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U.S. Department of Health and Human Services

Animal & Veterinary

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FDA Veterinarian Newsletter November/December 2001 Volume XVI, No VI

by Charles Eastin, D.V.M., Ph.D., M.P.H., M.B.A.

Foot and Mouth Disease (FMD) has ravaged the English countryside this year. Diseased animals have been found on approximately 2,030 farms, resulting in the killing of diseased and susceptible livestock on more than 9,500 farms. More than 600,000 cattle, 3 million sheep and 100,000 pigs have been killed as part of the effort to eradicate FMD in England. Many fields throughout the country that were once filled with livestock now stand empty.

All cloven-hooved animals are susceptible to FMD, which is caused by an enterovirus of the Picornoviridae family. England's current outbreak has been attributed to the highly virulent PanAsia O type virus. The disease does not readily infect humans. In the few documented human cases throughout history, symptoms were mild and followed by a complete recovery. While FMD is endemic in many countries of the world, most developed nations have eradicated the disease and ban the import of certain animal products to keep the disease out. In countries where the disease persists, economic losses are mainly due to decreased feed conversion and loss of export markets.

On February 20, 2001, FMD was confirmed in England. The disease was traced to a pig farm in Heddon-on-the-Wall, a suburb of Newcastle-Upon-Tyne in Northumberland. It is believed to have entered the country in meat that was illegally imported into England and served at a restaurant. Uncooked garbage from this restaurant was believed to have been fed to pigs that became infected with the FMD virus. Garbage can be fed legally to pigs in England provided that such feeding is accomplished under license and in accordance with applicable laws that specify the process by which garbage must be processed (i.e., it must be macerated and cooked). Because of extensive animal movement, the disease had spread throughout the country before authorities became aware of its presence. While farmers received full market value as compensation for every animal killed, this provided little solace for the loss of years, perhaps lifetimes, of effort put into the careful breeding of prime stock. In addition to the trauma and uncertainty for individual farmers, the activities that would normally help them to cope with loss were also disrupted. Biosecurity concerns resulted in the cancellation or closure of livestock markets, agricultural fairs and other activities that normally provide an opportunity for farmers to discuss and work through their problems. Even in these hard times, most farmers in the area felt a sense of duty to cooperate with authorities and willingly submitted to a cull of their livestock if the livestock became infected. Farmers know the tremendous impact FMD has on livestock production and markets.

The State Veterinary Service in England normally employs approximately 300 veterinarians. Due to the large number of FMD cases, the British government's  Department of Environment, Food, and Rural Affairs (DEFRA) invited the U.S. and many other countries throughout the world to assist them by sending veterinarians to work in England (generally for periods of 30 days). Veterinarians from all over the world responded to the call, and more than 1,000 Temporary Veterinary Inspectors (TVIs) were employed by DEFRA. The United States Department of Agriculture (USDA Animal and Plant Health Inspection Service, Veterinary Services, Emergency Programs) responded to the request and has sent hundreds of veterinarians to England to assist in the fight to eradicate FMD from the country. The USDA actively recruited U.S. veterinarians from many sources, including those employed by Federal, State and local governments, academic institutions, and clinical practices. In addition to providing needed assistance to England, the U.S. will greatly benefit by having a reservoir of veterinarians experienced in FMD identification, outbreak management, and multinational animal disease eradication efforts.

Teams of veterinarians from the U.S. arrived in London weekly. Upon arrival, veterinarians would proceed to DEFRA's main office on Page Street for orientation. The following day they would move to a regional office for additional training and possible assignment to a satellite office. TVIs were most commonly assigned to field positions, where they would be involved in:

  1. conducting surveillance of farms to detect FMD soon after infection
  2. culling of farms where disease had been detected
  3. investigating suspected cases reported by farmers
  4. providing second opinions for TVIs that were on farms where FMD was suspected
  5. conducting risk assessments for farmers that appealed the decision that their animals be culled
  6. oversight of biosecurity on farms

When FMD was detected on a farm, the farm was designated as an "infected premises" or IP. For 21 days from the time disease was diagnosed, disease surveillance visits were conducted on the surrounding area farms (those within 3 kilometers of the IP) every two days. On a surveillance visit, veterinarians examined animals to detect disease. All supplies used on farms were kept in the trunk (or "boot", as they say in England) of the vehicle instead of the back seat. Every effort was made to keep the interior portion of the vehicle clean and disease-free. Upon arrival at the farm, the veterinarian would park the vehicle outside of the farm gate on a public roadway with the trunk directed toward the farm entrance. To drive onto any farm (even one on which disease had not been diagnosed and was not suspected) would be considered a breach of biosecurity and may result in a vehicle unknowingly spreading disease. Biosecurity was particularly important considering that there were a limited number of veterinarians and many farms to be visited. If paperwork was required on the farm, it was placed in a plastic bag prior to the veterinarian getting out of the cab of the vehicle. This bag would also be disinfected before taking it onto the farm. The papers would be removed from the plastic bag to be completed while in the farmhouse and then returned to the plastic bag for transport back to the vehicle. A "disinfection line" consisting of a tub of disinfectant with a stiff-bristle brush and sponge was set up just outside of the trunk. Any equipment or supplies that the veterinarian needed to carry onto the farm were thoroughly disinfected and placed at the end of the disinfection line, perhaps in a bucket. The veterinarian would cover his or her clothing with disposable paper coveralls and a rubber suit. To prevent the spread of disease by footwear, boots (or "Wellingtons") were kept in the trunk of the vehicle and disinfected before proceeding onto each farm. Rapid reliable communication was essential should disease be detected on the farm during the surveillance visit. Cellular phones, particularly susceptible to moisture, were double bagged. To prevent the spread of disease, the phones remained in the plastic bags when they were used on the farms.

Generally, the farmer would meet the veterinarian and they would proceed to inspect and examine each susceptible animal on the farm. In addition to his or her role in disease detection, the veterinarian also provided advice on biosecurity measures taken by the farmer to keep disease off of the farm. Also, the social value to the farmer of interaction with the veterinarian was not insignificant as many of these areas were under stringent biosecurity restrictions that effectively prevented many of the social gatherings that are a hallmark of normal rural life.

If the veterinarian didn't find any infected animals, he or she would exit the farm. All equipment, including boots and the rubber suit was thoroughly cleaned and disinfected prior to being returned to the trunk of the vehicle. Paper suits and any other disposable supplies were placed in plastic biohazard bags, double bagged and returned to the main office for incineration.

However, if the veterinarian suspected disease in any of the animals, the entrance to the farm would be blocked immediately to minimize the chance of any further spread of the disease. After calling the office to report the disease, a more experienced veterinarian would arrive to provide a second opinion regarding the presence of disease. The main DEFRA office in London would then be called and the final diagnosis decision was made within hours of the veterinarian having arrived on the farm. Testing was considered a confirmation of the decision, but test results are not timely enough to be considered in the decision making process.

Handheld Global Positioning System (GPS) devices (part of the standard kit issued to veterinarians) were used to determine the exact location of the infected animal(s) on IPs. From this location, the three-kilometer surveillance zone was established. Within 24 hours of the time of FMD diagnosis, all susceptible animals on the IP were killed. In addition, within 48 hours, all susceptible animals on the farms adjacent to the IP were killed. The animals on adjacent farms were killed because there is an extremely high likelihood that they were already, or soon would be, infected.

Because of the ease with which FMD can be transmitted, extreme biosecurity measures were required on FMD positive farms, especially during the killing process. After confirming the diagnosis, the veterinarian would start the paperwork and prepare for a long afternoon (which frequently stretched late into the night). Office personnel arranged for required teams to converge on the IP within hours following diagnosis. Required teams included:

  1. case officers who acted as assistants to the veterinarian in charge
  2. an appraiser to value the animals for compensation purposes
  3. a slaughter team to kill the adult animals
  4. a headchute (or crush) with gates to ensure safe handling of livestock
  5. animal handlers
  6. a biosecurity team to ensure that all personnel and equipment entering and leaving the farm were properly disinfected, and for post-cull disinfection of the animal carcasses and area of the kill
  7. leak-proof truck(s) (or lorries) to haul the animals away from the farm for later incineration
  8. front-end loader(s) to load the animals into the trucks
  9. an escort to follow the truck(s) and ensure they did not leak

Perhaps one of the most important tasks of the veterinarian was to ensure that the killing of animals was performed in a proper and humane manner. Young animals were killed by injection of euthanasia solution by veterinarians, while older animals were stunned with a captive bolt by slaughter personnel and killed by inserting disposable pithing rods through the brain and into the spinal canal immediately following stunning. One reason for the use of disposable pithing rods was to eliminate the possibility (albeit remote) that workers would be exposed to the etiological agent that causes Bovine Spongiform Encephalopathy.

Occasionally, a farmer would appeal the culling decision because he or she didn't think that his or her live stock had been exposed to FMD. These appeals were frequently based on a belief that good biosecurity on the farm and/or distance from the IP resulted in a low risk that these animals were infected. In such situations, a veterinarian would conduct a thorough risk assessment to assess the likelihood that animals on the farm had been exposed to disease. This risk assessment was forwarded to epidemiology personnel for further consideration. This assessment included an interview of farm personnel, thorough inspection of facilities (including biosecurity measures taken by the farmer and personnel), measurement of the distances between the farm in question and the IP, and inspection of all susceptible livestock.

The total economic cost of the FMD outbreak in England has been estimated to be 2.4 to 4.1 billion British pounds (about 3.4 to 5.8 billion U.S. dollars). Nationally, twenty-five percent of English firms have been impacted. An FMD outbreak in the U.S., either deliberate or accidental, could easily cost many times this amount. This knowledge should help to reinvigorate every individual's vigilance to keep this and other exotic diseases from entering or re-entering the U.S. Undoubtedly, some diseases will gain entrance into the U.S. In these cases, early detection and eradication are essential to ensure the damage to the U.S. livestock industry is minimized. Travelers should be cognizant of the risks of bringing food and animal products into the U.S. from overseas (see websites listed below). Veterinarians should work to educate farmers about what symptoms are suggestive of exotic diseases. Farm workers should educate themselves about the usual symptoms of these diseases and keep them in mind when they inspect their livestock. Lastly, farmers should contact a government veterinarian immediately if the symptoms are suggestive of an exotic infectious disease. Our collective efforts will help to maintain the health of our livestock industries and keep our animals free of foreign animal diseases like FMD.

For additional information on FMD or England's FMD experience, visit one of the following websites:

Dr. Eastin is a Veterinary Medical Officer in CVM's Division of Epidemiology. He was a DEPRA Temporary Veterinary Inspector working on FMD during July and August 2001.