@Ruth54 As this person travels to your place during a pandemic, they are at risk of contracting Covid. Not sure why they would be concerned to that degree about the space they will arrive to. They should just stay home. Regardless, you have agreed to the Covid EC protocol, which presumably you are following, so you can outline for this person what your cleaning routine is. Of course, airing the space is one of the steps.
I would never ask previous guests about the state of their health, nor for their personal medical status, to share with a perfect stranger, no less. Good grief.
Personally, if this was my soon to be guest, I would be finding a way to cancel the stay. Too much possibility for things to go sideways.