features air samplers that suction air through filters and
collect any airborne microbes onto a filter’s surface.
Above, the bar code of a single filter is scanned.
ONE of the most frightening
weapons in a terrorist’s potential arsenal is the airborne
release of deadly microbes such as those that cause anthrax or
smallpox. In most cases, the prognosis for victims from such an
attack depends on how quickly antibiotics, vaccines, or other medical
treatment can be administered. And treatment options can’t
be determined until the pathogen has been accurately identified.
A quick turnaround time can thus save lives.
job of countering bioterrorism now has a potent weapon in BASIS,
the Biological Aerosol Sentry and Information System, which won
a 2003 R&D 100 Award. Designed by a team of researchers from
Lawrence Livermore and Los Alamos national laboratories, BASIS
is a detect-to-treat technology. That is, it’s designed to
detect and locate an aerosol release of a biothreat organism quickly
and accurately enough for an effective response. For example, the
survival rate from exposure to the anthrax bacterium is high when
antibiotic therapy can be administered before symptoms appear,
but after symptoms manifest, the survival rate diminishes significantly.
collects air samples at well-defined locations and at specified
time intervals to help determine both the time and place of the
release. Its mobile field laboratory rapidly tests samples for
evidence of potentially lethal bacteria and viruses. Safeguards
built into the system ensure a sample’s integrity.
Aerosol releases of bacteria or viruses tend to quickly become
diluted as their distance from the release site increases. BASIS
is designed with extremely high sensitivity for detecting the most
likely threat pathogens. By identifying a pathogen within hours,
BASIS allows medical response units to mobilize while law-enforcement
agencies begin the search for terrorists.
Key Goal Is No False Alarms
to Dennis Imbro, the principal investigator for Livermore’s
BASIS effort, false alarms have the potential to cause immense
disruptions and panic among civilians. Therefore, a primary goal
in developing BASIS was to achieve a virtually zero rate of false-positive
detections. To date, no false-positive events have been generated
by deployed systems.
BASIS is designed for indoor or outdoor use at high-visibility events
or around likely terrorist targets. In 2001, the technology was successfully
tested with live microbes inside a sealed chamber at the U.S. Army’s
Dugway Proving Ground. BASIS was first deployed in the month following
the September 11 terrorist attacks. It was also deployed in Salt
Lake City, Utah, for the 2002 Winter Olympic Games. During the Olympics,
BASIS operated for 35 days at sports venues, urban areas, and transportation
hubs. In all, 2,200 air samples were analyzed.
BASIS was later deployed in Albuquerque during the summer of 2002
and in New York City for the first anniversary of 9/11. BioWatch,
a derivative of BASIS, is now deployed in major cities nationwide
under the auspices of the U.S. Department of Homeland Security. BioWatch
features elements of the BASIS technology but, instead of a mobile
laboratory, uses laboratories that are part of the federal Laboratory
Response Network operated by the Centers for Disease Control and
BASIS team (left to right): Mark Wagner, Evan Skowronski, Cheryl
Strout, Paula McCready, Julie Avila, Kris Montgomery, Linda
Danganan, Linda Ott, Jackie Cofield, Patsy Gilbert, Paul Sargis,
Virginia Montgomery, Tom Slezak, Dennis Imbro, Robert Johnson,
Rich Parker, and Bruce Henderer.
Field Lab Tests for Pathogens
BASIS includes three major components. Aerosol collection hardware
continually collects, time-stamps, and stores samples. A mobile field
laboratory analyzes DNA from the samples and can identify and characterize
a threat organism in less than half a day with a virtually zero false-alarm
rate. Software designed by the BASIS team controls and integrates
samplers, called distributed sampling units (DSUs), suction air through
filters that have microscopic-size pores and collect
any regional microbes onto the filters’ surface. DSUs can be
deployed indoors, for example, at sports arenas or airline terminals
or within heating and air-conditioning systems, and outdoors at airport
drop-off areas, urban commercial centers, bridges, tunnels—any
area with a significant threat of bioterrorism. DSUs are locked and
password-protected to prevent unauthorized access and to guarantee
the integrity of filters.
mobile field laboratory analyzes each filter, searching for DNA from
target pathogens—those organisms identified by
the CDC as high-priority threat agents. Inside the field lab, DNA
is amplified via the polymerase chain reaction (PCR), a quick, reliable
method for detecting DNA of specific microbes. Should a target pathogen
be present, PCR amplifies its DNA while ignoring DNA from other microbes.
a positive finding and identification of the organism, the laboratory
analyzes the target sample a second time. The characterization
is so precise that a microbe can often be identified down to the
strain level. The suspect DNA can then be sequenced to determine
if genetic engineering has, for example, increased a microbe’s
virulence or has in any way engendered drug resistance.
a positive identification has been confirmed, the field lab immediately
notifies the appropriate response agencies. The entire
process—from collecting samples to identifying a threat organism—typically
requires only 8 to 10 hours.
software package runs on a standard laptop computer. The software
is divided into two modules: the BASIS Operations Center
(BOC) control package and the Sample Management System (SMS) filter-tracking
package. The SMS uses bar codes to track filters at every point of
the operation—from preparing a filter to processing the final
results in the field laboratory. Each DSU can receive operational
parameters via shielded cable, radio frequency, or cellular modem
and can transmit them in real time to a BOC laptop.
BASIS is just one of a host of counterterrorism technologies and
systems being developed at the national laboratories. Its success
demonstrates that Livermore researchers are on the right track in
the fight against terrorism.
Key Words: BASIS (Biological Aerosol Sentry and Information System),
BioWatch, bioterrorism, homeland security, polymerase chain reaction
(PCR), R&D 100 Award.
For further information contact Dennis Imbro (925) 423-0220 (firstname.lastname@example.org).
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