Because it’s a disease of unknown severity, and possibly highly contagious.
You need to start worrying about it when 3 people have caught it, because if you wait until a “significant “ number of people have caught it, it’s too late to stop another pandemic.
If COVID taught us anything (spoiler: it didn't) you need to start worrying about it even before people catch it. Have a pandemic playbook and follow it, for one.
It's like 2020 is on replay, with the exact same downplaying, nearly word for word.
You need to start worrying about it when 3 people have caught it, because if you wait until a “significant “ number of people have caught it, it’s too late to stop another pandemic.