The state of biodefense: I

Once a year a select group of scientists and engineers gathers at Dugway Proving Ground, a salt flat in the Utah desert sixty-five km from the nearest traffic light. They are invited by the U.S. Defense Department’s Joint Program Office for Biological Defense to take part in a competition in which the systems for detecting biological warfare agents they have developed are field-tested. With the growing concern about terrorists using biological and chemical agents, this competition has an added urgency. The IEEE Spectrum’s Christopher Aston writes that shortly before the trial gets under way, the competitors make final adjustments to their devices and then retire to trailers nearly a kilometer away. Moments later, an aerosol cloud containing spores of Bacillus globigii is released into the air about ninety meters from the devices. This harmless bacterium simulates a real bioagent such as Bacillus anthracis, the germ that causes anthrax. As the aerosol cloud passes, the devices collect and prepare air samples, and then feed them through diagnostic tests, looking for the bioagents by using highly specific molecular interactions. High-tech versions of the proverbial coalminer’s canary, these devices are designed to determine the type and concentration of the agent within minutes, enough time to let soldiers on the battlefield don protective gear. Data are sent to a remote sensing post by wireless modem. At the trial’s conclusion, the biodetectors are rated on how well and how quickly they identified the surrogate agent, as well as on their ruggedness, power consumption, weight, size, reliability, and safety.

The ultimate goal of the Dugway trials, and of more controlled experiments in the laboratory, is to develop portable, fully automatic, remote sensing systems that can detect a variety of known and novel biological agents before troops on the battlefield are exposed. The dream solution, even if it is years off, is a wristwatch-sized biodetector capable of rapid detection, rapid diagnostics, and, potentially, rapid treatment. Note that DHS’s Directorate of Science and Technology is toying with the idea of equipping cellular phones with miniaturized chemical detectors — in fact, turning tens of millions of Americans into walking chemical-agent sensors. If such phones are also equipped with GPS capabilities, the authorities would receive instanteneous, real-time alert of a chemical relase — and the precise location of this release.

Experts take the threat of biological war seriously. In wargames of a fictional attack on Oklahoma City, it was predicted that an infectious agent such as smallpox could spread to three million people throughout the continental United States within twelve weeks of an attack. U.S. intelligence has identified twenty-four nations suspected of developing or harboring biological weapons today. The United States itself ran an extensive biowarfare R&D program, before it was abruptly halted by President Richard Nixon in 1969.

Existing detection systems are typically fairly large and not very accurate, and require humans to operate them. A U.S. Army’s mobile lab, for example, is housed in a Humvee and manned by four technicians. An alternative is the helicopter-mounted unit made by Orlando, Florida-­based Schwartz Electro-Optics. The helicopter-mounted unit can, from a distance of fifty km, distinguish naturally occurring clouds from the cigar-shaped plume emitted from a moving object, the telltale sign of a biowarfare attack. It cannot identify specific agents, however. The detectors now under development fall into three categories:

* Biochemical systems, which detect a DNA sequence or protein unique to the bioagent through its interaction with a test molecule

* Biological tissue-based systems, in which a bioagent or biotoxin affects live mammalian cells, causing them to undergo some measurable response

* Chemical mass spectrometry systems, which work by breaking down a sample into its component amino acids and then comparing their weights to those of known bioagents and other molecules

These and related system will be discussed in “The state of biodefense: II” in the Monday issue of HSDW.