More countries stand the chance of protecting, not destroying, livestock threatened by Foot and Mouth Disease (FMD), outbreaks of which cost European countries billions of dollars last year. New diagnostic tests developed through global research jointly sponsored by the IAEA and Food and Agriculture Organization (FAO) are enabling veterinarians to differentiate between vaccinated and infected livestock - a breakthrough that would allow FMD outbreaks to be controlled using vaccines with less reliance on mass slaughter.
It's a big step forward, says Bill Doughty of Commonwealth Scientific and Industrial Research Organization (CSIRO) Livestock Industries in Australia, which participated in the global research programme. He says that, right now, the use of vaccines to control an FMD outbreak seriously impedes a country's ability to trade livestock and livestock products. "The world organization for animal health - the Office International des Epizooties (OIE) - requires countries to show that they are free from diseases such as FMD in order to trade internationally," he explains. "Current tests cannot distinguish between animals which have been infected and those which have been vaccinated, so a country using vaccination as a control strategy will be prevented from trading livestock and livestock products."
FMD affects cows, sheep, goats, and pigs, and remains endemic in many developing countries, at a huge cost to agricultural economies Outbreaks of FMD in Europe in 2001 made headlines as one of the biggest agricultural disasters of the past decade. Estimated costs surpassed US $9 billion in the United Kingdom alone, where about four million livestock were slaughtered to prevent FMD from spreading. One reason why the animals were slaughtered was the inability to screen animals and separate vaccinated from infected ones.
"Research we've done changes the picture dramatically," says John Crowther, a scientist of the Joint FAO/IAEA Division's Animal Production and Health Section. "Tests were developed that can clearly single out vaccinated cattle, so that they can be identified as disease free, and protected from slaughter."
The global research programme was started in 1998 by the Joint Division of the FAO and IAEA in Vienna, Austria, with the aim of developing FMD diagnostic tests, based on applications of immunoassays developed through nuclear science. The work linked scientists from the world’s most advanced institutes with those in the developing countries and a number of commercial partners. Their collaborative efforts led to assays that could document the difference between vaccinated from infected animals. Three tests were developed and now are being proposed as candidates for commercial application.
At an international meeting in Australia in early March 2002, scientists from 15 countries in the research programme reviewed results. Meeting at the Australian Animal Health Laboratory, the most advanced laboratory in the world for animal pathogens, they agreed that each of the three assays works effectively. Still needed, they said, is full international validation of the tests, a process expected to be completed over the coming months within the framework of the programme.
Once validated, the tests can move into the marketplace. The next time FMD strikes, countries then can stand ready to control the disease and limit agricultural losses by protecting cattle, rather than resorting to mass slaughter.