You would have to notify the hospital so they can give you a private room. Perhaps call the Dept of Health for their opinion on it, they could even notify the hospital for you. I'm not exactly sure how it works.

When I had DD2 a friend of my mum's came to visit with a shocking cough, turned out it was whooping cough. We had to notify the hospital and also get antibiotics for myself, the kids and the baby as she came into contact with all of us. Luckily though I had my own room so she didn't expose any other babies to it.