So 3 staff had gotten sick that flu season. Staff who work with infectious diseases and probably get every cough and cold checked out just in case. Seems pretty baseline average to me.
That would be unusual. Given the proximity to the covid19 outbreak, there's a high probability that's the first known cases of covid19 - if confirmed.
People in China routinely go to hospitals for colds. It's cheap, and it makes you feel better, so why not.
Its already incredibly common for average Chinese people to go to a hospital for a cold, and I'd expect someone working in a virology lab would be even more likely to do so.
Maybe you're right, let's see how it plays out.