USDA plans for discovery of new flu strain in swine, pushes prevention


Capital Press

Kimberly, Idaho, pork producer Dave Roper said the outbreak of the H1N1 influenza virus hasn't changed the already-strict practices on his farm.

Biosecurity measures have been in place for years, both for his own economics and for pig health.

His is a closed herd: Pigs that leave the farm are not allowed back for any reason. And he practices an all-in, all-out regime, where pigs stay in a group and move together through the various barns. Visitors to the operation are rare.

Practicing recommended biosecurity rules, including keeping anyone off the farm who has no reason to be there, can prevent swine herds from contracting the H1N1 influenza virus, said John Clifford, USDA's chief veterinary officer.

But while there are no known cases of H1N1 influenza in U.S. swine, USDA expects it will be found.

"We expect that influenza H1N1 will hit our swine herd, and that's why we're making the preparations we're making," said USDA Deputy Secretary Kathleen Merrigan.

USDA has implemented a swine influenza surveillance program to monitor and study the virus and is asking producers and veterinarians to report any cases in swine they find.

Swine flu is endemic in the United States, but there would be no confusion in determining which flu swine have, said Steven Kappes, USDA Agricultural Research Service deputy administrator for Animal Production and Protection. Diagnostic tests differentiate between the strains.

"ARS, very quickly after we got the genetic sequence of the isolate from Mexico, developed diagnostic tests within a week," Kappes said.

The H1N1 virus has been detected in swine in Canada, Australia and Argentina, Clifford said. Canada already has a number of cases in swine.

"With the exception of the very first case they found, in those other herds where they have found this novel H1N1, those animals have been successfully marketed with no issues," Clifford said.

Clifford said there is consensus among USDA, the Centers for Disease Control and Prevention and public health agencies that pigs that are sick with H1N1 influenza should fully recover before being moved to another facility or slaughter.

"Pigs recover from influenza and have very low mortality in that," he said. "So our message to retailers and consumers is pork is safe, and they should not have any concerns relative to this influenza virus or other swine influenza viruses that may be circulating out there today."

ARS is evaluating current swine influenza vaccines to determine if they are effective against H1N1, and has provided master seed viruses to five animal pharmaceutical companies to develop vaccines.

Clifford expects a vaccine for H1N1 to be available this calendar year.

"Whether they (producers) would need to vaccinate for this novel H1N1 will be directly dependent on the severity of infection we see in the human population and whether we start seeing cases in the swine population," he said.

In Idaho, Roper said his approach keeps his herd healthy, and he doesn't vaccinate.

"I don't think you should medicate an animal if it's not needed," he said. "But I do think it should be available."

Staff writer Carol Ryan Dumas is based in Twin Falls. E-mail:


USDA Animal and Plant Health Inspection Service:

USDA Agricultural Research Service: w

Centers for Disease Control and Prevention:

U.S. Department of Agriculture:

National Pork Producers Council:


Recommended for you