From reading the NPR link in your comment - the CDC did not respond initially because there was no story - hantavirus is well known in the SW US and is usually only news locally (or when the wife of a movie star dies from it). Once the media ginned it up as the next chicken-little ski-is-falling narrative they issued a response.
Yes, I know it’s been a problem in the SW. And, yet another reason you’ll never get me on a big cruise ship. Floating Petri Dish! *SHUDDER*