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Biosecurity & Bioterrorism: Containing and Preventing Biological Threats
Chapter 13
Consequence Management and a Model Program
Learning Objectives
Discuss consequence management as it applies to an act of bioterrorism.
Define autonomous detection system and discuss concerns for employment of such a system.
Describe the function and operation of the biohazard detection system, which is deployed throughout the United States Postal Service.
Discuss the USPS Continuity of Operations Plan for dealing with a positive biohazard detection system signal.
Discuss current initiatives in military biodefense aimed at providing continuous monitoring for biothreat agents.
Key Terminology
Consequence Management
Autonomous Detection System (ADS)
Biohazard Detection System (BDS)
Concept of Operations (CONOPS)
Reaction to Amerithrax
US was focused on the events of 9/11
Anthrax-laced letters showed us how vulnerable we were to an act of bioterrorism
Tremendous number of hoaxes perpetrated along with false alarms
Response organizations were overwhelmed
American Postal Workers Union demanded that the USPS protect the workforce
Questions at that Time
What should be done to immediately protect the workforce and notify them of the existing threat?
What was the extent of the contamination (how many facilities)?
What was the existing threat to postal workers?
How would the contaminated facilities be cleared and put back into operation?
What should and could be done if the attacks continued?
What obligation do USPS officials have to protect their workers from the threat?
Quotable Quotes
In this time of heightened alert, the employer must provide adequate and timely information that the employee is afforded adequate protection from harm. It is never understandable that an employer can deny or inhibit this opportunity for self protection.
William Burrus, President, APWU
March 26, 2003
Consequence Management
Predominately an emergency management function.
Relative to terrorism incident operations, consequence management includes measures to protect public health and safety, restore essential government services, and provide emergency relief to governments, businesses and individuals affected by the consequences of terrorism
Seiple, 1997
Consequence Management: Domestic Response to Weapons of Mass Destruction
Ways and means to alleviate the short- and long-term physical, socio-economic, and psychological effects of a chemical or biological attack
Coordination of international, national, regional, and local assets to deal with the effects of such an attack
Preparatory work in response to a WMD threat:
site surveys
assessment of the ability of local hospitals to treat or decontaminate victims
size, condition, and locations of local stocks of various antidotes
Preparation could include determining the locations, size, and availability of other national antidote stocks as well as international stocks available to support planning for surge capacity
Seiple’s Recommendations
Detection is the first line of defense; it is where tactical consequence management begins
Mandatory consequence management awareness and training to ensure a lowest common denominator of knowledge at the local, regional, and national level.
Identify, train, and mentor individuals within organizations, which would thereby create a new culture determined to deal with the consequences of terrorist use of WMD.
Develop a tiered continuum of response.
Crisis Management
Sensing the urgency of the matter
Thinking creatively and strategically to solving the crisis
Taking bold actions and acting courageously and sincerely
Breaking away from the self-protective organizational culture by taking risks and actions that may produce optimum solutions in which there would be no significant losers
Maintaining a continuous presence in the rapidly changing situation with unfolding dramatic events
Autonomous Detection Systems
Continuously samples the environment (e.g., air or water)
Mixes that sample with a special buffer solution. An automated detection assay (e.g., a real-time PCR test or an immunoassay)
Analyzes the trapped material at a defined sampling interval
Incorporate an alert notification system to trigger a response once a positive signal has been generated
Result is an approximate real-time detection and alerting system
ADS & Bacillus anthracis (BA)
Every agency that deploys an ADS must develop detailed plans for responding to a positive signal (Meehan et al., 2004)
Plans should be formulated into Concept of Operation (CONOPS) documents that embody consequence management principles
Responding to ADS detection of B. anthracis involves coordinating responses with response agencies and other stakeholders.
CONOPS Guidelines
Immediate response and evacuation
Decontamination of potentially exposed workers to remove spores from clothing and skin and prevent introduction of BA into the worker's home and conveyances
Laboratory confirmation of an ADS signal
Steps for evaluating potentially contaminated environments
Post-exposure prophylaxis and follow-up
Image courtesy of USPS
Biohazard Detection System (BDS)
Developed for the United States Postal Service
A model system resulting from a cooperative effort led by Northrop Grumman
Partnering Organizations:
Cepheid, Inc
Smiths Detection
Sceptor Industries
BDS Summary
Automates and integrates air sampling and subsequent analysis using polymerase chain reaction technology
As letter mail is processed down to a single stream of mail thought an Automated Facer Canceller system (AFCS) it is screened for Bacillus anthracis (BA) spores
Consumables (cartridges and buffer solutions) are replenished daily and weekly with no skilled labor required to operate the system
Critical Thinking
The BDS has been functional since 2004. Since that time, more than ten million individual tests have been run and there hasn’t been a single positive test result (or false positive) in the testing of more than 100 billion pieces of mail. The United States Postal Service has serious financial problems. How much longer will they continue to keep the BDS in operation? The answer to this question is not known. There are many factors that weigh heavily on USPS administrators in justifying the continuation of this program. What might they be? Liability, worker safety, sense of security?
Also, ricin has been sent through the mail several times since the inception of the program. Presumably, this represents a serious threat to postal workers and the general public, but there’s no testing in place for this agent. Why? Would a PCR test detect a toxin?
Required Technical Specifications
Sensitivity is a measurement of how few organisms can be present in a sample and still be detected. Based on the specific protocols in the GeneXpert® cartridge and knowledge of infectious dose ranges for anthrax, sensitivities were established as:
Less than 50 BA spores per reaction in a USPS specimen
Less than 30 BA spores per reaction in pure water or buffer
Specificity is a measure of how often a true negative is called negative by the method. False positive results can cause unnecessary and expensive responses or work stoppages.
False positive rate target = < 1:500,000 (99.9998%)
No cross-reactivity with nearest neighbor organisms or those found as normal content of the raw sample
Non-Determinate Rate (due to all test failures, mechanical, software, or reagent) of less than 1%
Speed of less than 35 minutes to result (after raw sample transfer to cartridge)
Algorithm: Continuous, on-site testing with no human intervention
BDS Timeline
BDS pilot program began May, 2002
Preproduction phase (November 2002–May 2003)
Production deployment started in early 2004
Deployment completed in December of 2005
BDS Validation
Extensive effort involving numerous federal agencies (CDC & DOD)
The Office of Science and Technology Policy (OSTP), Executive Office of the President, formed an interagency working group (IWG) to critically evaluate the USPS plans and data from BDS pilot studies. That group concluded in a report from the IWG and the letter from the House Of Representatives Committee on Government Reform, dated November 25, 2002 that:
the BDS and GeneXpert system demonstrated performance consistent with laboratory-based state of the art systems. They found the system fully capable to meet the strict USPS performance requirements (OSTP, IWG Report, 2005).
The GeneXpert® System
GeneXpert® cartridges handle large volumes of raw sample, extract and concentrate the target organisms, remove extraneous and inhibiting substances and purify and concentrate the organism’s DNA, all automatically.
The concentrating of target organisms from large sample volumes enables the GeneXpert to meet the sensitivity requirement
The BA Cartridge
Images courtesy of Cepheid, Inc.
Biosensor Process
Real Time PCR
‘A’ - the probe hybridizes to the gene sequence it was designed for while polymerization is taking place
‘B’ - the probe is displaced by the DNA polymerase and cleaved in ‘C’.
‘D’ - the fluorochrome attached to the probe is released into solution and is later excited by a specific wavelength of light.
The excitation is detected and measured.
When that signal exceeds a specific limit, the signal is considered positive
Image courtesy of Cepheid, Inc.
Screen Shot of BDS Biosensor
Result
Growth curves
Image courtesy of Cepheid, Inc.
Attributes of the BDS Biosensor
PCR is a well-established method for the highly sensitive and specific detection of cells at extremely low levels
Gene sequences are amplified from very few copies
Employs a four-color fluorescent real-time PCR system
Four different targets and/or controls are measured and distinguished simultaneously. For the USPS anthrax test, the assay detects:
Two key virulence genes [pX01 gene (pag), and pX02 gene (capB)]
An internal control designed to emulate those targets
A separate sample prep control
Detection of the two key virulence genes is the best approach to achieving the specificity requirement
The probability that a test would be simultaneously falsely positive for two separate genes is extremely improbable
BDS Alert
Sample to LRN
Positive LRN PCR
Negative LRN PCR
Confirmed LRN Culture
Negative LRN Culture
Evacuate facility/shut down HVAC/Notification
Antibiotic distribution plan in “watch” mode
Distribute 5-day course of antibiotic prophylaxis for all employees
60-day antibiotic prophylaxis and vaccination for selected employees
Collect demographic data
Collect Epi Data (upstream analysis)
0-8 hours
9-24 hours
25-120 hours
Initiate environmental sampling to find source of contamination
2 cartridges, liquid reserve
Notify USPS
Isolate to CDC
Alert staff and public off-site
Responding to a BDS Alert
Employee wash change clothes/shoes
High risk: shower
Collect employee data
USPS CONOPS
Critical Thinking
In the fall of 2001, we experienced an act of bioterrorism when Bacillus anthracis spores were intentionally released through several small envelopes placed in the U.S. mail. The USPS turned to industry and asked for proposals to a solution to this problem. Several small companies teamed up with a major defense contractor, Northrop Grumman, and developed the biohazard detection system. It took two years to fully develop the system and nearly 18 months to validate it. The USPS began deployment of the BDS in late 2004. The system is now fully deployed and actively screening letter mail in 282 mail sorting facilities across the United States. So far, billions of pieces of mail have been screened and there have been no false positive or true positive results.
Do you believe that having this system in place is the reason why we have not seen another attempt at using the U.S. postal system to disseminate biological agents?
How has it performed since?
Deployment of BDS completed at 272 sites across the US
As of 2007, more than ten million tests have been performed during screening of more than 100 billion pieces of mail
There have been no false positives (or true positives reported)
Early on, there was some trouble with non-determinant results (neither positive or negative) - due to contamination or debris – problem has been rectified
Discussion Questions
How do the CONOP measures for the BDS compare to the recommendations of Meehan and colleagues (2004), previously outlined in the section of this chapter on Autonomous Detection Systems?
How do the actions outlined in the CONOPS section of this chapter fall into line with RAIN?
What are the benefits and features of having an ADS installed? What are the liabilities?
Chapter Summary
The Amerithrax incident was a wake up call for government officials and the American public
A solution was needed to protect workers and ensure the safety and integrity of the US mail
The commercial sector worked quickly and efficiently to build the solution that the USPS needed
Autonomous Detection Systems are built from impressive and intricate technologies. These systems enable us to monitor the environment for a potential attack from a bioterrorist
The Biohazard Detection System is a perfect example of a model system. It is intended to take advantage of exposure surveillance compared to disease surveillance, which reduces the timeline for detecting a bioterrorist attack, thereby reducing the risk of disease through post-exposure prophylaxis
Consequence management and CONOPS are important, well thought out programs aimed at taking advantage of these systems to the fullest extent possible