Los Angeles Times Federal officials have confirmed that three California dairy herds have suffered outbreaks of H5N1 bird flu, due most likely to the transportation of cattle and not exposure to diseased birds.
Health officials announced last week that they suspected cows at three Central Valley dairies had contracted the illness, and were awaiting testing for confirmation. On Tuesday, officials said those tests revealed that the strain of virus that infected California herds was nearly identical to that found in Colorado dairy herds — suggesting the infections were the result of interstate transfer of cattle.
The B3.13 genetic sequence found in the infected cows was clearly the result of “anthropogenic movement; essentially zero chance it was an independent spill from wild birds into these dairies,” said Bryan Richards, the Emerging Disease Coordinator at the U.S. Geological Survey’s National Wildlife Health Center. “So, if anyone is trying to blame wild birds: Nope!”