Between 2003, when the nationwide network of air samplers was first deployed, and 2006, officials at the federally funded Lawrence Livermore National Laboratory filed five patent applications aimed at improving BioWatch's reliability.
"The existing methods for detecting" a release of disease-causing organisms into the environment were "inadequate," according to a patent application filed on behalf of Livermore scientists in December 2006.
The application cited a "higher than acceptable rate of false positive ... results," adding: "False positive results lead to confusion regarding whether [a pathogen] is actually present and whether protective measures should immediately be implemented."
The previously unpublicized documents contradict repeated assertions by the Department of Homeland Security, which oversees BioWatch, that the system has performed flawlessly. The department's chief medical officer, Alexander Garza, said last month that "there has never been a false positive result."
President George W. Bush? unveiled BioWatch in his 2003 State of the Union address, saying it would "protect our people and our homeland" against a rogue state or terrorist group. Since then, the Bush and Obama administrations have spent about $1 billion to deploy detection equipment in more than 30 U.S. cities and at major spectator events, including Super Bowls and national political conventions.
As the Los Angeles Times reported last month, the system has been plagued by false alarms ? at least 56 in all ? that triggered tense, high-stakes deliberations over whether to order mass evacuations, distribute emergency medicines or shut down major venues.
In each case, health authorities decided, sometimes with great trepidation, to disregard BioWatch. No evidence of an intentional release of a pathogen has ever been found.
That history has caused state and local health officials to call the system ill-conceived or unworkable. Scientists at the U.S. Centers for Disease Control and Prevention? told White House aides in November that they would not release emergency medications based solely on a BioWatch alert. And federal officials have given up plans to deploy the system in airports for fear of needlessly disrupting travel.
Nonetheless, Homeland Security officials have continued to defend BioWatch, insisting that it has been an "enormous success story," as a Bush administration appointee told Congress in 2007.
BioWatch uses vacuum-powered samplers that suck air through composite filters, which are removed daily and analyzed at public health labs for signs of anthrax, smallpox, plague or other deadly pathogens. Janet Napolitano, secretary of Homeland Security, is expected to decide soon whether to approve an automated "lab in a box" version that would cost an additional $3.1 billion over the next five years.
Most of the documented false alarms have involved the supposed detection of tularemia, a bacterium that can infect or kill humans in lower concentrations than anthrax or other agents.
On the closing day of the 2008 Democratic National Convention in Denver, for example, BioWatch signaled the presence of tularemia at the convention site, threatening to disrupt plans for Barack Obama's speech accepting his party's presidential nomination.
After six hours of deliberations and further testing, state health officials decided that the alert had been erroneous, and Obama gave his speech on schedule.
The reason for such false alarms is that BioWatch has been unable to distinguish between the tularemia bacterium and genetically similar organisms that pose no harm to humans, according to scientists with knowledge of the system.
Three of the five patent applications filed by the Livermore lab involved efforts to better distinguish between the DNA of tularemia and that of its close cousins.
"A more reliable method" of detecting tularemia, the applications said, "would reduce the occurrence of false positive ... results and provide decision makers with greater confidence in implementing appropriate countermeasures."
The other patent applications dealt with two other pathogens targeted by BioWatch ? the germs that cause brucellosis and plague.
Patents were granted in response to all five applications.
los angeles kings earth day timothy leary jonathan frid pujols watchmen hitch
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.