Canada is still wary of allowing shipments of British meat into the country following an outbreak of foot-and-mouth disease in the United Kingdom that was first reported in early August.
Although the European Union agreed last week to let all of Britain, except part of the County of Surrey, resume exports of live animals, meat and dairy products to other EU countries, Canada’s animal health watchdog is still monitoring the situation.
“We’re basically evaluating the information that the EU has provided, but as of this moment, imports from Great Britain are still restricted,” said Debbie Barr, the Canadian Food Inspection Agency’s national manager for imports and exports.
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“They’ve resumed exports to other EU member states, but not quite in a normal fashion. They still have additional conditions and restrictions in place that they wouldn’t have.”
Concerns about imported meat products are not without justification, she said.
The last major outbreak in the U.K. in 2001, which resulted in up to seven million animals being slaughtered, was traced back to meat products in untreated restaurant waste that was fed to livestock.
Canada has been free of the disease since 1952.
EU veterinarians, representing the bloc’s 27 member countries, backed a European Commission proposal to limit export restrictions to a surveillance zone in Surrey, 10 kilometres around the area where two outbreaks of foot-and-mouth disease were confirmed last month, according to Reuters.
“This means that exports of live animals, meat and dairy products will be able to resume from the territory of Great Britain, apart from the 10 km zone,” the European Commission said.
“This reduction in the control measures at this stage has been possible because of the favourable evolution in the disease situation and the strict and immediate movement ban implemented in the whole of Great Britain,” it said in a statement.
Britain’s farming minister Hilary Benn said, “this is a clear demonstration of the confidence which our European colleagues have in the disease control measures that we have taken in this outbreak.”
Britain’s deputy chief veterinary officer Fred Landeg expected exports to resume soon.
The surveillance zone in Surrey, where the highly infectious virus was found on two farms in early August, was expected to be lifted Aug. 30. The EU vets are expected to clear all British exports by Sept. 12, he added.
“The chances of finding another case of foot-and-mouth in the U.K. are very slim. But of course we still want people, in particular farmers, to remain vigilant,” Landeg said.
Canada is still wary of allowing shipments of British meat into the country following an outbreak of foot-and-mouth disease in the United Kingdom that was first reported in early August.
Although the European Union agreed last week to let all of Britain, except part of the County of Surrey, resume exports of live animals, meat and dairy products to other EU countries, Canada’s animal health watchdog is still monitoring the situation.
“We’re basically evaluating the information that the EU has provided, but as of this moment, imports from Great Britain are still restricted,” said Debbie Barr, the Canadian Food Inspection Agency’s national manager for imports and exports.
“They’ve resumed exports to other EU member states, but not quite in a normal fashion. They still have additional conditions and restrictions in place that they wouldn’t have.”
Concerns about imported meat products are not without justification, she said.
The last major outbreak in the U.K. in 2001, which resulted in up to seven million animals being slaughtered, was traced back to meat products in untreated restaurant waste that was fed to livestock.
Canada has been free of the disease since 1952.
Foot-and-mouth disease – the recent case
In August 2007, FMD was found at two farms in Surrey, England. All livestock were culled and a quarantine erected over the area.
The strain of the Surrey virus was identified as one linked to vaccines and not normally found in animals. A government interim report on the outbreak found a “strong probability” that the source of the infection was the Pirbright laboratory, operated by the U.K.’s Institute for Animal Health and Merial Animal Health.
What is FMD?
Foot-and-mouth disease (Aphtae epizooticae), sometimes called hoof-and-mouth disease, is a highly contagious viral infection belonging to the Picornaviridae family of RNA viruses. There are seven strains, called serotypes,of FMD.
What are the symptoms?
The average incubation period of FMD virus varies but is generally around three to eight days.
Clinical signs in cattle:
* High fever that declines rapidly after 2-3 days.
* Blisters inside the mouth that lead to stringy or foamy saliva and drooling.
* Blisters on teats and nostrils.
* Depression.
* Weight loss.
* Decreased milk production in cows.
* Testicular swelling in mature males.
* Lameness caused by the presence of painful blisters on the coronary bands, and space between the hoof claws.
* Large, bald areas left by ruptured blisters, may become infected.
Other animals:
* Clinical signs and lesions in pigs, sheep, and goats are similar to those in cattle, but milder, especially in sheep and goats. Lameness is the predominant sign in these species.
* The morbidity rate (the rate at which a disease spreads among a population) of FMD can be 100 percent. The mortality rate (the death rate in a diseased group) in adult animals is low (5 percent); but in suckling pigs and lambs, it may approach 75 percent.
* Though most animals eventually recover from FMD, the disease can lead to inflammation of the heart muscle and death, especially in newborn animals. Some infected animals do not suffer from or otherwise show signs of the disease, but carry FMD and can transmit it to others.
Where does FMD occur?
In North America, FMD was last reported in 1929 (USA), 1952 (Canada) and 1954 (Mexico). The EU adopted a non-vaccination policy in 1991. Recent, acute outbreaks in Taiwan, Japan, Korea, South Africa, Argentina and Europe have alerted FMD-free countries of the need for permanent FMD awareness. This is due to the continuing threat through illegal imports and global movement.
The outbreak of FMD in the United Kingdom in the spring and summer of 2001 was caused by the “Type O pan Asia” strain of the disease. This episode saw more than 2,000 cases of the disease in farms throughout the British countryside. About seven million sheep and cattle were killed in an eventually successful attempt to halt the disease. The county of Cumbria was the worst affected, with 843 cases. By the time the disease was halted in October 2001, the crisis was estimated to have cost Britain more than $16 billion in damages to the agricultural and related industries.
In Ireland the same year, a potentially disastrous epidemic was avoided by strict government policies on sale of livestock, disinfection procedures and the cancellation of large events likely to be attended by farmers. One case was recorded in the county of Louth.
The recent case
In August 2007, FMD was found at two farms in Surrey, England. All livestock were culled and a quarantine erected over the area.
The strain of the Surrey virus was identified as one linked to vaccines and not normally found in animals. A government interim report on the outbreak found a “strong probability” that the source of the infection was the Pirbright laboratory, operated by the U.K.’s Institute for Animal Health and Merial Animal Health.
Viral lifespan
The FMD virus can survive for long periods of time, depending on climate:
-
soil, sacking or straw 26 – 200 days
-
cardboard, wood or metal contaminated with blood 35 days
-
fat-contaminated wood 398 days
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experimental animal confinement rooms 2 days
-
wool 14 days
-
cow hair 28 days
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dry manure 14 days
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moist manure 8 days
-
liquid manure (12C to 22C) 34 – 42 days
-
wash water from pens 21 days
FMD virus survives almost indefinitely at freezing temperatures. Semen and embryos (unless treated according to protocol) can retain the FMD virus. Destruction of most strains occurs with heating to 56C for 30 minutes.
How does it spread?
FMD can spread over great distances through direct contact between infected and susceptible animals, and through indirect contact with contaminated animal products (meat, raw milk, hides), feed, bedding and inanimate objects.
Large amounts of virus will be present in tissues, milk, blood, semen, urine and feces shortly before the onset of clinical signs in cattle and pigs, and one or two days before the appearance of clinical signs in sheep.
Humans can carry the virus on hands, under fingernails, on clothes, on footwear, and on agricultural equipment and machinery.
Pigs amplify the virus — on average, one pig may excrete as much virus as 1,000 to 3,000 cattle, depending on the virus strain.
Concentrations of pigs can generate virus plumes that spread over considerable distances, if environmental conditions are suitable. In 1981, a case of FMD on the Isle of Wight was attributed to airborne virus that spread over the English Channel some 250 kilometres in distance. Canada does not have the environmental conditions to promote aerosol spread in large areas of the West.
Pigs are primarily infected by eating infected feed. Cattle are largely infected by inhaling infected aerosols; this is due to their much larger respiratory volume. Sheep are considered a maintenance host, exhibiting few clinical signs in spite of being infected and shedding virus.
Animals may also contract FMD via contaminated pens or vehicles used to transport livestock. The clothes and skin of animal handlers such as farmers, standing water, and uncooked food scraps and feed supplements containing infected animal products can harbor the virus as well. Cows can also catch FMD from the semen of infected bulls.
Can humans contract FMD?
Humans are rarely affected. Because the virus that causes FMD is sensitive to stomach acid, it cannot spread to humans via consumption of infected meat. In the UK, the last confirmed human case occurred in 1967, and only a few other cases have been recorded in countries of continental Europe, Africa, and South America. Symptoms of FMD in humans include malaise, fever, vomiting, red ulcerative lesions in the mouth and sometimes small blisters on the skin.
There is another viral disease with similar symptoms, commonly referred to as “hand, foot and mouth disease”, that occurs more frequently in humans, especially in young children. This disease is unrelated to FMD and is caused by a different virus.
Vaccination programs
Vaccinating for FDM is difficult. The seven strains (serotypes) of FMD virus continually evolve and mutate, creating a variation between and even within serotypes. There is no cross-protection between serotypes — a vaccine for one serotype won’t protect against others. This means FMD vaccines must be highly-specific to the strain involved. Vaccination provides only temporary immunity that lasts from months to years.
Health status
The World Organization for Animal Health recognizes countries to be in one of three disease states of FMD:
* FMD present with/without vaccination
* FMD-free with vaccination
* FMD-free without vaccination
Countries that are designated FMD-free without vaccination have the greatest access to export markets, and countries such as Canada, the U.S. and the UK maintain their current FMD-free without vaccination status.
On June 18, 1981, the U.S. government announced the creation of a vaccine targeted against FMD. This was the world’s first genetically engineered vaccine. The North American FMD Vaccine Bank is housed at a USDA laboratory off the coast of Long Island, New York.
FMD carriers
A carrier is an animal from which the virus can be isolated more than 28 days after infection. Ruminants may become carriers, with the virus persisting in the throat and mouth for up to three years in cattle, nine months in sheep and four months in goats. This carrier state exists in spite of natural antibodies or vaccines. It is estimated that 50 to 80 percent of cattle will become carriers, regardless of their vaccination status. Pigs do not become carriers.
FMD can spread directly through the movement of infected animals, indirectly by contaminated animal products or objects, and by air. A study of 880 primary outbreaks reported around the world between 1870 and 1993 reveals these causes of FMD outbreaks:
Cause of outbreak
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meat products 66 per cent
-
airborne sources 22 per cent
-
livestock importations 6 per cent
-
fomites (objects capable of transmitting infectious agents) 4 per cent
-
contaminated vaccines 3
Despite the various means of potential transmission, once FMD is introduced into a country, the primary means of spread is directly by contact with infected animals prior to recognition of the disease and by contaminated fomites.
Species at risk
FMD has a wide host range in wild and domestic animals, especially cattle and pigs. It can also infect deer, goats, sheep and other cloven hoofed animals such as elk, antelope, bison, and water buffalo, as well as elephants and hedgehogs.
Llamas and alpacas have a high natural resistance to infection. Some will develop mild clinical signs following direct contact with infected cattle, but will not transmit FMD to other camelids under field conditions. Horses are also resistant.
Web resources
www.inspection.gc.ca/english/anima/heasan/disemala/fmdfie/plan/plan-indexe.shtml
www.oie.int/wahid-prod/public.php?page=weekly_report_index&admin=0t
en.wikipedia.org/wiki/Foot-and-mouth_disease
– Sources: CFIA, World Organization for Animal Health, staff research
