Re: Decentralised
"The report on the Beeb web site says they've picked up 4,000 who then tested positive, about 25% of the known cases. But they sent out 79,000 alerts so that looks like 95% false positives. "
95% false positives is one person passing it onto 1 person in 20 they came in contact with - did you come in contact with someone that passed on the virus or did you just come in contact with some who was later found to have the virus but didn't pass it on. And just how many people do you come into contact with each day if things return to some semblance of normal? 10? 50? 100? 1000? More?
South Korea had success with contact tracing because they ignored privacy concerns, deployed it quickly to a small population that had a high proportion of smart phones and could be treated relatively easily/successfully (i.e. 20-40 year olds).
And then there is the question of what is the actual spread of the virus - very low (<1.2m cases in ~4 months based on ~225k cases in the UK to date - that assumes the detected cases fall into the 20% of cases serious enough to reach a hospital for testing and is meant as an upper limit for small scale infection with high death rate) in which case the number of cases is likely to be traceable or is it much higher but difficult to detect in most non-serious cases in which case the number of actual cases is much, much higher and contact tracing will likely find super spreaders too late.
That then morphs over time into the question of whether the Swedish approach (no lockdown, we're in this for the long haul) or the lockdown/test/trace contacts approach is the correct way to treat it over the longer term. Lockdown definitely capped patient numbers in the short term based on data from multiple cities/countries and testing is definitely needed to understand the virus better, but whether they alter the death toll and number of patients over a longer time frame is less certain if a silver bullet vaccine takes 1-2 years to appear.
That's not to say contact tracing, testing and masks don't serve to reduce distress in the general population. The value of placebo's should never be underestimated.
Biting the hand that feeds IT
