I would imagine there's all sorts of employee relations issues if an employer were to disclose health information without the consent of the employee. I know my workplace never disclosed actual individual names when there were positives and restrictions on building entry. It got really odd early on when we were told there was a potential positive impacting the folks in my row of offices leading to a suggestion to quarantine. we never knew who it was so we really did not know if we had been near that person.