AMES, Iowa -- The possibility of a worldwide influenza pandemic may have implications for swine producers in Iowa, according to Dr. Jim McKean, Iowa State University swine veterinarian.
The new recombinant virus has genetic components previously seen in strains of human, avian and swine influenzas, McKean said, but this specific H1N1 influenza virus strain has never been identified in swine. “Calling it ‘swine flu’ is a nomenclature issue, rather than an origin issue,” McKean said. He said it was identified as a swine flu because of its similarity to other swine flu strains identified previously.
“Hogs are not necessary for this influenza to spread,” McKean said, and all cases investigated so far “have had no swine contact whatsoever.” It transfers from human to human, and has nothing to do with pigs.
McKean said it is not known how the virus strain might affect swine, and because of that, hog producers should take precautions to keep it from getting into the swine population. “Pork producers should be minimizing the exposure of pigs to humans. . . . Keep people with symptoms out of hog houses until symptoms are gone.”
Another H1N1 influenza strain was identified in the 1918 flu epidemic. McKean said that flu strain, also identified as a swine flu, transferred from humans to pigs. If that happens with the current strain, it’s not known what the impact will be on the swine population. “Pigs are not likely to have a large amount of immunity, because it’s a unique strain,” he said.
The ISU diagnostic laboratory does a lot of analysis of virus strains, looking for ways to handle influenza strains that do show up in swine, McKean said, and this particular variation has never been identified in any of those studies. But the potential for the spread to swine provides an opportunity for pork producers to look at the biosecurity measures they have in place, and to increase them if necessary.
McKean was interviewed on the swine flu epidemic on Iowa Public Radio’s Talk@12 news hour on April 27. The interview is available online on the ISU Extension Market News Web site.