Foot-and-mouth disease: A conversation over an unlikely outbreak

However, the U.S. has not faced an outbreak since 1929 thanks to collaborative risk management and biosecurity efforts industry-wide.

Danielle Schlegel

FMD is highly contagious and affects cloven animals such as swine and bovines, which could potentially spark a severe deficit of meat production in the event of a widespread outbreak.

Economic impacts of an FMD outbreak

Production losses due to depopulation of exposed animals and additional losses thereafter due to limited production after an outbreak in affected facilities
Disease eradication costs including quarantine enforcement, euthanizing and disposing of infected animals, compensation to producers for destroyed animals and disinfected affected premises
Trade losses would be felt for months or even years due to the U.S. losing FMD-free status in the eyes of the World Organization for Animal Health (OIE), the global overseeing body that ensures transparency of diseases such as FMD.

Clinical signs of an FMD infection are most often very overt and dramatic, and often appear in infected animals within two to 14 days of exposure.

Animals that are suspect of an FMD infection should be immediately reported to a veterinarian, state or federal animal disease control officials, or a county agriculture agent. However, it should be noted that FMD is not a public health concern and does not impact food safety or humans.

Clinical signs of FMD in cattle

Blisters and erosions in and around the mouth, between the hooves and on teats
Excessive stringy or foamy salivation and drooling
Lameness
Prolonged high fever
Decreased appetite due to painful lesions in the mouth
Weight loss
Low conception rates
Abortion
Increased death rates, especially in newborn animals
Reluctance to move or stand

Transmission of the virus can occur rapidly through bodily secretions, direct contact and via airborne mechanisms. The virus spreads widely throughout an infected animal’s body and has been isolated from various parts of the animal, including blood, milk, oral secretions, nasal secretions and muscle tissue.

As such, beef-producing countries globally have implemented strict housing, biosecurity, health and transportation guidelines mandated by the OIE.

As Dr. Ernest Hovingh, extension veterinarian and senior research associate at Penn State University’s Department of Veterinary and Biomedical Sciences, notes that countries designated as not “FMD-free” by the OIE often have zones that are declared by the OIE to be “FMD-free,” which is a part of global efforts to reduce infection both within and across country borders.

Aimed at reducing the risk of spreading the virus to other countries, there are strict and specific recommendations for the importing of cloven animals and products including live animals, fresh meat, meat product and embryos, he adds.

FMD from raw beef

The recent trade policies enacted in agreements between Brazil and the U.S. to import raw beef products sourced from FMD-free zones in Brazil has prompted concern for the introduction of FMD into the U.S.

As mentioned, FMD is a virus that can survive in fresh meat, so the possibility exists that the virus can cross borders by way of raw meat products. However, an infection from a strain carried into a country via raw meat is unlikely, as Sanderson notes, because meat is not fed to cattle in the U.S., and the virus could not be inhaled off of raw products.

“The virus transmission pathway for commercially imported fresh beef from Brazil or any country is not likely because that meat is going to come in and is going to go through ordinary marketing channels, then be consumed by consumers,” Sanderson notes.

“The only real path would be the rare incidence where somebody buys that meat, and happens to have a pig or two and feeds them the scraps – which assumes that the FMD survived cooking, which is not likely. It’s just not likely.”

Hovingh also reiterates Sanderson’s point by citing regulations that prohibit animal proteins derived from mammalian tissues being fed to ruminants as a result of a transmission risk minimization focused on bovine spongiform encephalopathy “substantially reduces, if not eliminates, the risk of establishing an FMD infection in ruminants from meat possibly contaminated with FMD.”

Citing global and federal biosecurity policies, Hovingh also reiterates that there are stringent biosecurity policies in place that explicitly requires strict housing, biosecurity, health, transportation, pre- and post-mortem inspections at approved slaughter facilities, omission of the head in consigned meat products which includes the pharynx, tongue and associated lymph nodes, and vaccination guidelines when appropriate.

Additionally, Hovingh notes that due to the low stability in FMD virus strains, it is highly unlikely that beef produced in FMD-infected countries could export consumer-usable products that have viable FMD strains based on the global trade regulations and policies in place between respective countries.

Outbreak impact and management

Most notably, the U.K. FMD outbreak in 2001 affected approximately 10 million animals. While economic estimates vary due to the complex factors, both indirect and direct, that are considered when considering economic impact, most sources that have researched this crisis fall around an approximated estimate of $14 billion.

Sanderson says that the U.S. has taken note from the U.K. outbreak to mold current disease management strategies in the states.

“The paradigm for how we would handle an outbreak has changed a lot in the last six or seven years,” Sanderson says. “Part of that is learning from the U.K. outbreak in 2001.”

Logistically speaking, it can be difficult to depopulate an impacted herd in attempts to get ahead of an FMD outbreak, especially in large operations, but that can be the best option from a disease control standpoint, Sanderson says.

However, it certainly would not be feasible for the whole industry. While he also notes that the vaccines that are available today work fairly well against FMD, producers would only see a maximum of six months’ immunity out of a vaccine directed at a specific strain due to the nature of the virus.

“There are seven different types of FMD and, within those seven, there are about 62 different subtypes,” Sanderson says. “There’s no cross protection among any of the strains. You have to wait until you know which strain is present, and then a vaccine is built for that strain/subtype.”

Sanderson predicts that the future of FMD management and mitigation for any future outbreaks in the U.S. will be centered around vaccine programs, albeit a management strategy that is not yet viable because we don’t currently have the capacity to meet the demand for an industry-wide vaccine program.

In the interim, collaborative initiatives are in place to ensure industry-wide preparedness and risk management against FMD that Sanderson is a part of.

Alongside himself and another representative from KSU’s Department of Veterinary Medicine, Iowa State University’s Center for Food Security and Public Health, National Cattlemen’s Beef Association and the USDA–APHIS Cattle Health Program have teamed up to form Secure Beef Supply.

Secure Beef Supply plans aim to “maintain business continuity for beef producers and processors during an FMD outbreak, minimize disease spread and assure a continuous supply of beef products to consumers” by way of “developing processes and procedures that focus on FMD preparedness, response and recovery of the feedlot and processing industries” as well as any associated entities (Secure Beef Supply).

While this program is in its infancy, Sanderson envisions this initiative to be a resource for the entire industry moving forward. Regardless, biosecurity and risk management is important to anyone who is a part of the industry, whether it is FMD or other economically devastating diseases.

“Irrespective of Brazilian beef, there is some risk that FMD could get introduced to this country,” Sanderson concludes. “The things that are worth doing are general biosecurity management practices, [and] it pays off for other things.

If FMD never comes, there are some good, general, basic biosecurity things that pay off for [diseases such as] BVD and salmonella. Producers can justify those biosecurity risk management practices regardless of the disease.”

PHOTO: Regulations that prohibit ruminants being fed mammal proteins substantially reduce, if not eliminate, many risks of establishing an FMD infection. Staff photo.