Health officials in the most populous state in the country have seen where the bird flu story appears to be heading, and they’re determined to stay ahead of it. Whether the rest of the nation is willing to follow suit remains to be seen.

Bird flu virus has swept through farms across the nation’s largest dairy producing state. All human cases had been mild - until now.

In a stark acknowledgment of the increasing seriousness of bird flu’s spread, Gov. Gavin Newsom of California declared on Wednesday that the outbreak of infections among the state’s diary cattle constituted an emergency.