Russia in 1979. (29)

Factors influencing the choice of locales to be monitored are another area of discussion. BioWatch monitors are reportedly deployed in major cities. A successful mass biological attack ona large city would likely cause high casualties. The perceived prestige conferred upon a terroristgroup following a successful, large-scale attack may lead terrorist groups to preferentially targetcities. (30) Some positthat these factors, among others, require special consideration for major cities. For example, in thedebate over homeland security spending, some have asserted that homeland security funds shouldbe allocated using formulas that take into account threats, population density, and the presence ofcritical infrastructure, rather than on a per capita basis. (31) In contrast, some have claimed that successful aerosoldissemination near a major city is less likely due to the higher probability that such an event wouldbe noticed by officials or citizens. (32)

Some feel that the existence of bioterrorism countermeasures can themselves serve as adeterrent to the use of these agents. In theory, the BioWatch program might have this effect, withpotential bioterrorists knowing that cities have early warning capability due to the BioWatchprogram being deterred from using biological weapons. Some may conclude that this deterrent valueis enhanced by the general secrecy surrounding BioWatch program details, such as monitor locationsand pathogen lists. The deterrence value may be difficult to measure, and may alternately directterrorists toward locations lacking such detectors. Also, the general secrecy surrounding theBioWatch program details may lead potential bioterrorists to underestimate the system's truecapability, decreasing the deterrent effect.

Sensor Siting Issues

Technical issues regarding placement of BioWatch monitors are raised as potentiallimitations to the system's effectiveness. Some BioWatch monitors are reportedly co-located withpreexisting EPA air quality monitors, (33) though potentially the monitors could be relocated should theneed arise. (34) Regulations regarding placement of EPA air quality monitors are found at 40 CFR 58, and, amongother criteria, placement is designed to assess the impact of potential pollutant sources for a givenarea. Since these criteria are different from those designed for biological detection, the placementof the EPA air quality monitors may not place the BioWatch monitors in an optimal configurationfor a given area. Some outdoor pathogen releases, particularly those that might be small, reportedlymight avoid detection due to gaps or limitations in coverage due to siting, even though the monitorsthemselves were very sensitive. (35)

The exact locations of the BioWatch monitors are not public knowledge. The Departmentof Homeland Security does not confirm the locations of BioWatch monitors. (36) If the locations of thesemonitors were known with great certainty, it might become possible to avoid them, to degrade theirdetection capability, or to provide them false signals or information. The locations of the BioWatchmonitors determine the detection coverage areas and the security of the monitors. Some lawenforcement concerns which may have been employed in developing priorities for placing andoperating BioWatch monitors include: assuring the physical security of the monitors so that notampering occurs; guaranteeing that monitor filters arrive at the testing location in the same conditionas when they were removed from the monitor; and providing that the chain of custody for potentialforensic evidence is established.

A further concern regarding placement of some BioWatch monitors near EPA air quality sitesis that EPA monitors are not equally spaced within a city or an area. Even if the EPA monitors meetthe above criteria with respect to security, privacy, and access, the irregularity of placement andpotential gaps in coverage between these sites may cause them to be not entirely appropriate asBioWatch monitors. It is suggested by some that an outdoor biological warning system wouldrequire the placement of monitors as closely spaced as 300-500 meters. (37) Neither the officialrationale for BioWatch monitor placement nor who established the placement criteria has beendisclosed. It may be that the reported choice of sites reflects an effort to provide maximal coveragefor the population in a particular metropolitan area. An unnamed spokesman for the Department ofHealth and Human Services stated that the goal of BioWatch siting is to provide coverage for 80%of the population of a particular area. (38) Alternately, cost and ease of access are suggested as possibleadditional reasons for the reported use of EPA co-locations. (39)

Following a positive signal from a BioWatch monitor, the likely affected area might bedetermined through analysis and modeling of potential releases. Those determined to be inside areasaffected by the release might receive priority treatment. A recent Congressional hearing (40) cast light on the diversityof programs able to model gaseous releases, but also highlighted that there is not a single,acknowledged best method for determining the area of effect of a given release, especially in urbanareas where wind patterns and the effects of turbulence from building geometries is only partiallyknown. (41) Thus,determining the exact areas impacted by the release, and hence those individuals requiring prioritytreatment, may be more difficult if the monitors are sub-optimally deployed.

Analytical Issues

As stated above, the BioWatch Program is built from the successes of BASIS, developed bythe Department of Energy. (42) BASIS, which employs similar technology, was tested by theDepartment of Energy in a variety of situations, including laboratory environments and deploymentat the Salt Lake City Winter Olympics in 2002. (43) It is not fully known what potential changes were made to theBASIS equipment when it was adapted to serve BioWatch, and how applicable previous testingresults for BASIS are to BioWatch. Some question the ability of the BioWatch test methods todetect pathogens in a large city environment, especially one with considerable pollution and airborneparticulate matter that might affect analysis. (44)

Some are concerned that there may be naturally-occurring background levels of somepathogens in surveyed cities, leading to positive findings in the BioWatch program which do notresult from bioterrorism. (45) While PCR is a sensitive technique, it reports the presence orabsence of a DNA sequence, providing only a coarse scale of the amount of initial material. Thediseases caused by anthrax, plague, and tularemia bacteria, all on CDC's Category A list of biologicalterrorism agents, are not commonly found in humans, but they are diagnosed as naturally-occurringinfections each year in the U.S. (46) Certain of these agents are considered endemic, regularly presentin the environment, in certain parts of the country. The BioWatch Program appears to be premisedupon the assumption that all positive detections merit further investigation, even if there may be adetectable background level of these pathogens in some areas. In this regard, the BioWatch Programis a simpler methodological design than surveillance systems that detect deviations from ananticipated background event level. Such systems have the added burden of determining thresholdsabove background which are significant. Those concerned about detection of naturally occurringbackground pathogens question how response plans might take this possibility into account. Whenairborne tularemia bacteria was detected by BioWatch sensors in Houston, Texas, other information,such as the appearance of human illness, was sought to clarify the BioWatch result.

Further concerns with BioWatch implementation relate to the verification of positive resultsand the use of further testing to guide governmental response. While the number of false positivesarising with BASIS was determined to be very small, (47) it is unknown whether that rate is directly applicable to BioWatchequipment. The BioWatch collection filters, under vacuum airflow for several hours, have thepotential to dessicate and kill organisms collected on them, yielding positive PCR results that cannotbe directly confirmed by growth of a pathogen in culture. (48) PCR methods are based on the detection of DNA signatures;they do not require that the organisms be viable, nor do they distinguish whether organisms areviable or not. For many pathogens of bioterrorism concern, the "gold standard" confirmatory testis based on growth of the sample in culture. Besides providing clear confirmation of preliminaryresults, growing the organism provides options for further testing. For example, having viablesamples of the pathogen allows for molecular "fingerprinting" and other techniques to supportepidemiologic and law enforcement investigations, as well as allowing determination of antibioticresistance. There may be analytical techniques, other than culture, used to clarify PCR results fromBioWatch, and other activities that could be undertaken to corroborate initial findings, but whetherprotocols for these activities are established and communicated to the state and local authorities thatwould implement them is not publicly known.

The public health testing model for bioterrorism, in place during the anthrax attacks of 2001,incorporates confirmatory testing as one of its operational cornerstones. LRN laboratories usetrained personnel to expedite testing that confirms or refutes preliminary findings. One goal of theLRN is to minimize the time between an initial signal, such as a "positive" on a field-screeningdevice that is expected to yield some false positive findings, and a confirmed result. This processis designed to launch a public health response swiftly when it is needed, and avoid doing so whenit is not. A large-scale aerosol release of biological agents would necessitate a public healthemergency response of the highest order. While the BioWatch program is designed to detect apotential aerosol release quickly, if confirmatory testing is not available, it could lead to triggeringresponse activities erroneously, potentially consuming limited resources and damaging publicconfidence.

A final concern is the threshold for pathogen detection in the BioWatch system. Since PCRcan amplify very small amounts of DNA, such a system could be very sensitive, theoretically ableto detect a single pathogen. On the other hand, the pathogen deposition onto the filter depends onthe rate of air flow into the monitor. Thus, the pathogen release detection limit is a combination ofat least three factors: the concentration of aerosols passing over the detector; the duration that theaerosol mist is passing over the detector; and the amount of air collected through the filters duringthat time. (49) Since thesethree parameters of equipment performance are not publicly available, the actual detection limit forBioWatch is not publicly known. As a consequence, analyst opinion is mixed as to the utility ofthese monitors, with some expressing confidence that small releases could be detected, and othersexpecting that smaller outdoor releases would fall below the detection limit. (50) A very low detection limitis desirable because for some of the potential agents of bioterrorism, the infective dose in someindividuals may also be very low. (51)

The BioWatch program is considered labor intensive. (52) Collection of filters fromthe monitors, processing of the filters, and laboratory analysis all require human intervention. Additionally, the required laboratory work regularly consumes chemical reagents and disposableequipment, incurring significant operational cost. Finally, there are additional costs in administering,overseeing, and managing personnel and mandatory reporting related to this program. Initialestimates of the costs of the BioWatch program are reported to be approximately $1 million in initialequipment costs per city, followed by operational costs of $1 million per city per year. (53) Since the BioWatchProgram was launched in January 2003, it is likely that a more exact accounting of the recurringcosts of this program will become available in the future.

Public Health Response Issues

If an aerosol release of a biological agent were detected, a two-pronged response would beinitiated, with state and local public health agencies in charge of an epidemiologic investigation, andthe Federal Bureau of Investigation (FBI) in charge of a law enforcement investigation. (54) The public healthconsequence management plan for the BioWatch program is not publicly available, but based on ageneric model for public health activities following a bioterrorism event, it is likely to include suchactivities as: expanded laboratory investigation, identification of affected populations, guidelines forcountermeasure distribution, considerations for management of mass casualties, and potentialrestriction of movement of individuals in the case of a communicable agent. (55) A likely first step wouldbe aimed at further sampling to quickly confirm and clarify any positive results from the BioWatchsystem, including an attempt to isolate viable organisms, but with an urgency to minimize the timespent between an initial alert and a decision to launch a public health response. The public healthresponse to a suspected aerosol pathogen release is likely to be massive and difficult to implementin a limited manner. It is, in fact, the intent of the BioWatch program that the public health responsebe launched as quickly as possible following a detected release. An often cited theoretical modelof casualties following mass exposure to anthrax concluded that rapid distribution of antibioticsfollowing detection of the event is a critical element in reducing fatalities, and could represent apotential bottleneck in the response. (56)

Another concern is the burden on a public health workforce asked to support a new programwhen faced with naturally occurring challenges, such West Nile virus and Severe Acute RespiratorySyndrome (SARS). At a July 2003 hearing on biodefense readiness, CDC Director Julie Gerberdingnoted,

... in the middle of our smallpox program, we did haveto take the very same people and work on a SARS outbreak, and then a monkey-pox outbreak, andnow a West Nile outbreak, and we have a number of very high priorities throughout CDC and thepublic health system that compete for the same personnel. ... we have been in crisis mode for twoyears now. (57)

State public health laboratory workers have voiced concern about meeting their public health dutiesdue to the increase in responsibility for certain federal programs. (58) Similar concerns werevoiced about impacts on the public health infrastructure with respect to smallpox vaccination andterrorism preparedness. (59) Since the day-to-day operation of the BioWatch program wastransferred to state and local public health laboratories, the Department of Homeland Securityattempted to mitigate these impacts by providing for hiring of laboratory personnel dedicated tosupporting the BioWatch program. (60) Additionally, direct costs of the program, including consumablessuch as biological reagents, are provided for by DHS.

Future Directions of the BioWatch Program

Several aspects of the BioWatch Program are undergoing further development. As statedabove, the initial implementation of the system expanded to a reported 31 cities, (61) with potentially more areasunder surveillance in FY2004. (62) This expansion may lead to efficiencies, and the alleviation ofsome current concerns, as experience is gained and problems are solved.

The Department of Homeland Security, through the Science and Technology Directorate, isalso requesting proposals for next-generation detection systems for biological countermeasures. TheHomeland Security Advanced Research Projects Agency issued Research Announcement 03-01which requests submissions for systems able to continuously monitor urban areas for biologicalagents as well as new indoor monitoring systems. (63)

Additional work is being performed at Department of Energy National Laboratories tocomplete commercialization of an automated pathogen detection and analysis capability. Thisproject, called the Autonomous Pathogen Detection System, would result in a completely automatedsystem. (64) Thedevelopers expect to have the ability to measure up to 100 different agents and controls per sample,with low false positive and false negative rates and a relatively low cost per assay. (65)

Research and development efforts on other detection systems continue. For example, theDepartment of Defense Chemical and Biological Defense Program continues to develop and deploytechnologies for instantaneous detection of biological and chemical weapons. (66) Other prospectivetechnologies include the SensorNet program, which reportedly is developing a capability to detectchemical, biological, and radiological dispersion, (67) the Urban Atmospheric Observatory, (68) whichaims to determinethe atmospheric patterns in an urban environment, and DCNet, a program to map wind currents inthe Washington, DC area. (69) Such research may eventually develop the next generation ofbiological detection equipment and could provide valuable raw data for analysis of results arisingfrom the current BioWatch monitors. A better understanding of urban air flow may provide for amore exact determination of areas affected by an aerosol release. (70)

Policy Concerns

Many aspects of the BioWatch Program raise policy questions Congress may consider in thecoming months. One question addressed may be whether this program is an appropriate federalresponse to the threat of bioterrorism, both in scale and scope. If it is deemed to be, Congress maybe interested in how detection systems, such as BioWatch and other prototype systems, are beingused by the Department of Homeland Security to increase national security. The BioWatch Programwas deployed rapidly, with little publicity, but lessons learned during this process may be applicableto other detection systems that the federal government develops. Congress may also wish to considerhow the performance of this system is measured and determine whether the funding level that theBioWatch Program receives is appropriate for its performance or effectiveness. Future developmentof more advanced monitoring systems and further refinement of the BioWatch monitors may alsobe areas of Congressional interest. Another issue is how results from the BioWatch monitors areintegrated into state and federal response plans, especially since BioWatch is a locally operated,federally funded program.

Significant Role of Detection Systems in DHS Strategy

Distributed detection networks appear to play a significant role in the Department ofHomeland Security's strategy for protecting the United States. The Department of HomelandSecurity's Directorate of Science and Technology is establishing a Biological Warning and IncidentCharacterization (BWIC) system. BWIC consists in part of environmental monitoring networks inselected cities with direct agent detection and a nationwide biosurveillance system looking forindicators of biological agent exposure in people, animals and plants. The DHS Under Secretary forScience and Technology McQueary testified that the BWIC system will be available as a pilot inFY2004. (71) The DHSalso received FY2004 funds for programs to develop and demonstrate advanced technologies,including sensors, to detect radiation using systems distributed over a geographic area.

In the further development of such national-level detection systems, what features mightpotentially be addressed, and the priorities assigned to them, is open to debate. One priority settingdecision might be the extent to which the BioWatch system is further deployed. This decision mayprompt additional policy questions. Will further installation of these systems occur only inmetropolitan areas, or will smaller urban, suburban, and/or rural areas also be eventually includedunder BioWatch coverage? Should more monitors be installed in cities currently under BioWatch,so as to increase the likelihood of detecting a small release? Should monitors be installed insidebuildings or public transportation, where people may be concentrated? Some experts have criticizedthe BioWatch program for being primarily designed to detect large releases while not detecting thepotentially more likely small releases. (72) Others point out that during the Salt Lake City Olympics BASISwas successfully installed in sporting venues and transport hubs where small releases might bedetected. (73) On theother hand, deploying multiple sensor units within a particular area may lead to significant overlapbetween sensors, providing diminishing returns per monitor. A complicating factor is the cost ofexpanding the BioWatch Program and the increased likelihood of false positives. Since biologicalterrorism is often considered to be a low probability/high consequence event, the risk of an eventoccurring is balanced against the costs of maintaining the detection infrastructure necessary to detectthe event. Unlike previous investments in public health preparedness, the BioWatch Program maynot have dual-use application, being predominantly applicable only as an anti-bioterrorism program. Congress may choose to fund other programs which have greater dual-use application to gain benefitfrom such funds if no bioterror event occurs.

Another area of potential interest to Congress may be the method DHS used to prioritizedevelopment and deployment of national monitoring systems. Other federal agencies have programsto develop biodetectors and monitoring systems. These systems use a variety of techniques to detectaerosolized pathogens, but have often contained undesirably high false positive rates or lowsensitivity. For example, the Department of Defense is developing a "stand-off" detection systemfor some uses rather than a point detection system, as is employed by DHS in the BioWatchProgram. (74) In militarysettings, the ability to determine whether a threat is posed by an aerosol cloud at a distance, allowscombat troops to don appropriate gear and equipment. Also, the Department of Defense focuses ondetection systems with real-time detection, (75) attempting to develop a "detect-to-warn" rather than a"detect-to-treat" capability. These systems provide higher false positive rates than that reported forBASIS. Because of the ready availability of protective equipment, including masks and suits, andthe high training provided to troops regarding this equipment's use, false positives requiring thedonning of protective gear are more acceptable than in a civilian setting. Further research into suchtechnologies and assessment of the potential performance of these military detector systems whenplaced in a civilian environment may be areas for future study. Congress may also wish to considerhow DHS plans to assess the effectiveness and performance of the BioWatch Program. Sinceevaluations for homeland security are still being developed, judging the success of the BioWatchsystem may prove challenging in the short term.

Deployment of Other DHS Programs

Another issue is whether the deployment of the BioWatch program, using federal governmenttechnologies, government contractors, and providing little official information with regards tocapabilities and locations, is an appropriate approach to homeland security vulnerabilities. Whilethe deployment of BioWatch as a federal program may have increased the speed of implementationand thus enhanced homeland security, a question remains as to whether a more effective, efficient,or inexpensive system might be developed or deployed if greater public and commercial input wereinvolved. Other homeland security projects, such as radiation detectors, were developed andcommercialized by engaging competitive market forces through requests for proposals. (76)

Evaluating Effectiveness

Frequently expressed concerns about the BioWatch Program are its lack of ability to detectsmaller outdoor releases, its potential for false positives, and its capabilities in an urban environment. One way to address these concerns is by disseminating information about performance characteristicsof the BioWatch Program. This type of information is available for other military systems, especiallychemical detectors. For example, the Department of Defense released the detection levels for somechemical detection equipment, (77) and some performance characteristics, such as false positiverates, are provided for BASIS. (78) Even if these metrics were not publicly disseminated, providingconcrete information at the state and local level might enhance the BioWatch effectiveness. Advantages from early detection depend on a timely response to a biological release. If state andlocal officials lack confidence in the monitor performance, consequence management may bedelayed, leading to greater casualties. (79) Alternatively if officials overestimate the monitor capability,consequence management activities may be engaged even when there is no need, consumingvaluable resources and generating unnecessary public anxiety. In the case of the BioWatch detectionof airborne tularemia in Houston, the distribution of countermeasures was not begun, pending thecollection of additional information. One option would be to further refine the decision-makingprocess invoked upon a positive finding to more optimally achieve the goals of rapid response to abioterror event.

Determining the effectiveness of the BioWatch Program in achieving its public health goal,to minimize casualties by detecting exposures more rapidly than would otherwise have occurred, willbe difficult in any circumstances. Assessments of public health effectiveness are typicallyconsidered in the context of opportunity cost; are allocations of funds and person-hours worthwhile,or might they be better used elsewhere? BioWatch, designed to detectlow-probability/high-consequence events, is unlike public health surveillance programs, which trackconditions expected to occur in the population. CDC publishes an evaluation protocol forsurveillance systems, "to promote the best use of public health resources through the developmentof efficient and effective public health surveillance systems." (80) Information about anumber of the performance characteristics typically described for surveillance systems -- includingflexibility, data quality, and representativeness -- is not available to the public for the BioWatchProgram. A senior CDC official stated that BioWatch is in the "proof of concept" phase, a relativelyearly stage of technology development, and notes that CDC is, "trying to build systems to assure thatonce we have true positives, we can mobilize a response rapidly, but also develop a system for falsepositives which we feel could be a potential problem in the future." (81) Efforts to explain thesystem to those needing to know, and to coordinate the activities of multiple agencies at the federal,state and local levels, are ongoing. (82)

The BioWatch Program draws upon the expertise of three federal agencies, the Departmentof Homeland Security, the Department of Health and Human Services (through the CDC), and theEnvironmental Protection Agency. Which agency is best suited to provide oversight and evaluationof the BioWatch program is an unresolved question. DHS funds and currently oversees the program,but some may argue that the BioWatch Program is inherently a public health program. In this case,the Department of Health and Human Services, potentially through the CDC, would be best equippedto assess the effectiveness of the program. The CDC has experience in federal/state relationsregarding public health and in the evaluation of public health surveillance systems. Also, the CDCmay be best qualified to judge the validity of response and consequence management plans followinga BioWatch positive. Advocates for such a view might point to the retention of bioterrorism-relatedcivilian countermeasure research and development by HHS, in the Homeland Security Act ( P.L.107-296 ), as indicative of the expertise retained within that Department. Others may assert that theBioWatch Program is a homeland security program, in which case DHS is the logical choice for soleoversight and assessment of this program. Since the technologies involved during BioWatchdevelopment originated with elements of DHS, that agency may be uniquely qualified to assess thestate of development and deployment of the system.

Because this program cuts across the expertise of different federal agencies, oversight andevaluation of the BioWatch Program will likely include the federal agencies involved. The precedentset in the Homeland Security Act ( P.L. 107-296 ), where a collaborative approach between theSecretary of Health and Human Services and the Secretary of Homeland Security is required withrespect to civilian human health-related research and development activities relating tocountermeasures for chemical, biological, radiological, and nuclear and other emerging terroristthreats, (83) may be amodel for assessment of the BioWatch Program. Determining the relative authorities of theparticipating agencies may be an area of Congressional interest.

The Homeland Security Act ( P.L. 107-296 ) also established a Homeland Security Institute. The Act allows this institute, following a determination by the Secretary of Homeland Security, totake on the duties of "evaluation of the effectiveness of measures deployed to enhance the securityof institutions, facilities, and infrastructure that may be terrorist targets," "assistance for Federalagencies and departments in establishing testbeds to evaluate the effectiveness of technologies underdevelopment and to assess the appropriateness of such technologies for deployment," and "designof metrics and use of those metrics to evaluate the effectiveness of homeland security programsthroughout the Federal Government, including all national laboratories." (84) Some may advocate thatsuch an institute would provide the necessary mixture of federal, private, and public opinions to fullyevaluate the different components of the BioWatch Program.

Funding for the BioWatch Program

The degree to which DHS should focus its spending on such a program is an area of potentialCongressional interest. The DHS reportedly spent approximately $40 million in FY2003 on theBioWatch program. (85) FY2003 funding for the BioWatch Program was reprogrammed from part of the $420 milliontransferred from the Department of Defense to DHS with the National Bio-Weapons DefenseAnalysis Center. (86) The$40 million for the BioWatch Program represented 12% of the $340 million dedicated to BiologicalCountermeasures in FY2003. For FY2004, the request for the Biological Countermeasures programwas $364 million. Congress provided $199 million, in addition to $68 million in unexpendedFY2003 funds, for a total of $267 million, and increased the amount dedicated to BioWatch. Theconference report accompanying Appropriations for the Department of Homeland Security ( P.L.108-90 ), in the section on Biological Countermeasures, states "an additional $15,000,000 is providedfor the urban monitoring program." (87) According to the White House, a total of $38 million, or 14%of the Biological Countermeasures budget, will be spent on the BioWatch Program. (88) Whether this focus shouldcontinue, the funding levels for the BioWatch Program, and how high a priority this specificdetection system should be for DHS are areas where Congress may exercise its oversight role.

Future BioWatch Development Priorities

Several of the technological aspects of the BioWatch Program are areas where gains may beachieved. Areas where successful upgrades of technology might have significant benefits includereducing the cost of each BioWatch monitor, both in initial capital outlay and in daily operationalcost, further development of detection methods for more pathogens, or for genetically modifiedpathogens, and increasing the automation of the BioWatch technologies. Improving the currenttechnology might allow coverage of more people and/or detection of more pathogens for the currentcost. Additionally, research into alternate sensor technologies, such as biological assays, laserfluorescence, and other more novel techniques, and topics such as more efficient collection andanalysis tools are currently funded by the federal government. Inclusion of such advances intoBioWatch or other detectors may be worth consideration.

Coordinating Bioterrorism Testing

The BioWatch Program and the Laboratory Response Network (LRN) share common goalsin providing laboratory support for detecting a bioterrorism event, and both are deployed in state andlocal public health laboratories, but important differences may hamper their effective coordination. The BioWatch Program was developed by the Department of Energy and EPA and was deliveredto state and local public health laboratories in a near-final state in early 2003. (89) It is managed and fundedat the federal level by the Department of Homeland Security, with state and local public healthagencies responsible for on-the-ground management of laboratory activities and response to positivefindings. The LRN, in contrast, was developed by the CDC, FBI, and state and local health agencies,with the first set of test methods developed prior to the anthrax mailings of 2001. The LRN ismanaged and funded at the federal level by the Department of Health and Human Services throughCDC, and, in a fashion similar to the BioWatch Program, state and local public health agencies areresponsible for on-the-ground management of network assets and response to positive findings. (90) The LRN has the benefitof a longer history as a civilian public health program, during which time policies, procedures andprotocols have matured.

The BioWatch program shares some operational similarities with the LRN, but there may beareas in which simultaneous operation of the two systems might prove difficult. Both systems wouldlikely be in significant use during a bioterrorism event, and handling large influxes of both BioWatchand environmental samples might cause competition for limited resources. Conflict might arise inareas including prioritizing samples for testing (triage), referral testing and data management. (91) On the other hand, closeinvolvement of BioWatch operation and testing with the public health community may prove to beof benefit in the case of an actual attack. In a fact sheet released at the signing of the FY2004Homeland Security appropriations bill ( P.L. 108-90 ), the White House noted that the BioWatchprogram and the LRN are both early-detection programs for bioterrorism, and that federal partners,"are working with state and local officials to implement an effective consequence management planthat incorporates the BioWatch system." (92)

Clarifying Roles and Responsibilities

The BioWatch Program is a federal program, while first responders and some immediatedecision makers are state and local officials. Since the results are generated from federal equipmentoperated by federally funded workers in a state or local public health laboratory, which entity bearsultimate responsibility for the functioning of the system? What is the chain of authority forBioWatch results? While it has been reported that states are developing response plans in the caseof BioWatch positives, (93) the degree of coordination between federal and state officials,and the mechanisms of federal assistance to states in such an event, appear unclear at this point. Theresponse plans developed on a state and local level may have significant differences in approach,depending on the particular resources available, leading to inconsistent responses to BioWatchpositives. Coordination between adjacent states, and especially coordination with federal authoritiesin a potential multi-state event, is crucial to limiting the public health impact. A variety ofconsiderations, including means to provide security clearances to essential state and local personnelso they are fully involved in planning and response activities, remain to be clarified. (94) The Department ofHomeland Security is developing an updated national response plan which will define the roles thevarious federal agencies will play in a national emergency. (95) Areas of potentialCongressional interest include the specificity of federal guidance to states with respect to resultsfrom the BioWatch program, the coordination and cooperation between federal and state resourcesfollowing a BioWatch positive, and the incorporation of BioWatch results into this national responseplan's implementation.

Conclusion

With early detection and treatment of those exposed to biological weapons, illness andsubsequent fatalities may be minimized, and the presence of BioWatch in urban areas may serve asan effective deterrent to potential bioterrorists. Some have questioned the effectiveness of such asystem. With a limited number of monitors within a metropolitan area, these critics questionwhether potentially more likely smaller-scale events are detected. Others question whether such asystem will provide dependable results upon which sound decisions are made.

Since much information on BioWatch has not been released to the public, it is difficult toevaluate criticisms of the system. Many of the technical issues raised may have been or are beingaddressed by the Department of Homeland Security. Agreements on coordination between state andfederal authorities may be developed but not released. Congress, in overseeing the use of limitedhomeland security resources, may wish to further assess and oversee the impacts of BioWatch andits further development.