The strain was detected through the agency's national milk testing efforts, which began in December.

Summary

The USDA has identified a second strain of bird flu in U.S. dairy cows, marking the first time a new variant has been detected in cattle.

Previously, all 957 reported infections came from a single strain.

The newly detected strain was prevalent among wild birds last fall and was found through the USDA’s National Milk Testing Strategy.

Bird flu has already caused significant losses in poultry, driven up egg prices, and infected nearly 70 people, mostly farm workers.