Well, given that from what you've said most of the elderly care staff rotates between facilities, all you really need is a handful of the staff getting infected and then them being in the same room as other care staffers who have a different schedule and go to locations the already infected members of the staff don't. Works even better when there's the occasional group briefing or contact by staff members outside of work, both of which are likely, especially early during an epidemic when nobody knows there's an epidemic going on.
COVID's nastiest trick isn't how easily it kills or cripples. It's how sneaky it is.
COVID's nastiest trick isn't how easily it kills or cripples. It's how sneaky it is.