By Jamie Martin
A large-scale study from the University of Missouri has revealed that a significant number of cattle across the United States carry antibodies for influenza A viruses. The study was aimed at understanding the history of flu exposure in cattle following the 2024 H5N1 outbreak in dairy herds.
Researchers tested 1,724 blood samples from cattle in 15 states, mostly from Missouri, using ELISA technology. The results showed nearly 34% of cattle had been exposed to influenza A viruses. While the samples included a wide range of cattle breeds, no signs of H5N1 were found.
Instead, the cattle showed past exposure to human seasonal flu strains like 2009 H1N1 and H3N2, as well as swine flu viruses including H3N2 and H1N2.
Some cattle tested positive for more than one flu type. The exposure was seen throughout the year, with more cases in colder seasons. Both male and female cattle were affected equally.
“You can have a string of generally very dry years or you could have a string of very wet years,” Kovacs pointed out. “How they respond depends upon what their preference is for taking risks in their farming business.”
The absence of H5N1 in this study contrasts with current USDA reports. The agency recently confirmed three new H5N1 outbreaks in Idaho dairy cattle, increasing the nationwide count to 993 cases across 17 states.
The virus also continues to spread among mammals. New cases include 11 domestic cats from six states, along with skunks, foxes, a house mouse, and even a bottlenose dolphin.
These findings emphasize the importance of keeping a close watch on cattle and other animals for influenza, as they can potentially contribute to the evolution of new viral threats.
Photo Credit: university-of-missouri
Categories: National