What are my rights if a caregiver is diagnosed with a disease that could impact my mother's care?

Read the contract you signed first, but I think you'll well within your right to ask for another caregiver.

Could you be more specific though? Are you concerned that the disease is communicable, or that it will affect the caregiver's physical and/or emotional ability to provide care?

You might need to be cautious about a discrimination charge though, depending on what the disease is.

If this disease is something that can be passed from caregiver to patient, find another caregiver immediately. On the other hand, if it is something like arthritis that is not communicable, and you did not ask for an MD letter clearing them for work, you are stuck.

Just to clarify, is this caregiver someone you have hired from the outside? Or are you talking about your sister, for example?

How do you expect your mother's care might be impacted?