How long to self isolate with plural positives

[Enko]

I have googled to find this answer but I can't find anything that deals with it.

As I understand it if a household has 1 person with a positive test they all start to self-isolate from positive test for 10 full days

If another person tests positive in this period their 10 days restarts but it does not restart for others.

My dd (21) believes that it restarts for everyone.

We are not fully sure either of us has it right - this is for dd who is in this situation with her flatmates 1 positive 5 days ago and they have isolated since another got a positive lateral flow test today.

(PCR tests booked for both dd and her other flatmate with the positive lateral flow test for tomorrow)

Only restarts for the newly positive person. So ideal situation is to not get it, but if your going to catch it, the earlier the better!

I believe the 10 days restart for everyone apart from the first person to test positive because their 10 days of being infectious are surely up?

Otherwise you'd forever go in circles as tests will stay positive for a good while after having recovered.

Just my opinion though.

10 days only starts again for the newly positive person. I asked track and trace this myself as I would have thought everyone would start again too, but no, not the case

This graphis is from public health England.
The 10 days only restarts for the person who tests positive.

@HungryHippo11 thank you I had seen that graph before but I could NOT find it yesterday.