For the first time, testers have discovered a second bird flu variation in American dairy cows. The Department of Agriculture announced the new strain on Wednesday, Feb. 5.
Until recently, all dairy herd detections in the U.S. had been infected with a form of bird flu known as B3.13.
Researchers previously detected this new version, D1.1, only in wild birds and poultry, but has now spread to cows.
They were able to link this strain to a deadly human case in Louisiana last year. The victim contracted the virus after exposure to infected birds.
Humans infected with D1.1 have experienced more severe symptoms than those with the previous bird flu strain. However, the CDC said the risk to the general public remains low, and there is no evidence of the spread of D1.1 from human to human.
