The new influenza strain that is spreading has been identified as a "swine flu" because of what it has in common with previous viruses, but so far it has not been found in swine, according to Dr. Jim McKean, Iowa State University swine veterinarian. However, pork producers are being advised to keep people with flu symptoms away from their hogs.
The possibility of a worldwide influenza pandemic may have implications for swine producers in Iowa, he says.
The new recombinant virus has genetic components previously seen in strains of human, avian and swine influenzas, McKean says, 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," he notes. He says it was identified as a swine flu because of its similarity to other swine flu strains identified previously.
So-called swine flu is not spread by pigs
"Hogs are not necessary for this influenza to spread," says McKean, 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 says 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 says 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 says.
The ISU diagnostic lab does a lot of analysis of virus strains, looking for ways to handle influenza strains that do show up in swine, he notes, 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.
Iowa Department of Ag is monitoring situation
Iowa Secretary of Agriculture Bill Northey and the State Veterinarian for Iowa Dr. David Schmitt on April 30 issued the following statements regarding the new H1N1 flu strain that has been referred to by many people as the "swine flu."
They reiterated that you cannot get the disease by eating pork and there is no evidence of this flu in the pig population of Iowa or any state.
The State Veterinarian's office is working with the Iowa Department of Public Health, Federal Veterinarians and those in private practice to have a system in place to monitor Iowa's pig population for significant disease, and those efforts continue around the current outbreak.
If you detect illness in pigs, call the vet
Research is underway by USDA to determine if the disease can be spread to swine, but meantime Northey and Schmitt are encouraging Iowa pork producers to exercise extra diligence in their long held bio-security practices to continue to protect the health of their animals. If producers do observe any respiratory illnesses in their pigs, it is important that they do contact a veterinarian.
Secretary Northey and Dr. Schmitt released this statement: "There is no evidence that this strain of flu can be spread to pigs, but it is a good reminder to pork producers to continue their efforts to protect the health of their animals. Limiting access to your buildings, keeping workers who are ill away from the animals, and contacting a vet if any of your pigs do show signs of sickness are all best practices. And they make even more sense in the current situation."
"I want to remind Iowans that pork is safe to eat and our swine population remains healthy," says Schmitt. "The Iowa Department of Agriculture has been communicating with Iowa veterinarians about the situation to help keep them informed and give them access to the most up-to-date information."