Foot and Mouth Disease diagnostic kit available
The U.S. Department of Homeland Security Science and Technology Directorate on June 19 announced the licensing of a rapid-response (three-hour) FMD diagnostic kit. The kit was developed in a team effort by federal agencies, academia and animal health industry scientists, and recently licensed by the U.S. Department of Agriculture Center for Veterinary Biologics.
This is the first licensed FMD diagnostic kit in the U.S. The diagnostic test can be used for cattle, swine, and sheep, and will be sold by Veterinary Medical Research and Development Inc., a U.S. manufacturer of veterinary diagnostics.
Dr. Dustin Oedekoven, State Veterinarian and Executive Secretary, South Dakota Animal Industry Board, said the DHS-funded Center of Excellence at Texas A&M has worked on a number of preparedness activities such as this new diagnostic test, and the mobile MCVI–a mobile veterinary health certificate app. The timing of the information exchange with certificates of veterinary inspection is also an important component of disease response and tracking.
“In tracing a number of diseases that impact the livestock industry, and most recently our TB investigation in Harding County, it is sometimes slow and labor-intensive to use the paper health certificates, even if we do have them scanned and organized in a database,” he said.
“This new FMD diagnostic test will decrease the amount of time required in diagnosing the disease in the event of an outbreak. This is significant because the currently approved blood tests already in use by USDA require an overnight incubation process. The new test has a 3 hour turnaround time,” Oedekoven said.
“The Center for Veterinary Biologics has now licensed this product and it could be used under state and federally-approved circumstances, such as in our federal foreign animal disease laboratory on Plum Island or in our National Animal Health Laboratory Network (NAHLN). Our state Animal Research and Diagnostic Lab at Brookings, SD is a NAHLN member lab. I supported the critically-needed renovation of the lab so that it could continue to provide these types of services for the livestock industry in our state and region, in the event we have a foreign animal disease outbreak,” he says.
“Animal health officials need to have the ability to quickly respond. There are many considerations in preparing and planning for an outbreak. If we were to have an outbreak in the U.S. there would likely be stop movement orders and quarantine, especially in the immediate area of the affected farm or ranch. We know that animals can incubate the disease and may not show clinical signs.
“Caution is crucial. Animals in high risk areas, such as those immediately adjacent to a quarantine area, may need to be tested before they could be moved out of that area for marketing, grazing, etc. Having rapid diagnostics as a tool would be very important for continuity of our livestock industry, so it’s good to see this new test licensed and ready for use, if we need it,” says Oedekoven.
Kathy Simmons, DVM and the National Cattlemen’s Beef Association’s Chief Veterinarian, says diagnostic tests of this type are used largely by regulatory officials to assist in establishing managed movement of non-infected or vaccinated animals in non-infected regions during an FMD outbreak. “Later, in the recovery phase of an FMD outbreak, where FMD vaccination is used, these tests are also utilized by regulatory officials to verify to trading partners that animals are FMD vaccinated and not FMD infected,” she says.
“This FMD diagnostic kit is not intended to serve as a primary surveillance tool. FMD Polymerase Chain Reaction (PCR) testing is currently the primary surveillance test. The benefit of the new FMD diagnostic kit over similar testing kits that are already present in the marketplace, is the test’s rapid response rate of three hours to yield results.”
This specific, sensitive diagnostic assay was developed and validated over a seven year period by scientists at Texas A&M University and the Institute for Infectious Animal Diseases in College Station, Texas (a DHS S&T Center of Excellence); DHS S&T’s Plum Island Animal Disease Center, USDA Animal and Plant Health Inspection Service Foreign Animal Disease Diagnostic Laboratory and USDA Agricultural Research Service Foreign Animal Disease Research Unit–through a Cooperative Research and Development Agreement with VMRD, Inc. Funding for development and validation was provided by the Agriculture Defense Branch of DHS S&T’s Chemical and Biological Defense Division and DHS S&T Office of University Programs. DHS S&T also granted an intellectual property license to VMRD, Inc. for the test. A patent application has been filed with the U.S. Patent and Trademark Office.
Foot and Mouth Disease (FMD) is caused by a virus that is highly contagious in cloven-hoofed animals, including cattle, pigs, sheep and goats. Countries that don’t have this disease are diligent to try to keep it out. Thus FMD has a significant impact on global livestock trade economics. There are extensive regulatory programs in the U.S. to facilitate identification of, response to, and control of this disease if it should ever appear in this country. With one in every nine Americans employed in agriculture or related industries, the effects of FMD outbreak in the U.S. would be devastating, and estimated at nearly $200 billion in lost revenue over 10 years across the affected industries. There are a number of ongoing research projects regarding FMD.
Producers in the U.S. are fearful that we may eventually see FMD in this country, so having the ability to quickly diagnose FMD would definitely benefit our livestock industry, according to Bill Bullard, R-CALF USA. Suspicious cases could be tested to see if the animal has FMD or something else. “There are other diseases that have similar symptoms, like vesicular stomatitis,” he explains.
“Having a rapid diagnostic test is good news. What is missing from this news, however, is the importance of more critical measures to ensure that we don’t introduce this virus into our U.S. livestock herds. There are some gaps in our security. There doesn’t appear to be any stop to USDA’s effort to continually expose us to more and more risks from more and more countries with FMD. Argentina, Brazil, and Namibia are just the most recent examples,” he says.
“This exposure is reckless, because we have already estimated the potential damage to our economy ($200 billion dollars) and it could literally devastate our U.S. cattle industry. We have more to lose than any other country because we are the largest producer of beef, and the largest consumer of beef. We have much more to lose than any developing country that has not made the investment we have made, to eradicate FMD from within our borders. We should not be exposing our livestock to an unnecessary and avoidable risk from these countries where the virus is known to be circulating.”
The only effective way to halt it is to shut commerce down around a large perimeter where the outbreak occurred and hope that the wind won’t blow it 40 miles. It can be carried by wind, birds, equipment, machinery, tires, and more he explains.
Even though there are some vaccines for FMD, there are problems with vaccination and we are not ready to be able to vaccinate to protect U.S. cattle.
“To protect livestock, you must have a vaccine that matches the specific type of virus that might occur in a particular area,” Bullard said.“On the one hand, we support efforts to improve our ability to contain FMD in the event of an inadvertent outbreak, but we are very concerned that we are not doing enough to ensure that we do not import this disease into our country.”
The South Korean outbreak was attributed to human transmission.
“One example of how we are increasing the likelihood of an outbreak in the U.S. is the fact we are moving our research facility from Plum Island, New York into the beef belt, to Manhattan, Kansas. We will be conducting live FMD virus research in the heart of our cattle country, which makes no sense to us, especially since the Plum Island research facility has had inadvertent releases of the FMD virus. That island is an isolated area, however, and the prevailing winds took the virus out across the Atlantic Ocean and it was not a problem,” Bullard said.
“When the National Academy of Sciences did one of their risk assessments of the Manhattan, Kansas proposal, their conclusion was that it was as likely as not that there would be an inadvertent release of the FMD virus within the 50-year expected life of the facility. That’s when USDA-APHIS and Homeland Security committed another billion or so dollars to beef it up. The most likely cause of an inadvertent release, however, is human error like what happened with the anthrax outbreak. It is unnecessarily risky to conduct this research right in the heart of beef country,” he said.
VACCINES FOR FMD
“Response plans for foreign animal diseases can be complex and vaccines are a tool we can eventually use,” says Oedekoven. “Vaccine technologies for FMD have improved, but we have a ways yet to go before we are able to use them as part of our response capabilities. There is a North American FMD vaccine bank which is shared (the supply, and the cost of maintaining the supply) by the U.S., Canada and Mexico. All three countries have been free of FMD for some time. This FMD vaccine bank does not have any shelf-ready vaccine, however. It just has the antigen,” says Oedekoven. It would take a while to have vaccine ready for use, even if we have the right strains of antigen for the type of FMD virus identified.
Simmons says cattle are usually considered the highest priority for emergency vaccine use with most strains of FMD. “If FMD is under control in cattle, then most FMD strains do not persist in other species. To induce immunity in the cattle population, all cattle in the affected region should receive two doses of normal potency FMD vaccine one month apart or a single dose of high potency FMD vaccine as soon as possible. In cattle, it is believed that 80% of the animals must be vaccinated to prevent transmission of the FMD virus in the herd. Administration of all FMD vaccine is controlled and directed by regulatory animal health officials. There are seven major serotypes of FMD virus and no significant cross-protection between serotypes. Conventional inactivated FMD vaccines have been used to vaccinate various species of livestock including cattle, sheep, goats, pigs and water buffalo,” she says.
Oedekoven says that in the event that one of the FMD viruses entered the U.S. we would first need to be able to identify it (there are7 major serotypes of FMD and several strains of each) and then hope we have the right antigen for that specific serotype in the vaccine bank. “Then we’d have to send that antigen overseas to be developed into a usable vaccine, and the vaccine shipped back to the U.S. This takes time, and during that time there could be continued exposure of more livestock and continued risk for further spread of the disease,” he explains.
“One thing we recognize now is that several countries during the last decade or so have successfully responded to an FMD outbreak using vaccination. There used to be hesitation about using vaccine as a tool in responding to an acute outbreak in an FMD- free country, partially out of concern for regaining OIE (the World Organization for Animal Health) designated free status. It appears, however, that several countries have actually regained their status more quickly by using vaccine in a strategic manner than some other countries that did not use vaccine. The attitude toward vaccine has shifted; there is more acceptance of vaccine as a tool,” he said.
“Now that we’ve made that shift, we need to do something about it. We don’t have a vaccine supply and we need one. Researchers continually develop new vaccine technologies, including FMD vaccines. One is a vectored vaccine, which uses a human adenovirus rather than the FMD live virus to induce immune response. This technology takes advantage of molecular biology, tricking the immune system into creating a defense against the FMD virus even though the body is not actually exposed to live virus,” he explains. This would be a safe vaccine because it could never transmit the disease, and vaccinated animals could be differentiated from affected animals with live animal tests.
“An FMD outbreak in the United States, whether of natural or intended origin, would have a devastating impact on the livestock industry as well as the economy,” Simmons said. “Therefore, it is of utmost importance for the defense of the U.S. agricultural sector to develop and maintain effective FMD vaccines that have potential to be produced in the U.S. and may be rapidly adapted to new FMD strains. Chemically inactivated FMD vaccines are effectively used to control FMD around the world; however, a major drawback in vaccine production is that large volumes (i.e., thousands of gallons) of high-titer infectious and fully virulent virus are handled with the associated risk of virus escape from manufacturing facilities,” she said.
“USDA-Agricultural Research Service (ARS) scientists at the Plum Island Animal Disease Center in New York have developed a novel FMD vaccine platform (FMD-LL3B3D) that will allow safe production of vaccines on the U.S. mainland. This vaccine can protect livestock against clinical disease, and prevent virus shedding and transmission, differentiate vaccinated from FMD-infected animals with testing and be readily adapted to new FMD strains. The FMD-LL3B3D vaccine still needs to be commercialized by a pharmaceutical company before it is available for widespread use. Similarly, work has been done to develop a novel adenovirus 5 vectored FMD vaccine. At present, conventional inactivated FMD vaccines are used to manage FMD outbreaks and to control the disease in endemic regions,” Simmons said.
“We are at a critical decision-making point in FMD preparedness for our livestock industry,” Oedekoven said. “We have some good technology available, including new diagnostic tests, and some novel vaccine platforms. What we lack at this point is the funding to stock a vaccine supply for the protection of our livestock industry. This is one of the discussions that is ongoing with the current farm bill—how to fund an FMD vaccine bank adequately so we can get a true vaccine stockpile and not just an antigen bank,” Oedekoven said.
RISKS FOR AN OUTBREAK
The risks are not decreasing.
“People, animals, and animal products travel fast in our global economy, increasing the risk of potential introduction of foreign animal disease such as FMD. The movement of people traveling from FMD affected countries is astounding and this is one of the most likely ways it could come into the U.S.” he says.
There also are a number of animals and related products that come from other countries.
“We import feed components for our livestock that could potentially be contaminated at a number of different points along the way. There are many potential concerns,” Oedekoven said.
A global economy has some drawbacks. People who come from other countries may inadvertently bring the virus with them on their clothing, baggage, etc.
“Our border inspection processes are a challenge,” he said. “Inspectors generally do a good job, but the amount of work they are tasked with completing is mind-boggling. There is not enough staff nor time to do the kind of thorough inspection we’d all prefer. That’s the reality of global economy and travel.”
When considering foreign animal diseases, FMD is often the example we discuss because it is so contagious, affects multiple species, and would have a crippling impact.
“There are some things that people need to understand, however. First, FMD virus does not affect humans; it is not a human health issue. It does affect livestock production but most livestock affected with the virus survive. It affects health and production (rate of gain) because the mouth is sore and the animals can’t eat well, or they are lame. For dairy animals it can be devastating; they get lesions on their teats and quit milking,” Oedekoven said.
“When talking about a vaccine bank, and diagnostic tests, we need to keep in mind that if we were to get an outbreak, we’d need to maintain consumer confidence in our products. Sometimes we talk about FMD in such a way that we scare our consumers into thinking it’s something that would cause milk or meat to be unsafe and would be a human health issue. We need to start turning the discussion of FMD away from fear and make it more of an education. It’s something we don’t want in our herd. We spend a great deal of time on training and preparing for this disease. Its primary impact would be the economic loss of our exports, as well as on an individual production basis in affected herds,” he said.
“What we’ve seen in other countries that have experienced outbreaks is that the majority of the farms are not affected by the virus, but they may be significantly impacted by the control measures,” Oedekoven said.
Control measures may affect how producers market their livestock, when and where they move livestock for production purposes, as well as recreational activities such as livestock shows and rodeos.
“One tool being developed is the secure beef supply plan. This plan is patterned after other secure supply plans including the secure egg supply and secure pork supply plans. Animal health officials used parts of the secure turkey supply plan when we experienced an outbreak of Avian Influenza in South Dakota in 2015. If the secure beef supply plan were to be implemented in an outbreak, ranchers would adopt biosecurity practices and would be looking for clinical signs of the viral infection,” he said.
“Participants in the secure beef supply program would be observing their livestock closely for clinical signs associated with the disease. Testing by local veterinarian in cooperation with state and federal animal health officials is also part of the plan. The goal is continuity of business — allowing for unaffected herds of low risk to continue to market calves. The Dakotas export calves to other states to be fed. The cow-calf sector would be negatively affected if the states south of us are less willing to take our calves if FMD were to be identified here. If we had participants in a structure where there is ongoing observation and testing, this could potentially minimize the impact of those stop movement orders, allowing unaffected low-risk animals to move,” he said.
“These are some of the tools that are in the development phase at this point, to allow continuity of business in the event of a foreign animal disease. We have moved past the idea of drawing a circle around everything, killing the animals and putting them in a hole and burning them. That plan doesn’t keep our livestock industry viable. Like any disease (such as TB recently) our goal is to work through it to maintain the viability of our livestock industry as a whole, as well as individual farms and ranches, to the extent possible,” he said.
“These are some of the things we are working on now, and this goes right along with having good, rapid diagnostic tests, and effective vaccines that are safe to use, and safe to have on our mainland,” Oedekoven said. F
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