Are you talking about 'isolating' or 'in isolation'?
Pretty much every case has been within those identified contacts who have been contacted and are self-isolating.
A) Oops I have had involvement maybe with that cluster Ill self isolate now. Gets tested soemtime, gets a positve, but has been largely out of circulation and has played the game of not spreaidng it
B) Oops I have had involvement maybe with that cluster (or didnt realise) but she'll be right, Ill go shopping and the beach, then gets tested positive