Imagine that a small group of terrorists deliberately infect themselves with smallpox and then walk around London, spreading it to the populace. How much could the terrible disease proliferate before the world realized something was amiss?
This unsettling question is at the heart of new computer model showing how a bioterrorism attack in one city could quickly become the world’s problem. Scientists started off with the hypothetical release of smallpox in London, New York, Paris and other major cities, then simulated how travelers would carry the virus to a host of other countries. Their conclusion: In the best-case scenario, smallpox could spread to two to four nations before doctors managed to diagnose it. Still ahead would lie the monumental task of quarantining the infected, distributing vaccines and tracing the source of the outbreak.
Previous research into bioterrorism have indicated that Western cities, with their protocols and vaccines, are pretty well prepared to handle a biological attack, says Alessandro Vespignani, a computer and health-sciences professor at Boston’s Northeastern University. But in a paper in this month’s Scientific Reports (don’t worry, it was vetted for international-security issues), he and his fellow researchers argue that the assumption of local readiness is missing the big picture. “The problem is that most of those studies don’t consider the global dimensions of the event,” Vespignani says. “Before you even realize there is an outbreak, it might already be in other places. That changes the game.”