Friday, 24 July 2020

Hong Kong Covid: record cases in “Third wave”

From Worldometer 
They’re all calling this our “Third wave” with the “Second wave” being March, which I don’t get, because I can’t see a First wave in the chart above, and I don’t recall a First wave.
Whatever… we have a chart like no other, except Spain is having a bit of an uptick. Nothing to be proud of, especially since I’ve been banging on about how well Hong Kong has done…
Seems most of the new cases are from crews on ships and planes that were neither tested nor quarantined. Why not? I don’t know.
[Professor Gabriel] Leung said the “working hypothesis” or credible explanation was that the latest cases came from multiple imported infections in those previously exempted from quarantine and testing, such as sea and air crew members
Taxis and restaurants are also vectors.
That said, we still have very low cases and deaths per million, still amongst the lowest in the world.
Dean of the Medical School at HKU, professor Gabriel Leung says that the “R number” has dropped sharply from 3-4 a few weeks ago, to under 0.5 now, result of measures taken, that I call “soft lockdown”.
Leung warned on July 12 that the city’s Covid-19 reproductive number had shot up to between three and four people infected by a carrier, but he said on Thursday that the figure had plunged on the back of a raft of social-distancing measures, including school closures, two weeks ago.

The number fell to the current level of around 0.5 after more measures, including capping public gathering to groups of four, banning dine-in services at restaurants after 6pm and mandating mask-wearing on public transport, were put in place about a week ago.
It seems to me a pretty arbitrary set of measures that are assumed to be working.  Maybe they are. Maybe not. The measures used across the world are all over the shop and it’s going to take some pretty sophisticated analysis to work out precisely which ones have worked and which ones haven’t. School closures, for example: there is little to no evidence that school closures affect the spread of Covid one way or the other.