Sorting Out Swine Flu Concerns

A University of Iowa study suggests people working directly with pigs have a greater chance of developing antibodies to influenza viruses found in pigs without developing illness.

The study follows media attention of human infections from avian influenza virus in Asia.

Paul Sundberg, DVM, vice president of science and technology at the National Pork Board, says pork producers and consumers need to know the facts about potential exposure that has sparked growing concerns.

“The investigators’ concern is that if the H5N1 avian flu virus circulating in Asia infects the U.S. swine population, people with occupational exposure to pigs would be at greater risk for transmitting the virus to their surrounding communities,” observes Sundberg. “There is similar concern that swine workers might introduce a flu virus to swine herds, causing outbreaks among swine.”

While those concerns may be theoretically valid, the actual risk now is very low. The H5N1 virus is different from swine flu viruses present in the United States. The H5N1 virus has not been detected in the United States. “There is no scientific evidence that the H5N1 (avian influenza) has been transmitted from pig-to-pig or from pig-to-human,” Sundberg notes.

Unlike other parts of the world, U.S. pork production is mostly confined, limiting contact with birds carrying the avian influenza virus. “It is possible for humans to transmit some influenza viruses to pigs, and it’s possible, though not common, for pigs to transmit some influenza viruses to humans,” says Sundberg.

“The University of Iowa study shows people have had contact with the typical influenza virus. However, the study contains no evidence that the workers or veterinarians developed clinical illness or transferred influenza viruses to other people,” he adds.