Yes I see - how would that work in the U.K. specifically? To identify all the cases? Has Matt Hancock said anything about having set up / setting up such a surveillance programme to find cases? I don’t remember him saying anything about it.
Case identification should work the way it normally does using public health personnel- the way it worked in Brighton originally for Covid19 and the way it worked Korea. Hancock's planner case identifications the app that never got going. The first stage of operation was people volunteering that they felt unwell. That seems very unlikely to be reliable. The second stage- capturing contacts by Bluetooth, was clever but also full of flaws.
The basic method starts with identifying a population at risk. For TB in Barnet that is a school. The whole school, teachers and pupils, are personally screened. For the initial outbreak in Brtighton all likely routes were screened and all contacts were identified and the spread was halted. The system is known and it is there. The only problem is that now the population at risk is 60 million UK residents. But all you need to do is recruit about 50,000 intelligent people with a biology background to follow procedures. Senior medical students might be a good group to use because their studies have been interrupted anyway. That would probably provide several thousand for starters.
There is much too much emphasis and reliance tests. We do not really need tests. I suspect that there are rather few people feeling feverish at present who not have Covid19. Normally one knows if there is 'a bug around' any virus that causes enough trouble to put people off work becomes part of daily conversation. With my daughter as a teacher we had strings of infections in the house but only about every two months and I suspect there are few if any going around now with lockdown.
So it is simple - assume that anyone feverish has Covid19. If there are pressing reasons to be able to exclude Covid19 so that someone can get back to work then test. But trying to pick up cases by testing is a complete waste of time. It will only pick up those in a short presymptomatic window and a negative test today does not mean you do not need one tomorrow. People would have to be tested daily.
Yes you will miss some asymptomatic cases but I suspect these are no more than quarter at most. The discrepancy between 1500 and 8000 is not asymptomatic cases. Its is that people have not been told to get tested if they feel ill - just isolate, which would be reasonable advice if everything else was in place.
Missing some cases does not matter because you can pick up the trail again next time theirs is passed on. Once you get to grips with trails you can work out how they extend both back and forward. Experience with tracing when it was up and running indicated that it worked - trails were terminated.
What needs to happen is for there to bean intelligent biologically trained person allocated to each cohort of 500-1000 people in the country. They need to be given the resources to keep that cohort free of virus by case identification, contact tracing and policing of quarantine however seems fit for the circumstances. For rural populations it is likely to be very different from metropolitan ones.
I have recently been in the middle of a TB tracing exercise. It took too long because of inadequate resources but it got sorted. An obvious feature of practice is that those involved do anything they think might improve their information base. There are rules for the basic plan of action but on top of that all sorts of double checks and sideways investigations are set up on the basis that they might clarify. An outsourced commercial service will not do that.
My prediction remains that infection rates will climb in June and that by July it will finally be accepted that things have to be done properly. I am beginning to think it may be nearer August.