MIL is visiting two developing countries for several weeks. Do we need to wait before she visits with LO? Should I be concerned that she could be a carrier for diseases we aren't exposed to here? She goes to these countries every year or two so she may already have been exposed and won't show symptoms but could still transmit to others. Or am I just being overly cautious? We don't expect her to visit immediately after returning but we'd rather be safe than sorry. LO is 3 months old.