As agricultural authorities and epidemiologists try to get their arms around the scope of the latest confounding chapter in the decades-long story
On Wednesday, U.S. Department of Agriculture scientists released a preprint — a study that has not yet been peer-reviewed — describing for the first time what their investigations of 220 viral genomes from infected cows have so far turned up.
The study’s authors suggest that the spread in cattle started from a single spillover event from birds in the Texas panhandle that may have happened in early December.
“These data support a single introduction event from wild bird origin virus into cattle, likely followed by limited local circulation for approximately 4 months prior to confirmation by USDA,” the authors wrote.
The findings add more precision to what had previously been reported by academic scientists
The new analysis also offers a window into how the bird flu is changing as it spends time in the bodies of cattle.