M.K.
Do you have any pets? Our dog and my father and brother passed strep around for almost a year before it was figured out that the dog was a carrier. MRSA is approprietly named because it is resistant to methacillin (I think I spelled that wrong). It could be that it got on his sheets, the carpets, the couch cushions, a high chair, door knobs, ANYTHING. A very good disinfecting would probably be a good idea. Also, although he finished his antibiotics, it might not have been completely out of his system, and when he stopped the antibiotics, it was able to flourish again. Do you go to any indoor kids playgrounds or such? Maybe he is picking it up there. I know that MRSA is a dangerous bug, and I hope Brett clears up and stays cleared up, for the family's sake.