Getting the word out about foot-and-mouth disease (FMD) will help the United States better prepare for the potential disease disaster.

Even with the best emergency disease preparedness plans, foreign animal disease outbreaks still occur. That's why the U.S. Department of Agriculture (USDA) decided to team up with its commodity industry partners last month to stage an FMD media day at its Animal and Plant Health Inspection Service (APHIS) offices at Riverdale, MD.

Forging closer ties will enhance effective disease prevention strategies, says John Clifford, DVM, deputy administrator for APHIS' Veterinary Services.

APHIS has been working behind the scenes with livestock and dairy stakeholder groups since 2001 in defining and refining its emergency response plans for FMD. But officials from both sides came to the realization that a program needs to be effectively communicated to succeed.

“We rely on you to help the public understand and relay technical information to them. Good communication helps all of us: helping explain to producers what to do during a disease emergency, and helping the public and our trading partners understand that this disease can affect the health of our nation's herd and export of our products,” Clifford adds.

APHIS has learned firsthand about the public's needs for simple explanations of complex animal disease information. A good example is the bovine spongiform encephalopathy (BSE) situation. The federal agency found that explaining the cause of the disease was very complicated. APHIS fielded about 10,000 calls over the last half-dozen years, says Ed Curlett, APHIS director of Public Affairs. Still, today about 20% of consumers surveyed confuse BSE with FMD. BSE, or Mad Cow Disease, is a chronic, brain-wasting disease found mainly in cattle and sheep.

In contrast, FMD is much more pervasive and devastating, says Jose Diez, DVM, associate deputy administrator for APHIS' Emergency Management and Diagnostics. The virus affects all cloven-hoofed animals.

“The virus is excreted in very large amounts, and it only takes a small amount to infect animals. It also has a short incubation period, as little as 3-5 days. If left unchecked, an FMD break in the United States would spread very rapidly and cost the country billions and billions of dollars,” he says.

For example, the FMD outbreak in the United Kingdom affected about 10 million animals at an estimated cost of $17.4 billion. The small FMD break there in 2007 cost $20 million/week.

California Study of FMD

APHIS and the California Department of Food and Agriculture conducted a study involving a “mock outbreak” of FMD in the state's large dairy industry, says Diez. Accumulating the cost of eradication, production losses and trade restrictions, APHIS pegged the direct cost of the disease at up to $4.8 billion. Losses to packers and processors were up to $2.6 billion. And trade losses could be up to $6 billion, because countries would stop purchases the moment FMD was identified, and products could only be sold to countries that currently have FMD.

“Because the disease occurs in about two-thirds of the world, there is always a chance of an accidental or intentional introduction,” Diez stresses. Many countries have learned to live with FMD, but USDA's policy is to stamp it out.

APHIS officials agree that even though the United States has been free of FMD since 1929, it would be a big mistake to assume a false sense of security.

To minimize the risk of FMD, the United States relies on its import regulations, point-of-entry surveillance, customs and border inspections and trade restrictions with FMD-affected nations.

Foreign Animal Disease Investigations

APHIS also conducts an average of 400 foreign animal disease investigations annually in the United States, mainly looking for vesicular-type lesions that could mimic FMD, says Jon Zack, DVM, Preparedness and Incident coordinator for APHIS' Emergency Management and Diagnostics. Last year, there were about 245 vesicular disease investigations.

For the swine industry, vesicular stomatitis, which sporadically affects livestock and horses in the western United States, appears somewhat similar to FMD. The FMD virus produces vesicles in the mouth, hooves, on the udder and teats.

Zack observes: “FMD is unique in that it is the most highly contagious disease in cloven-hoofed animals. FMD is not contagious to humans. All secretions are contagious, and the virus may be present in milk and semen for up to four days before clinical signs are seen. The virus infects susceptible animals orally, especially swine, and by respiratory tract, especially cattle.” Cattle express high susceptibility to the virus and readily react to it.

“Pigs are the amplifiers; if they get FMD, then they can replicate it and release air from their lungs through their nose and mouth into the air, and actually create a plume of virus that can spread down the road, depending on weather conditions,” he states.

Sheep tend not to show as significant lesions when infected with FMD, posing an unknown threat of disease spread when moved interstate.

“For FMD, it is clear that it is a devastating disease production-wise, but it is not one of those diseases that causes severe mortality in adult animals. Death rate is more common in young stock suffering from myocarditis (heart lesions) or failure to thrive from mouth lesions,” Zack says.

The other bad thing about FMD is the virus features seven serotypes and about 60 subtypes, he says. The problem is that current FMD vaccines don't cover all of the serotypes.

“The USDA and Department of Homeland Security are working hard to develop the next generation of FMD vaccines, which will be highly effective, provide rapid onset of immunity, stop virus shedding, and are effective against multiple serotypes.” Currently, FMD vaccines do not protect against multiple serotypes and subtypes.