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.
There's no discussion of how many people work at the lab, how many staff visited hospital the year before that, whether it is in fact common for those staff to visit hospital when they have seasonal flu, or any other factors that would put this in any sort of context at all.
...but even still, 3 admitted to hospital for flu symptoms in that demographic is very high, statistically - even if literally ALL employees caught the seasonal flu at the same time.
And no its not a couple hundred. 600 people work at that lab. So 3 people with seasonal illness out of 600 at one time is incredibly unremarkable.
Yes, but these were three staff who work with infectious diseases and so would not be expected to use hospital resources frivolously. In fact, they would be considered shirkers to do so for a cold. If a doctor at a hospital needs an aspirin he merely takes it - he doesn't check into the hospital, take a bed, etc.