Peking duck, salted duck eggs, duck soup: China is famous for its duck delicacies, and duck farms dot the country's agricultural belt. So last spring, when Chinese farmers noticed their prized birds were producing fewer eggs than usual, they began to worry. Egg production plummeted by as much as 90% in some flocks. Ducks were waddling about awkwardly, their coordination off kilter, and eating less than usual. Some died within days.
By the end of the year, an estimated 4.4 million ducks in Fujian, Shandong, and Zhejiang provinces, the swath of eastern China where duck farming is common, had caught the mysterious illness. And the outbreak reached at least six other provinces, along with rural areas outlying Beijing.
Enter microbiologist George Gao and colleagues at the Chinese Academy of Sciences in Beijing. By analyzing the affected animals, the scientists isolated an aggressive new flavivirus, a class of viruses that includes yellow and dengue fevers—the first flavivirus ever identified in ducks.
The discovery of what the scientists have dubbed the BYD virus raises some critical concerns. In addition to potentially devastating Chinese duck farming and the economy that depends on it, the flavivirus could put humans at risk. "Most flaviviruses are zoonotic," meaning they can be transmitted from animals to people, Gao says, "so infection of human beings cannot be ruled out."
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http://news.sciencemag.org/sciencenow/2011/03/chinese-ducks-felled-by-new-viru.html?ref=hp