More details on how the patient contaminates their room even with the mask about halfway through the first video on the left:
https://www.youtube.com/channel/UCD2-QVBQi48RRQTD4Jhxu8w
(hint: think bathroom...)
Just to “close the loop” here:
There is a 15% to 20% hospitalization rate is a healthcare worker gets the disease. That is bad for them, but tolerable for the system.
However, if/when they test positive for the disease they need to be quarantined, and that puts them “out of action” for the period of the quarantine, exactly when they are most needed on site.