Physician assertiveness will prevent outbreaks of illness. (Security Beat).

The ability to prevent people from getting ill after a biological or chemical agent attack does not just depend on the types of detectors installed in cities, said an expert. Just as important are "disease surveillance and integrated communication within the medical system," said Erik Henchal, the commander of the U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID).

"Within the medical community, what we say is, 'Don't depend upon environmental detection, pay attention to disease surveillance, because we believe that detectors may not work, may not be able to detect the limited use of a biological warfare agent,'" he told reporters at a breakfast meeting in Washington, D.C. "What we have to then pay attention to is; 'Are we starting to get unusual outbreaks of disease?'"

For example, when a physician notes the existence of an unusual pneumonia or respiratory disease, he should not simply expect that it is an anomaly in his locality. He can actively seek out information and communicate with other clinics that may have the same experience.

"Somebody has got to do the detective work to put that together," Henchal said. "The laboratory's role at that point is to take those medical specimens and...use confirmatory diagostics to try" to determine the presence of an agent and "confirm it to a level of high confidence."

He said that as far as detectors are concerned, those would have to be "where the cloud is, wherever it is that the agent is being dispersed." He said that a lot of the original detectors, especially for the military, were built on the concept of a "big Soviet-style air strike spreading a cloud of disease."

A more modern scenario "may be six North Africans making ricin in an apartment and going after individual targets," he noted. "Those scenarios are going to be much more difficult to detect if we rely on environmental screening as our trigger to future analysis," Henchal said.