Disease spreads fast Once discovered, officials must move quickly to contain highly contagious disease
LOUISVILLE, Ky. — A foot-and-mouth disease outbreak is not the end of the world, but it can ruin a rural community.
Lessons learned from other countries show that the disease is well on its way to infecting any animal with a cloven hoof once it is actually diagnosed. Countries dealing with it for the first time after a long hiatus need to be pragmatic about what needs to be done, said the head of program development for the Federal Emergency Management Agency in the United States.
“When we first identify the first case, from all the studies we have seen, it is actually not the first case. Time has passed, and that case can be somewhere else,” said Sebastian Heath at a foot-and-mouth forum at the National Institute for Animal Agriculture conference in Louisville April 15-18.
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The disease has been known since the 16th century but it was not until the early 1920s that scientists determined it was a virus, said Pam Hullinger of the University of California, Davis’s medicine and epidemiology department.
The U.S. has not had a case since 1929, while Canada’s last outbreak occurred in Canada in 1952.
The disease is highly contagious. A small amount can cause infection, but it is easily killed with vinegar or bleach. It does not usually kill animals, but it stops trade.
FMD is widespread and endemic in many countries. Many FMD strains of the virus often circulate in South America, Africa and parts of Asia.
The U.S. has had nine outbreaks, starting in 1870.
The worst happened in 1914 in Michigan and spread through a national dairy show and closed the Chicago Stockyards for seven months. About 3,500 herds were affected in 22 states and 172,720 animals were infected. The outbreak cost $4.5 million in 1914 dollars.
Another case occurred in California in 1924 and was thought to be introduced from a ship from Asia after its garbage was fed to pigs. Cattle, sheep and pigs were affected in the outbreak, which shut down Californian agriculture at a cost of $6 million.
Taiwan suffered extreme losses in 1997. A delayed diagnosis stalled the clean up. It affected only pigs, and four million animals on 6,147 farms were lost, which was 38 percent of Taiwan’s hogs. The outbreak cost more than $1.6 billion.
Vaccination was eventually used.
The country has had subsequent outbreaks and has been unable to achieve free without vaccination status from the World Organization for Animal Health. It has been unable to rebuild its swine industry or its ability to export.
It spread because officials did not shut down auctions immediately. Other problems included a vaccine shortage, improper disposal and a high density of farms in the infected area. Officials also struggled to disinfect vehicles because of cold weather.
Hullinger said the English outbreak in 2001 gave Canadian and American veterinarians a chance to see it first hand.
About 10,000 farms were depopulated, but only 2,000 were actually infected. This widespread culling may not have been the best strategy, but there were concerns about whether the public would accept vaccination.
The disease went undetected for three weeks on a hog farm and eventually infected sheep, where it spread through the auction system.
On the positive side, Hullinger said there was tremendous value in having animal and premises identification. The U.S. does not have this, he added, which will greatly hinder the country’s ability to respond and assess the full scope of an outbreak.
Human costs cannot be measured, and English farmers did not get good information on biosecurity or what was happening.
“It is really important that we understand there are significant impacts of these diseases, and these are things we can’t put numbers on,” she said.
At the same time, Uruguay battled its own outbreak with a different approach. The disease rapidly spread in a dairy region in the southwest, and 28 farms were infected within three days.
Three million cattle and eight million sheep were involved, and the livestock industry demanded vaccination. The country was the sixth largest beef exporter in the world at the time, and producers wanted to save their business.
Uruguay has been free of FMD without vaccination for 10 years.
Vaccinations are held in banks, and obtaining enough during an emergency is a challenge. The country started a vaccination program based partly on what was available from its own stores and other South American neighbours.
Two rounds of national vaccination took place in 30 days. Twelve million doses were used in each round of vaccination on 50,000 farms. About 2,000 farms had the infection, and only 7,000 animals were destroyed.
