Return to TFB Main Page
Return to Current Edition
Texas Agriculture Archive

March 19, 2004

Rapid FMD detection test in works

By Lana Robinson
Field Editor

The implications of foreign animal disease are serious. Just ask cattle producers, whose industry recently reacted to the first case of BSE (Bovine Spongiform Encephalopathy) found in the United States. Thanks to preparedness, the industry weathered the storm and maintained public confidence in the safety of U.S. beef.

A new initiative to improve the nation's ability to respond in the event that a foreign animal disease, such as foot-and-mouth (FMD), were to arrive on American soil, is planned for Texas this spring. The U.S. Department of Agriculture and the Texas A&M University College of Veterinary Medicine, working cooperatively, will be testing cattle for FMD and hogs for classical swine fever with new assays to determine the accuracy of the tests in disease-free animals.

Dan Dierschke, Texas Farm Bureau District 8 director, who attended a meeting outlining the program, emphasized, "The main point is it's not looking for disease, but rather trying to determine the accuracy of the test. This is a test on one particular disease, but if the process works, it may be expanded to other diseases. If it all works out, it will be a quantum leap."

The new experimental testing procedures that will be evaluated use "real time" polymerase chain-reaction technology to identify genetic material specific for the viruses that cause foot-and-mouth and classical swine fever. The United States is currently free of these diseases.

"No active virus is going to be involved. We don't want to have anybody upset thinking this might require the introduction of disease," said Dierschke. "Presumptive results are available in less than one hour."

Dierschke said the new, rapid tests could be performed in the field, enabling officials to quickly detect and impose a quarantine to stop massive spread in the event of a disease outbreak.

Currently, foot-and-mouth testing may only be performed at the U.S. Plum Island Animal Disease Center in New York, a high-security biocontainment facility. The usual method of confirming foot-and-mouth includes virus isolation–a procedure that, while accurate, may take up to a week to obtain results plus the time required to ship samples to Plum Island. In the interim, regulators and operators are left in a state of uncertainty.

A 2001 foot-and-mouth outbreak in the United Kingdom resulted in an estimated $4.9 billion (U.S. dollars) loss in its agriculture industry. A similar percentage income lost for the agricultural industry in the United States during 2001 would have amounted to $9 billion, researchers say, because of export market losses and eradication expenses.

"I think the real key is this is getting ahead of the problem before it occurs. It allows us to set up a response with lead time and fully test it without panic. It works much like the issues management team that was set up by the Texas Beef Council," said Dierschke, who is TFB's representative on the TBC board. "That really paid off in December 23 [2003], when the BSE detection was announced. In my mind, this is even a more sophisticated approach."

Another goal of the test, Dierschke explained, is to ascertain why polymerase chain reaction-based tests sometimes yield positive results when the sought-form disease is not present. One explanation is that positive reactions may be caused by non-disease organisms in the environment that have similar genetic material to the disease being tested. Texas was chosen for the tests because organisms that may interfere with the new tests are expected to be very uncommon and related to specific geographic locations and environmental conditions.

The U.S. Department of Agriculture-Agriculture Research Service funded the $750,000 study through the U.S. Department of Homeland Security. Scientists from ARS, the USDA-Animal and Plant Health Inspection Service and Texas A&M are collaborating.

"The potential threat from foreign animal diseases gives great urgency for this kind of development and evaluation of new diagnostic tests," said Dierschke. "Texas has long been a leader in the cattle business, so we are proud to see this bold step toward reducing the likelihood that an outbreak of foot-and-mouth would be economically devastating to our nation."