My 20 Year Old Grandson Has Returned A Few Weeks

My 20 year old grandson has returned a few weeks ago from South American 3 month trip. He is a healthy non smoker young man. For the last 3 or 4 days he tells me he is coughing blood. He has no cold or fever or pain, SOB. The Dr. is seeing him Mon for XRAY and Blood work. He is wondering if he needs to stay away from his cousins who are coming for a family birthday gathering here. Is it possible that he has something contagious? One of his cousins has a young family and is herself 6 months pregnant. Please give us advice.