LIVERMORE-- Recent progress in technology development to counter biological and chemical terrorism has been "unprecedented," believe three Lawrence Livermore National Laboratory researchers
In a review article published Friday in the journal Science, the LLNL scientists note that while important challenges remain, new detection systems show increased sensitivity, greater automation and fewer false alarms.
"Ongoing challenges include approaches to respond even more rapidly, more cost-effectively and with the greatest likelihood of minimizing health risk and collateral damage," they write.
The review paper was written by Pat Fitch, leader of the Laboratory's Chemical and Biological National Security Program; Ellen Raber, head of the Environmental Protection Department; and Dennis Imbro, associate program leader of the Chemical and Biological National Security Program.
Technologies for countering bioterrorist agents are improving, the three researchers say, and are approaching the sophistication of technologies for fighting chemical warfare agents.
Even so, improvements are still needed for chemical sensors to meet health-effect-level sensitivities for protecting civilians and reducing high false-alarm rates, the authors write.
Marked advances have been made during the past two decades in biological detection, where there has been a combined 1,000-fold improvement in sensitivity and specificity, Fitch said. (Sensitivity refers to needing smaller amounts of material for detection, whereas specificity involves making the identification without false alarms).
One biological detection device described in the paper is the Biological Aerosol Sentry and Information System (BASIS), an environmental monitoring system used at the 2002 Winter Olympics.
Developed by Lawrence Livermore and Los Alamos national laboratory researchers, BASIS relies on a network of sampling stations to collect aerosol samples, which are then transported to a central laboratory and analyzed for selected pathogens.
Since its first deployment in 2001, BASIS has performed about 400,000 diagnostic tests of complex environmental samples, with no false alarms. BASIS uses a two-stage test, first screening a single specific sequence of DNA and later checking four or more additional DNA sequences. This is analogous to looking for a single matching curve in a fingerprint as a first test. Whenever an initial match is found, additional curves from other parts of the fingerprint are used to increase the accuracy of the test.
In addition to its deployment at the Salt Lake City Winter Olympics, BASIS has been used in New York City (for the first anniversary of Sept. 11) and in Albuquerque, N.M., among other sites.
"The real test of a biological detection system is when you have a small amount of a pathogen, you don't have much time to do the test and there's a downside to saying it's there when it's not there," Fitch said. "Any system that gets it wrong for a major event won't be used again."
Among the reasons cited by Fitch for the substantial improvement in biological detection are the ability to rapidly analyze DNA via the polymerase chain reaction (PCR) technology, the development of very specific DNA signatures for pathogens and the ability to do many tests and controls simultaneously.
In their review paper, Fitch, Raber and Imbro note that medical interventions are most effective when implemented soon after exposure and before the onset of symptoms.
During the inhalational anthrax events in 2001 in the United States, no known deaths occurred among the approximately 10,000 potentially exposed individuals who received pre-symptomatic treatment, whereas five deaths resulted among those who received post-symptomatic medical attention.
In the Science paper, the three Laboratory scientists describe a decision-making framework of four phases for guiding actions following a terrorist attack, which was developed by Raber and others in a 2002 paper on risk analysis.
The four phases identified are: notification, first-responder, characterization and restoration (or decontamination and remediation).
In the restoration phase, final acceptable levels of cleanup for buildings must be determined, as well as cost-benefit analyses of the cleanup.
For the anthrax exposures in the Hart Senate Office Building and the Washington, D.C. Brentwood Post Office, decontamination was continued until no anthrax growth could be found in swab tests to ensure health risks to building occupants were minimized.
In the view of the three authors, specific cleanup standards for agent decontamination of buildings have been lacking or controversial.
Researchers at three national laboratories - Sandia, Lawrence Livermore and Los Alamos - have or are developing various environmentally acceptable decontamination technologies.
The Livermore decontamination agent, known as L-gel, has been effective in a series of chemical and biological agent tests on a variety of substrates. The Sandia formulation, tentatively called Decon Foam 100, is available through two commercial companies.
Another promising decontamination technology has been developed by a British company, according to the authors.
Although these technologies are effective for surface decontamination, additional work is needed for building decontamination where gaseous decontaminants are typically required. The huge infrastructure requirements currently necessary for effective decontamination continue to impose long time delays and have potential for major economic impact.
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