back to list

Some Fear Avian Flu Could Be Weaponized - 2005-03-09

Canada's Directorate of Strategic Intelligence has warned the Canadian federal government that avian influenza could be used as a weapon of bioterrorism and that military planners believe a naturally occurring flu pandemic may be imminent, the Canadian Press website reported. The warning was presented in an 8 December 2004 report recently released, entitled "Recent Human Outbreaks of Avian Influenza and Potential Biological Warfare Implications," which the website obtained through an Access to Information Act request. The 15-page report outlines in broad terms the methods that could be used to develop a man-made strain of influenza capable of triggering a human flu pandemic and asserts that laboratory culturing and selection could be used as a "potentially highly effective" method for developing a strain with enhanced virulence against humans and/or poultry. Many experts believe avian flu or another strain of influenza would be an especially effective tool for a bioterrorist, as it would be nondiscriminatory and as even a relatively small case could cause significant repercussions. "To me it's one of the most logical viruses to use. It doesn't have to be a really bad one to throw a huge wrench," Dr. Brian Ward, virologist at Montreal's McGill University, warned. Not all experts agree on that point, however. The news report quoted influenza expert Dr. Earl Brown, who characterized the strain as a "wimpy virus" that "doesn't persist in the environment very long [outside a host]" (CP). He added, "You have to infect people sort of straight away; otherwise it's going to die sitting around the environment" (CP). Perhaps the report's most significant passage concerns a method of transfer referred to as "passaging," whereby a viral strain is repeatedly cycled through generations of a species of animals or cell culture. The procedure can be used to ratchet up or dial down pathogenic virulence -- mild or severe -- depending on which offspring is used in the process, the report noted. That method can be highly unpredictable, however.

ANALYSIS. Despite assertions from some biological experts the influenza would be difficult to exploit as a biological weapon, the global circumstances surrounding the ever-growing avian flu virus suggest valid grounds for concern. Health officials have recently identified emerging trends in the virus that suggest it is not as detectable as previously thought. Further, new evidence surfacing in Vietnam and Thailand indicates that the frequency of human infections with the avian flu virus may be much higher than expected and that human transmission of the disease is a significant epidemiological factor in the proliferation of this disease in those countries. All these factors serve to support the gravity of the J2 report, but the extent to which terrorists can maintain and spread the disease remains unexplained. Still, evidence already noted suggests that primitive means and a host capable of lasting long enough to spread the disease in an advantageous locale may be the only prerequisites. Most biological agents must meet various criteria to be considered an effectual agent, chief among them the ability to jump the species barrier, transmit easily, and cause severe disease (CP). The avian flu has apparently satisfied these criteria. Nevertheless, there are some experts who contend that launching this type of agent would result in only short-lived damage. "There's a good change that you'd make something that just would burn out. It just wouldn't spread very well," Brown said (CP).