I believe they will be tracing indivuals who died of Influenza Pneumonia or other respiratory diseases who travelled to China or were exposed to travellers from China beginning with deaths from December 2019 as well they will test recovered patients which will net fastest results..
From this point we establish if we need to go further back and then of course month by month until we either define antibodies in the living and deceased persons systems or we don't.
There is a significant body of anecdotal reports from people around the world who have had especially hard to budge Influenza and other respiratory diseases in the Northern Hemisphere fall period as well as late spring early summer in the Southern Hemisphere.
Many illness have similar symptons to the ones reported for Covid 19 and as far as I read people have gotten illness which really had no likelihood of being contracted by them in the normal situations. Such as Whooping Cough in an over 50 male who had no exposure to Child or anyone with the illness. The doctors said whooping cough and told him to confine himself for a fortnight. At which time he was reassessed and told to wait another week. Once all clear given he returned to work.
Was this for example a common mis diagnosis because physicians did not know their was any new virus to be looking for let alone a testing method.
Personally through a few other pieces of information out of China last year I think it was well and truly a problem in certain regions by June or early July. Time will tell and people will want to know if only to request compensation from Chines Authorities.
