My nephew has Mercer....how long is it contagious?

My step-brother, his wife and their 14 month old little boy are coming to visit for Thanksgiving. They will get to our house on the 24th. My concern is that their little boy just got diagnosed with Mercer disease (a very serious and potentially life threatening Staph infection) today. I have a 16 month old little girl and I am not sure if it is still a good idea for them to come out and visit. I tried looking on-line for information about how long someone is contagious and could find nothing. I will be calling my daughter's pediatrician tomorrow about this but does anyone have experience with this disease? Will it be safe for their son to be around my daughter by the time they get here? If you have any information I would be glad to hear about it! Thank you!