I'd hoped we'd get a good Trace and Test system going before we let everyone loose but I think its now too late and we have to trust people to take responsibility for themselves.
I'ts a "world beating" system - Boris said so. And some other politician said the App (which was supposed once to be the key part of it) is no just the cherry (or maybe icing) on the top.
I have only seen figures so far for the 28 May - 3rd June (7 days).
The contract tracers had 8,000 who had tested positive in that period to track / trace.
Of those people, 5407 gave details of their close contacts, 2710 did not - either because they could not be contacted or they declined to give contact details. That's about one third of the initial set of people whose contacts may be unaware that they have been in contact with a positive case.
The remaining 5407 people (between them) provided a list of over 31,000 people. That's an average of 5.7 contacts per infected person. I did hear that the definition of close contact in this context was someone that they had been less than 2 metres from for 15 minutes or more. That should be only members of their households if they are following social distancing rules - so why so many contacts? If the 2,710 people who did not provide details of their contacts, had a similar number of contacts per head, that would generate about 15,500 more "close contacts"
Of those 31,000 plus "close contacts", 26,985 were contacted and asked to self isolate. So 4,000 plus people could not be contacted for some reason. Added to the 15,500 from above gives about 16,000 people who are unaware they have been in close contact with a positive case.
If the infected person knows the identity of their close contacts, surely they would tell them of the possibility of infection straight away, rather than just pass the information to the professional contact tracers and let them relay the message. And if they knew they had been in close contact with several people in a crowded train or tube for example but didn't know them from Adam or Eve, then there is nothing they or a contact tracer could do about it.