Starting a new thread for data, analysis, research links & related discussion as the frequency of posts to the main COVID-19 thread makes it difficult to locate info that was posted even a day of two ago.
COVID-19 case growth trends plot updated to 28 March 2020.
Have split into separate plots to focus on specific issues.
First a few notes & qualifications.
- Day 0 in plot = the day when the number of cases was closest to 150. In the most cases the day 0 number of cases was within the range of 150±10, with the main outliers being the US (175), China (121), and South Korea (104)
- Data plotted are the absolute numbers of confirmed cases reported mainly by either Wikipedia or Worldometers.com
- The numbers of confirmed cases are subject to the extents and criteria of testing which vary between significantly jurisdictions and within jurisdictions, over time
- The numbers of confirmed cases will in most cases be less than the numbers of symptomatic infections due to both a lag between onset of symptoms and confirmation of infection and because restrictive criteria for testing mean many symptomatic people are not tested and hence not counted. In some jurisdictions though confirmed cases include people who were asymptomatic at time of testing.
- No adjustment has been made for differences in the populations of various countries.
- The initial rate of exponential growth in cases above ~150 is mainly a function of the nature of infection spread of the virus and various socio-economic and behavioural factors, and is largely independent of total population. Timing and extent of roll-off from exponential growth is dependent on containment measures and other restrictions implemented
Plot 1: East Asian vs Western countries
‘High Income’ jurisdictions only (per World Bank ranking + Taiwan)
Masks & other factors?
As per plot, the rates of growth in COVID-19 cases in Taiwan, Singapore, Hong Kong & Japan follow a very similar trend and are much lower than in the US and Europe. Twenty days after reaching 150 cases, Germany & Italy had 23 times as many cases as Singapore & Japan, and the US had about 80 times as many cases at the same stage. At least until two days after lockdown, NZ was clearly following the trend in US and Europe.
None of the four Asian countries have yet enforced mass business closures though in recent days restrictions do appear to be increasing. Tokyo subway trains & streets are still crowded, offices in the CBD still working.
In addition to rapidly implement widespread testing and stringent self isolation/quarantine requirements on infected individuals (possibly less so in Japan?), one notable difference is wearing of face masks in the East Asian countries.
One issue for these countries is that though at a lower rate, near exponential growth in cases is still continuing. Not sustainable in the longer term. Suggests that more aggressive measures are needed and in the last few days more stringent quarantine requirements on travellers have been implemented at least in some of the countries, along with requests for more social distancing and avoiding large gatherings. Will probably be 7 – 10 days before the effects of these measures are evident.
South Korea is different as they had an early large cluster of COVID-19 cases associated with a religious sect. But with most people wearing face masks, widespread testing, stringent self isolation/quarantine requirements, and school closures, they managed to bring a runaway growth in cases largely under control within about two weeks without mass business closures. The rate of increase in cases in South Korea is now lower than in Taiwan, Singapore, Hong Kong or Japan.