A few weeks ago we brought you an episode about the outbreak of bird flu caused by the H5N1 virus.

As you probably know by now, it's been spreading in dairy cattle in some parts of the country.

I promised that I was going to monitor the situation

and talk to experts on the ground

about what the spread of the virus might mean

for animals and for humans.

And I wanted to be really honest with you about any updates.

So here's what we know.

It is still being transmitted primarily between wild birds, livestock, and other mammals,

including now foxes, raccoons, and mice.

But there have been some new developments.

For the first time, the CDC has confirmed that a person infected with bird flu in the United States is experiencing acute respiratory

symptoms.

This person represents the third human case, all of them farm workers, all of them tied to the dairy cattle outbreak.

The first two patients, as you may remember, only had mild symptoms related to the eyes.

First of all, I want to be clear. We are not ringing any alarm bells here, but we do want you to be aware of what is happening, to be informed, and to be prepared for what may come. So far, the bird flu does not appear to be transmitting from

human to humans in this outbreak, but at the same time it is evolving. That third farm worker

I just mentioned, the one who developed respiratory symptoms,

an unprecedented number of mammals now infected so far.

That kind of means this thing is changing.

It's on the move. And so of course, probably like you, I have questions.

If humans do get sick from this strain of bur flu, how bad could it get? How sick would they get? Do we have an effective treatment?

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