A variant of the H5N1 bird flu has now infected dairy cattle in Nevada, according to reports from the United States Department of Agriculture.

A second strain of bird flu has been detected in U.S. dairy cattle, marking the first confirmed infections of this particular virus in cows, the U.S. Department of Agriculture said.

U.S. dairy cattle tested positive for a strain of bird flu that previously had not been seen in cows, the U.S. Department of Agriculture said on Wednesday, ramping up concerns about the persistent spread of the virus.