Employers still have obligations to manage both the privacy of its employees, as well as their health and safety.
In the first instance you should always seek your employees consent to disclose any personal details about them, including their health.
Scenario One – Let’s assume that the employee diagnosed with COVID-19 has been at work and some of your other employees may have been exposed – in this instance you have obligations to inform and ensure the employees that may have been exposed then follow the correct procedures. You should endeavour to let your employee know that you need to advise their colleagues of their health status.
Scenario Two – Let’s assume that the employee diagnosed with COVID-19 has not been at work and no one in the workplace has been exposed. In this instance you are unable to disclose their medical status without their prior approval.
I’m sure there are some nuances, so feel free to reach out for further clarity.