Cattle Enemy #1

The impact of a terrorist attack on U.S. agriculture could be devastating — and not just to the producer. Businesses such as farm suppliers, transportation, grocery stores, restaurants, equipment distributors, and, in the end, consumers, all would pay.

“Agriculture is considered by many to be the perfect target for bioterrorism,” says Radford Davis, Ames, IA. He's assistant professor of public health, Iowa State University (ISU) Department of Veterinary Microbiology and Preventive Medicine. “The threat of agroterrorism is real and the U.S. is now beginning to address it.”

The consensus is that the No.-1 terrorism threat to the U.S. agricultural economy — not just the cattle industry — is foot-and-mouth disease (FMD). This highly contagious viral disease doesn't affect humans but can devastate all animals with cloven hooves.

“An outbreak of FMD, either by intentional or accidental introduction, would bring our nation's economy to a virtual standstill,” agrees Terry Knowles, deputy director of the Kansas Bureau of Investigation.

FMD's economic impact

Davis cringes at the poor levels of biosecurity on the majority of farms and ranches today and at the vulnerability of the livestock industry to an exotic disease.

“The level of biosecurity across most of the industry guarantees unchallenged and unhindered access to the determined, patient terrorist,” he says.

If the U.S. cattle industry was hit with an FMD outbreak today, exercises conducted by USDA have calculated potential spread to 39 states with the need to depopulate up to 48 million animals.

Daryll E. Ray, University of Tennessee professor of agricultural policy, estimates the immediate direct impact of an FMD outbreak in the U.S. could approach $10 billion — equivalent to losing one-fourth the annual value of all net farm income.

The total direct and indirect impacts easily could be several times that amount, Ray says. Not included in this estimate is the cost to other susceptible animals such as swine, sheep and goats. His analysis also doesn't consider the costs of physically depopulating infected herds, disinfecting premises, quarantines and future surveillance.

“Two years ago, we were looking at the total direct and indirect costs of an FMD outbreak in Kansas to be in the range of $25 billion,” Knowles replies. “All you have to do is look at what happened in Great Britain. You can throw just about any number out there, and it wouldn't surprise me.”

The 2001 FMD outbreak in the United Kingdom resulted in the destruction of four million cattle. It's important to note the outbreak was deemed accidental. Estimates of the overall cost to the economy — primarily to the agriculture and tourism industries — ran as high as £30 billion ($48 billion US).

Whole new ballgame

Biological threats to agriculture represent a new challenge for Kansas law enforcement, Knowles says. “It's important we understand the threats, vulnerabilities, available resources and likely scenarios.”

To help with this understanding, several training sessions have been initiated. The Ford County, KS, sheriff's office hosted a regional seminar in Dodge City involving law enforcement officers, producers and feedlot operators in the west region.

“Officers were able to learn firsthand about the potential threats and the impact of a bioterrorism attack on livestock,” Knowles says. “In turn, there was a mutual understanding by livestock producers of the capabilities and resource limitations of law enforcement agencies.”

One of the major problems identified in training exercises designed to predict an FMD outbreak is how to effectively deal with the movement of livestock not affected by the outbreak. After all, more than 500 truckloads of cattle move through western Kansas every day.

“We've found stopping the movement of livestock requires contingency plans to handle unloading, feeding and caring for these cattle,” Knowles adds. “It would be an enormous logistical task.”

Complicated, virulent disease

An FMD outbreak in beef cattle would be further complicated in that dairy cattle, sheep and goats, bison, swine, elk, deer, moose and pronghorn are susceptible.

Furthermore, FMD experts say the disease virus can be disseminated via aerosol, direct contact with any body fluid from an infected animal, or contaminated meat and excrement.

Garry Brower, a Fort Hays State University associate professor, says a documented case shows that the “plume” exhaled by an FMD-afflicted cow can carry infectious levels of aerosolized FMD virus for 30 miles when humidity is 60% or more and the wind is non-turbulent.

“The virus will live in the soil for up to 28 days in winter and three days in summer,” he adds. “It will survive in urine for 39 days, dry feces for 14 days in summer, and in slurry or manure in holding ponds for six months in winter.”

A successful FMD attack needn't infect thousands of animals. It can spread aggressively from site to site. Just a small-scale attack on a few facilities could balloon into an epidemic spread by wind or the movement of animals and equipment.

To infect the largest number of animals at once, a terrorist may try to contaminate products, such as feed, that are distributed widely to the whole herd. One publicly disseminated tactic suggested by domestic ecoterrorists is to coat feathers with FMD agent, fill small bomblets and explode them over the target so they drift on the wind and contaminate a vast area.

Knowles says a potential “threat element” could go to the Internet and find ways to disseminate a disease like FMD “in a heartbeat.”

In a U.S. Army exercise several years ago, agents acting as potential customers infiltrated auction barns and pretended to infect livestock by spraying animals with bottles that contained water to simulate a solution of virus. They also successfully dropped handkerchiefs (to simulate a pathogen-soaked rag) into a livestock pen.

“Any number of methods would be highly effective in spreading diseases such as FMD,” Knowles says.

Terrorism's psychology

“An attack against animals or crops is generally viewed as more benign and less offensive than if humans fell dead from a direct assault,” Davis says. He adds agricultural terrorism isn't about killing animals but crippling an economy.

“To that end, agents foreign to U.S. livestock/poultry industries and crops would be preferred by terrorists,” he explains. “For animals, there are many foreign agents readily available in nature, from low-security laboratories, even from commercial sources, that require little effort or risk to smuggle into the U.S.”

Most foreign animal agents — like FMD — pose little or no human health risk, so the terrorist may feel some sense of security in handling and dispersing such pathogens. Once unleashed, an agroterrorism event may go unnoticed for weeks, making it nearly impossible to determine if the event was manmade or occurred naturally, says Rocco Casagrande. He's a director in the homeland defense practice at Abt Associates in Cambridge, MA, and served as a United Nations weapons inspector in Iraq.

“Groups with political, religious and criminal motivations, or devoted to a single issue, might turn to agroterrorism,” he says.

Casagrande also warns certain “ecoterrorist” groups might find the use of biological weapons like FMD particularly attractive.

“The most radical of these groups work toward the destruction of all agriculture because they believe it is a perversion of the natural order,” Casagrande says.

A biological attack targeting agriculture, Casagrande says, “…should be regarded as a high-consequence, high-probability event and receive the attention it deserves as a grave national security risk.”

Because a biological attack may be insidious at first, the need for effective infectious disease surveillance systems is obvious. Casagrande says terrorism involving a foreign animal disease (FAD) with zoonotic implications likely would be detected first by local or state health officials. But, veterinarians also have an important role in the surveillance for potential biological weapon agents by the prompt reporting of FADs, he says.

Concentration & contingencies

A major problem for the security of agricultural production is the geographical disbursement of unsecured environments. Another unique challenge is the concentration of livestock in confined locations and the high level of transportation and commingling that occurs.

“When you introduce a virus into an agricultural setting, since it is so concentrated, there would be a rapid spread,” says Peter Chalk, an agroterrorism expert from the Rand Corp.

Chalk calls agriculture the “glaring exception” in the U.S. terrorist contingency plan. He says, unlike the limited number of biological weapons against humans, there is a large menu of agroterrorism weapons.

Also, according to a new Congressional Research Service report, many veterinarians lack experience with FADs that are resilient and endemic in foreign countries. The report says the U.S. must develop a three-pronged strategy to preempt an attack or defend the nation against agroterrorism. This strategy should include deterrence and prevention, detection and response, and recovery and management of the crisis.

“FMD's threat to agriculture is real, and the U.S. is just now beginning to address it,” Davis says. “For example, how many livestock producers quarantine their new animals — the same animals that were just purchased at a crowded sale barn?”

He says it's time to begin taking this threat seriously.

“It's prudent for producers, veterinarians and other agricultural professionals to become familiar with the issues and details surrounding agroterrorism,” Davis says, “Then look at the contingencies and start making plans immediately.”

How does FMD spread?

Foot-and-mouth disease (FMD) is one of nature's most virulently contagious pathogens. FMD viruses can be spread by animals, people, or materials that bring the virus into physical contact with susceptible animals. An outbreak can occur when:

• People wearing contaminated clothes or footwear, or using contaminated equipment pass the virus to susceptible animals.

• Animals carrying the virus are introduced into susceptible herds.

• Contaminated facilities are used to hold susceptible animals.

• Raw or improperly cooked garbage containing infected meat or animal products is fed to susceptible animals.

• Contaminated vehicles are used to move susceptible animals. Vehicles should be thoroughly washed between shipments of animals to prevent transfer.

• Susceptible animals are exposed to materials such as hay, feedstuffs, hides, or biologics contaminated with the virus.

• Susceptible animals drink common source-contaminated water. Test water for bacterial, chemical or nutrient contamination. Prevent fecal and urine contamination.

• A susceptible cow is inseminated by semen from an infected bull. Buy semen, embryos or bulls from suppliers with control programs for infectious diseases.

Source: American Feed Industry Association Web site.