A new variant of the H5N1 bird flu — the same one that led to the death of a Louisiana man — has for first the first time been found in infected U.S. dairy cattle.

The new H5N1 version, known as D1.1, was found in dairy cattle in Nevada and is different than the B3.13 type that has spread to more than 950 herds in 16 states over the past year, starting in Texas. The D1.1 infection was discovered by testing raw milk under a USDA dairy surveillance project launched last year.

As bird flu continues to spread across the United States, questions have emerged about the risk of contracting the virus from milk and eggs. Additionally, hundreds of dairy cow herds have been affected,