My dad had an accident at work. Went to the hospital and tested positive for COVID upon admittance. Didnt really show symptoms. He stayed in the hospital for 3 weeks and did test negative after two weeks and several positives. He has been in a rehab facility since then, but had to have another surgery and when he got back to the hospital 7 weeks after first being admitted he tested positive again. No symptoms. Any clue as to what could be going on? He's in isolation again and his wife can't really see him.