Coronavirus update 2 March 2020. COVID-19 exported from China to rest of world.
COVID-19 novel Coronavirus has been exported from China to the rest of the world.
1. Rest of World daily new cases in green overtook new Chinese cases in dotted purple a few days ago. New RoW cases peaked around 1300, new China cases bottomed around 200-400. Total global new daily cases have also turned up due to export of COVID-19 to the rest of the world. The epidemic is now driven by areas outside China:
Rest of World cases on an approximately exponential uptrend, doubled on average every 6 days: The exponent of the curve is around 0.12. A value of 0.7 would be a doubling in 1 day. 0.12 is about 1/6 of that so doubling time was 6 days on average. However, it has accelerated lately; doubling time more like 4 days in steeper portion:
Logarithmic chart of the above shows acceleration in daily % rate of increase as slope is increasing slightly in recent days:
Another view showing the last part of the above charts. Exponent is nearly 0.24 which indicates doubling of cases every 3 days approx:
South Korean cases explode to 3700+:
As things are: the rest of world cases are the broadening wedge at the top of the graph. The total world cases minus China cases gap is widening and accelerating away from decelerating the Chinese S-curve. This means causing a new acceleration in total world cases is caused by cases outside of China. It has worsened since I copied this chart from my Excel spreadsheet: WL is date of Wuhan lockdown; day 4, 24 January 2020. CQ is quarantine date for other citie, though travel restrictions from Wuhan/Hubei were in place probably just after the WL point. Note that cases still increased from around 1000 to 4000+ before any deceleration started. The jump was because of the one time addition of clinically diagnosed cases in Hubei province but the deceleration in China resumed and an S curve was forming. My forecasts predict when the top of the S curve occurs (87000 cases and 3500 deaths approx for China). See next post.
This has implications: The top right opening wedge representing rest of the world cases in late February looks like the bottom left initial take off of Chinese cases in late January. Note how long it was (2 weeks+) before the Wuhan lockdown became effective and started to control the situation.
The shape of things to come? China S-curve flattens out but new epidemics in other countries may give a chart like the one below:
Direct comparison of almost perfect exponential uptrend in late January caused mostly by Whuan outbreak with approximately exponential outbreak in rest of world cases later. The formula shows the exponent of the China outbreak was 0.4 (doubling in around 1.5-2 days) and the rest of the world exponent is 0.12-0.13, doubling around 6 days on average but accelerating:
The exponents of the curves are showing the doubling time averaged over these short periods of time:
China (Jan 2020) 0.394 = doubles every 1.75 days approx.
Rest of World (Feb 2020) 0.271 = doubles every 3 days approx.
South Korea (Feb 2020) 0.330 = doubles about every 2.5 days.
What happened in China is that the daily rate of change decelerated over time in February but was still very high, going from 30% to 20% to 10%, etc., taking total case numbers to 40,000-50,000 before a significant slowing in the increases occurred. Log charts of total case numbers show this is well as plots of daily % rates of change. This enabled my forecasts to be fairly accurate and consistent over the past few weeks, spoiled only by the spike in new cases around 12 February where around 16000 clinically diagnosed cases appeared over a couple of days. However, that was a one time event and the forecast model still worked.
Unfortunately the rest of world daily % case increases are not starting to slow yet meaning that they are in an explosive exponential phase.
In my view, the only thing that slowed down the China epidemic was the sealing off of Wuhan and strict quarantines in other Chinese cities and regions. Will other countries have the ability to do this. Perhaps not. Western countries are paralysed by politically correct BS and are hesitant even to take timely measures, let alone draconian ones. This will greatly compound the problem. Every day wasted means 20% more cases.
1. Rest of World daily new cases in green overtook new Chinese cases in dotted purple a few days ago. New RoW cases peaked around 1300, new China cases bottomed around 200-400. Total global new daily cases have also turned up due to export of COVID-19 to the rest of the world. The epidemic is now driven by areas outside China:
Rest of World cases on an approximately exponential uptrend, doubled on average every 6 days: The exponent of the curve is around 0.12. A value of 0.7 would be a doubling in 1 day. 0.12 is about 1/6 of that so doubling time was 6 days on average. However, it has accelerated lately; doubling time more like 4 days in steeper portion:
Logarithmic chart of the above shows acceleration in daily % rate of increase as slope is increasing slightly in recent days:
Another view showing the last part of the above charts. Exponent is nearly 0.24 which indicates doubling of cases every 3 days approx:
South Korean cases explode to 3700+:
As things are: the rest of world cases are the broadening wedge at the top of the graph. The total world cases minus China cases gap is widening and accelerating away from decelerating the Chinese S-curve. This means causing a new acceleration in total world cases is caused by cases outside of China. It has worsened since I copied this chart from my Excel spreadsheet: WL is date of Wuhan lockdown; day 4, 24 January 2020. CQ is quarantine date for other citie, though travel restrictions from Wuhan/Hubei were in place probably just after the WL point. Note that cases still increased from around 1000 to 4000+ before any deceleration started. The jump was because of the one time addition of clinically diagnosed cases in Hubei province but the deceleration in China resumed and an S curve was forming. My forecasts predict when the top of the S curve occurs (87000 cases and 3500 deaths approx for China). See next post.
This has implications: The top right opening wedge representing rest of the world cases in late February looks like the bottom left initial take off of Chinese cases in late January. Note how long it was (2 weeks+) before the Wuhan lockdown became effective and started to control the situation.
The shape of things to come? China S-curve flattens out but new epidemics in other countries may give a chart like the one below:
Direct comparison of almost perfect exponential uptrend in late January caused mostly by Whuan outbreak with approximately exponential outbreak in rest of world cases later. The formula shows the exponent of the China outbreak was 0.4 (doubling in around 1.5-2 days) and the rest of the world exponent is 0.12-0.13, doubling around 6 days on average but accelerating:
Superimposing the curves for China January and rest of world February and South Korea February, recent portions of curves. Potential for South Korea of Rest of World (one place or many) to be Wuhan 2.0, 3.0, etc.
China (Jan 2020) 0.394 = doubles every 1.75 days approx.
Rest of World (Feb 2020) 0.271 = doubles every 3 days approx.
South Korea (Feb 2020) 0.330 = doubles about every 2.5 days.
What happened in China is that the daily rate of change decelerated over time in February but was still very high, going from 30% to 20% to 10%, etc., taking total case numbers to 40,000-50,000 before a significant slowing in the increases occurred. Log charts of total case numbers show this is well as plots of daily % rates of change. This enabled my forecasts to be fairly accurate and consistent over the past few weeks, spoiled only by the spike in new cases around 12 February where around 16000 clinically diagnosed cases appeared over a couple of days. However, that was a one time event and the forecast model still worked.
Unfortunately the rest of world daily % case increases are not starting to slow yet meaning that they are in an explosive exponential phase.
In my view, the only thing that slowed down the China epidemic was the sealing off of Wuhan and strict quarantines in other Chinese cities and regions. Will other countries have the ability to do this. Perhaps not. Western countries are paralysed by politically correct BS and are hesitant even to take timely measures, let alone draconian ones. This will greatly compound the problem. Every day wasted means 20% more cases.
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