Grand Challenge: Confirming the Source and Motive of a Future Biological Attack

If the United States was the victim of a biological weapon, how would the government determine the source of the attack?

Not being able to answer that question is keeping leaders in the field of biosecurity up at night, experts said during a panel discussion at AAAS.

The response to a hypothetical bioterror attack would vary dramatically based on the source and motive for the attack. With such high stakes, the implications of misattribution could be extremely damaging to U.S. interests. “One of the grandest challenges of this world in biosecurity is discerning to a reasonable degree of certainty, if an event is it deliberate, accident, or natural,” said Chris Bidwell, a U.S. Navy commander currently assigned to the U.S. Defense Threat Reduction Agency and an adjunct professor of international relations at Georgetown University.

“I really do worry about developing and validating sufficient science so that when the call comes, that we have the tools in place,” said Randy Murch, associate director of research program development at Virginia Tech’s Research Center in Arlington, Virginia. “They have to be in place before the fact, and validated, so that when the call comes from the White House, U.S. government agency, or actually world leaders asking for U.S. assistance, that we can provide the kind of science which results in the information necessary to inform a proper decision.”

Bidwell and Murch, as well as Kristin Omberg, deputy division leader of the Decisions Application Division at Los Alamos National Laboratory (LANL), spoke 1 October at an event in the AAAS Auditorium. “Biosecurity: Confronting Existent and Emerging Unknowns” was the first discussion in the three-part “Science and Society: Global Challenges” series sponsored by the AAAS Office of Government Relations, the American Chemical Society, and Georgetown University’s Program on Science in the Public Interest. The discussion was moderated by NPR science correspondent David Kestenbaum.

Murch said that the United States began to lay the foundation of capabilities for the forensic investigation of bioterror attacks in 1996, with the science and capabilities expanding rapidly following the anthrax attacks of 2001. When members of the media and the U.S. Senate received letters contaminated with anthrax spores, the United States first started thinking seriously about the possibility of doing routine bio-detection in urban areas, Omberg said.

“In the run-up to the war with Iraq, there was a lot of concern because there was a legitimate question as to whether or not Iraq had chemical and biological weapons and would be willing to use them once we gave Saddam Hussein the ultimatum to leave the country,” she said. “And so that was when we started looking nationally at bio-detection.”

That interest in bio-detection led to the development of the BioWatch Program, a detection system by the Department of Homeland Security that monitors for potential airborne bioterror attacks. “If you think about what it takes to respond to an attack, it’s a tremendous drain on resources and it takes a lot of planning and a lot of preparation to be able to do that well,” explained Omberg, LANL project leader of BioWatch. “It [BioWatch] buys you time to prepare and figure out what you’re going to do.”

Lawmakers have expressed skepticism over BioWatch, specifically concerning false alarms caused by naturally occurring pathogens. Murch recalled learning of an alert triggered by BioWatch. “My first response was, what, dead rabbit near the sensor?” he said. “And it was a tularemia alert and it was a dead rabbit near the sensor.”

“Certainly early detection is important but you have to put things in context,” Murch said. “On the one hand, the technology is a very good technology and it’s tuned to alert on certain pathogens with certain sensitivity. But on the other hand, those can come from the environment. So then you have to investigate, you have to apply resources to determine where did it come from and how did it manifest before it can be determined whether what caused the alert was a natural or deliberate event.”

Omberg rejected the suggestion that BioWatch has produced false alarms. “It doesn’t tend to pick things up that aren’t there,” she said. “It’s just that it wasn’t due to a terrorist attack.”

However, the attribution of bioterror attacks remains extremely challenging because microbes mutate, Omberg said. “What we characterize today may not be what’s used and even what’s used might not be what we can characterize out of that three days later.”

“What we’re looking at is a snapshot in time,” Murch said. “It’s not so much though with some other kinds of forensic evidence.”

Meanwhile, before scientists can determine the source of the attack, the press is already covering it, Bidwell said. “You’ll be swimming upstream against a public opinion wave that is already starting to collect its own evidence and form opinions as to what happened. This, in turn, puts additional pressure on policymakers.”

Kestenbaum recalled while covering the anthrax attacks, reporters were told that anthrax samples had been identified that matched those found in the letters—but the use of the word “match” was later criticized for being imprecise.

Murch agreed that in that instance, “match” was inappropriate. There was a very close similarity between the samples and the FBI had gathered about as many specimens as were available at the time, he said, “but one of the great difficulties in this kind of forensic science is your base of known specimens is relatively limited.”

Moreover, Bidwell, a former trial lawyer, explained: “If you’re trying to use forensics to prove an attack came from outside the United States, you’re going to have a hard time explaining where the samples originated from, making them inadequate for attribution purposes.”

In a bioterror attack, scientists would need to arm the policymakers who would determine the U.S. response with an understanding of the complex science involved. “Just like with a jury, as evidence gets presented, you’re going to be explaining science to a policymaker who may not have a science degree,” Bidwell said. “The science actually doesn’t have to be as perfect as it has to be plausible and understandable.”

When it comes to BioWatch, “we have not had an attack so it has not done its benefit yet,” Kestenbaum said to Omberg. “Thankfully, you have never had a chance to shine.”

“God willing,” she replied, “we never will.”


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