September 15, 2003


 'We're looking for zebras now'

Posted Sept. 1, 2003


Everything changed on 9/11. America's sense of security came crashing down with the World Trade Center and the airliners that struck the Pentagon and exploded in a Pennsylvania field.

During the Emergency Preparedness and Response track at the AVMA Annual Convention, July 22, U.S. Air Force Reserve Brig. Gen. Richard B. Ford talked about the twin threats of biologic and chemical terrorism and the need for veterinarians to remain vigilant against attack.

For years, the U.S. government and military planners were acutely aware of terrorism, and with good reason. During the 1990s, there were attacks on the World Trade Center, spectators at Atlanta Olympic Park, the federal building in Oklahoma City, and the Khobar Towers in Saudi Arabia.

The Department of Defense invested heavily to protect American soldiers deployed in forward areas from chemical and biological attacks. But 9/11 and a few anthrax-laced letters started the military down a different path.

Dr. Ford is a professor at North Carolina State University College of Veterinary Medicine and also works in the Office of the U.S. Surgeon General. He explained that, in terms of dollars, conventional warfare is the most expensive, followed by nuclear, chemical, and biological warfare.

Biologic weapons are "the poor man's nuclear bomb," because they're cheap to make and can be devastating in terms of killing power. Biologic weapons also are preferable because it is difficult to detect biologic agents and impossible to totally defend large areas and large populations from attack; thus, they generate fear.

Most of the agents that would be used in a biologic attack, according to the DOD and national Centers for Disease Control and Prevention, are animal pathogens, such as Bacillus anthracis, Yersinia pestis, and Francisella tularensis, Dr. Ford noted.

Dr. Ford discussed at length the infections that resulted from the anthrax-laced letters mailed to news media outlets and two U.S. senators shortly after 9/11. Five people died, and 11 people were infected but recovered, thanks to the use of aggressive antimicrobial treatment.

Dr. Ford pointed out that not enough anthrax vaccines exist at this time to protect the entire U.S. population, should the need arise.

The most frightening biologic agent is smallpox virus. After the World Health Organization declared smallpox a "nondisease" in 1971, only two places were known to house the virus—one in the United States and the other in Russia.

Dr. Ford said that Soviet scientists had produced large quantities of the virus. But since the dissolution of the Soviet Union, some virus samples are not accounted for. "We know where our smallpox virus is," he said. "But we don't know where all of Russia's is."

Most troubling is that smallpox vaccinations ended more than 20 years ago, so a huge portion of the population is susceptible to the deadly virus. Several U.S. medical institutions have adamantly refused to vaccinate their personnel, fearing that the potential health risks resulting from vaccination outweigh the benefits.

"It's going to take a wreck at the intersection before they put up a red light," Dr. Ford predicted. "We're going to have to have a crisis in this country before we actively move forward. That's the way we respond."

Attacks on U.S. agriculture are also a major threat. "Agroterrorism, while not having a direct impact on health, has a huge economic impact on the United States, and that is an indirect public health issue," Dr. Ford said.

He explained that trillions of dollars are tied up in U.S. agriculture. For instance, agriculture is the nation's largest employer.

What would happen, Dr. Ford asked, if the foot-and-mouth virus were introduced in the United States? A researcher at Colorado State University projected that placing a single test tube of tongue scrapings from an FMD-infected animal into a water trough at a Colorado sale barn would disseminate the virus to 16 states in three days.

The principle in diagnostic medicine that goes "When you hear hoofbeats in Central Park, don't go looking for zebras"—meaning look for the obvious, not an exotic virus—no longer applies in today's world of biosurveillance. We're looking for zebras now, according to Dr. Ford.

Dr. Ford challenged veterinarians to be suspicious of every unusual case they see, saying that, despite the billions of dollars appropriated for biosurveillance, it still comes down to the clinicians.

"We've got lots of issues in our profession and in the human medical profession where the surveillance comes down to the individual," Dr. Ford said. "And I think that's our role as clinician, whether you're in food animal medicine, equine, or small animal. Awareness is a key issue."