"In the case of foot-and-mouth disease it takes little scientific training," Sen. Pat Roberts, a Kansas Republican and chairman of the Intelligence Committee, told the Agriculture Committee hearing.

"You put a handkerchief under a diseased animal in Afghanistan, put it in a zip-lock bag, put it in your suitcase, come to the United States and drop it in any one of our feed lots. And we're in a lot of trouble."

Other animal diseases such as Rift Valley fever in Africa, Nipah virus in Asia, and avian influenza are significant threats because of their contagious nature and the fact that they can cause death in humans, James Roth, director of the center for food security and public health at Iowa State University, testified before the hearing.

U.S. agricultural exports are seen at around $59 billion in 2005, making it the third-largest export sales year, Deputy Agriculture Secretary Chuck Conner said. The U.S. food system contributes $1.24 trillion, or more than 12 percent, to gross domestic product and employs 18 percent of the U.S. work force.

Food products flow quickly via interstate commerce, making the sector particularly vulnerable. "Diseases and pathogens do not acknowledge state or national borders. The threat to agriculture is very real," Conner said.

MAD COW EXPOSES FLAW?

Confusion over confirming a second U.S. case of mad cow disease recently may have revealed a flaw in the system, Senate Agriculture Committee chairman Saxby Chambliss said.

"I am concerned that since the fact of Sept. 11 we have spent millions and millions of dollars on the issue of homeland security but yet we don't have a lab in the United States of America that's capable of making an instantaneous decision on BSE, which is a fairly common disease," Chambliss said.

Conner said the USDA decided to use Britain's Weybridge laboratory because it had more experience with the disease, although it conducted no tests that the USDA could not have done itself.

The animal tested positive for bovine spongiform encephalopathy or BSE in a rapid screening test in November, but was found free of the disease when retested. In June, USDA scientists reopened the case and tested again, using a third kind of technology which showed the 12-year-old cow was infected with the brain-wasting ailment.

More U.S. lab capacity for animal health research and disease diagnosis is needed, said Roth. Also needed are more veterinarians and experts to prepare for and respond to a foreign animal disease that could transfer to humans.

VOLUNTARY ACTION

To help companies safeguard U.S. food, the USDA has issued some voluntary guidelines. These include security guidelines for the livestock industry, meat processing plants and truckers transporting agricultural commodities to prevent contamination, Conner said.

The Department of Homeland Security is developing an agricultural forensics team to understand quickly who perpetrated an intentional event and provide information that can be used in court, said Maureen McCarthy, director of DHS's office of research and development.

John Lewis, deputy assistant director of the FBI's Counterterrorism Division, said the bureau had set up an agriculture intelligence working group and was reaching out to farmers, cattle ranchers, food producers and distributors.

"We know from the body of intelligence collected to date that al Qaeda is aware of our agriculture industry, along with other potential targets," he said.

By Sophie Walker

Copyright � 2005 Reuters Limited.