Beyond HIPAA, aren't there confidentiality laws? Nurses who share this kind of information - wouldn't they be fired for that?
Do keep in mind that the person you reference who went into the hospital, the fact that they entered a care facility isn't exactly a secret (e. g. someone sees them walk in the door). It does not necessarily mean that anyone providing care said anything, as someone in the ER or walking down the street could have seen them enter the hospital.