The disclosure that dairy herds in Nevada have been infected by a version of the H5N1 bird flu not previously seen in cows has put virologists and researchers on high alert. Among other things, the news from the Nevada Department of Agriculture suggests that driving the virus out of the U.

A dairy worker in Nevada has been confirmed to be infected by a new bird flu strain found to be spreading among cows in the state last week . That strain of the H5N1 bird flu virus, called D1.1 by scientists, is different from a previous variant called B3.13 which had infected at least 40 dairy workers in the U.S. to date.