In Korea, when someone is confirmed to COVID-19, we call that person '확진자'. It pronounced [확찐자]. It is just as same as a phrase '(살이) 확 찐 자', which means 'a person who has gained lots of weight too fast'.
So if you meet a Korean who said, "아, 나 확찐자 됐어.", you don't need avoid or afraid of him. You just asking him for an exercise, or just say, ”아니야, 하나도 안 쪘어요(No, you're not).”, even though you’re lying. ;-)