In short ... I think we should assume that it doesn't happen - and "move forward" from there.
In the UK most of the "cleaning services" are carried out by contractors; and regardless of what the Contract may or may not say, I suspect that most "cleaning operatives" prefer to avoid touching (anything they regard as) medical* equipment. In fact, I also suspect that medical staff advise them not to "touch anything", either.
Meanwhile, the nursing staff will always be too busy ... (too much kit; too little time)
On the other hand, departments such as Operating Theatres often have regular "maintenance mornings" where they give their domain a good old digging out (that usually offers a "window of opportunity" for the biomeds to get in there, too) - and ICU's and similar occasionally get a Deep Clean if (and when) a particularly nasty bug has raised its ugly head.
I have sometimes thought that there could be niche
opportunity for contractors to offer "special cleaning services" for equipment of all types; although, as I say, myself I would prefer that it was simply done as a matter of course during PM - at least that way the BME Manager could rest assured that it actually gets
done (or at least that's what we hope).
No doubt there are various "policy documents" scattered around; but unless policies are enforced then they are simply exercises in Wishful Thinking. The approach these days (in the UK at least) seems to be:- mustn't upset "the workers" (we have a "no blame culture", don't forget); and then when things turn out to be "less favourable than expected", we have another round of "lessons shall be learned", etc., etc.
(plus a few more policy documents, no doubt). Anything, that is, rather than having Managers grip the situation - and actually manage
(also known as being a Leader).
* Especially anything that may mean using a step-ladder (wall-mounted monitors, services pendants, etc.)