(Radio Iowa) – Iowa State University researchers say a sugar molecule they’ve found in the mammary glands of cattle is the so-called receptor that transmits highly pathogenic avian influenza. Professor Todd Bell, in I-S-U’s veterinary pathology lab, says their study could lead to measures that prevent the spread of bird flu, which has infected more than a dozen large herds of dairy cattle in northwest Iowa in recent weeks. “Our team across the street in the vet diagnostic lab kind of figured out the ‘what’ which is we have influenza in the mammary tissue of dairy cattle,” Bell says, “and now here in pathology, we’re trying to understand the ‘why’ and look at mammary tissue to understand why this virus is getting in.”

Researchers in Ames are working under the hypothesis that milking machines may be involved in spreading the virus from cow to cow.  “There’s multiple different routes that influenza can infect different species, but we want to look at that as a potential route,” Bell says. “What we’re trying to do is not only understand maybe how externally the virus is getting to the mammary gland, but more specifically, we’re trying to understand how and why this virus can infect mammary tissue, which prior to this, had been unreported in mammary glands of cattle.”

If they can track the transmission of the virus to milking machines, Bell notes one possible solution to stop the spread is quite elementary. “If a virus is present on milking machines and then is getting into mammary tissue as you attach those milking machines,” Bell says, “one way to potentially stop that would be to disinfect or clean those milking machines prior to milking.” Milk sold in grocery stores and by other retailers is pasteurized, and the F-D-A and dairy industry are stressing that there’s no threat to the milk supply because the pasteurization process neutralizes viruses. Bell agrees. “Everything that we’ve seen so far from a research perspective does say that,” Bell says, “that pasteurized milk is very safe, that heating to that extent renders the virus inactive.”

Bird flu isn’t usually deadly for cows, but it’s often fatal for birds. Since the start of the outbreak, the U-S-D-A says more than 97-million birds have been affected, while commercial poultry flocks where the virus is found are typically euthanized. The study was published in the July edition of Emerging Infectious Diseases, the Centers for Disease Control and Prevention’s peer-reviewed journal. Thirteen of its 14 co-authors are from I-S-U, including researchers and faculty from across the College of Veterinary Medicine.