The move comes after a week of falling pork prices and several of the United States' largest pork importers scaling back their purchases.
Chris Hurt, an agricultural economist from Purdue University says China, Russia and Ukraine already have refused to accept pork from the United States and other nations affected by the virus. China and Russia represented 27.4 percent of U.S. pork imports in 2008, he says. The 1.28 billion pounds bought by the two countries made up a large portion of the nation's 5 billion pounds of exported pork in 2008, making China and Russia the second and fourth largest international U.S. pork buyers. Altogether in 2008, Hurt says American hog farmers produced 23.3 billion pounds of pork in 2008.
"This could get much worse for the pork industry," Hurt says. "You've got other countries starting to follow the lead of Russia and China by limiting their import of our pork. Then there are the consumers worldwide who are linking the word "swine" to pork, even though this influenza strain did not come from swine." Lean hog futures for May dropped 8 percent from April 24 to April 29, Hurt says. The drop is especially dangerous for pork producers who already have faced a sharp rise in feed prices and the effects of the recession.
Meanwhile, Egypt ordered the slaughter of the nation's 300,000 swine in response to the spread of the virus, which has yet to cross Egypt's borders. The WHO criticized the move and stressed the safety of eating pork. The CDC also championed the safety of pork products.
While the cause and origin of the virus is not yet known, WHO and CDC say there have been no cases confirmed in swine. Agriculture experts are urging vigilance among producers to make sure the virus stays out of swine herds. In the meantime, WHO says it has scientists working on theories to track the origin of the disease.
Some theories include one by University of South Florida professor Mark Walters, DVM, who has done plague research and believes the virus could have originated in rural Mexico. His scenario lays out a pond infected with avian influenza from migratory birds. The virus is passed to birds in the vicinity of a local pig farm. Eventually, the virus jumps from the birds to the pigs, which are known to be "mixing vessels" for influenza. The multi-species strain of the virus could then be spread to the farmer, where it continues to mutate, leading to a pandemic.
Another theory, from Juergen A. Richt, a Regents distinguished professor of diagnostic medicine and pathobiology at Kansas State University's College of Veterinary Medicine, holds that the H1N1 virus and the 1918 Spanish flu virus are the same. For his study which will be published in the May 2009 Journal of Virology, Richt used a 1930 H1N1 virus sample. He says his studies show that the 1918 virus spread through the pig population, adapted to the swine and resulted in the current lineage of the H1N1 swine influenza viruses.
While there are many hypotheses, WHO Director-General Dr. Margaret Chan says pointing to cause and origin now would be premature. She says WHO doesn't yet have the answers but eventually will and then will make the information public.
In the meantime, the world is keeping watch on the virus' spread, with 365 cases being reported in 13 countries as of May 1. The U.S. has confirmed 141 cases with one death.
Check with dvm360.com for continuing coverage.