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<HTML>
<HEAD>
<link href='http://fonts.googleapis.com/css?family=Simonetta <view-source:http://fonts.googleapis.com/css?family=Simonetta>' rel='stylesheet' type='text/css'>
<style type="text/css" media="screen">
@import url( http://nrg.cs.ucl.ac.uk/mjh.css );
</style>
<TITLE>CoVID 19 Growth Rate</TITLE>
</HEAD>
<BODY bgcolor=white TEXT="#00000" LINK="#0000f0" VLINK="#8000a0">
<H1>CoVID 19 Worldwide Growth Rates</H1>
<P>
<font color="red">Updated: 30th March 2020, 03:33 UTC <B>All graphs have been updated, but very little of the commentary has been as my family insisted I did something other than graphs today. I have managed to add a new Central America graph covering Mexico, Panama and the Domincan Republic, and split South America into two graphs, as there appears to be two distinct clusters of behaviour. MJH</B></font>
<P>
This page presents historical SARS-CoV-2 coronavirus infection
information. I try to present it in a way that helps inform about how
the virus is progressing throughout the main outbreaks worldwide in a
way that allows countries to be compared and perhaps lessons learned.
The underlying infection and containment processes are complicated,
and conclusions you or I may draw from these graphs are not true
predictions. For that, you'd need much more data about what is being
done in each country, and about how the data is collected. Comments
are my interpretation only. Nevertheless, I hope you find it useful.
</P>
<P>
<a href="http://www.cs.ucl.ac.uk/staff/m.handley/">Mark Handley</a>, UCL.
</P>
<h2>Contents</h2><DL>
<DT><a href="#covid-eu">Graph 1:</a> <B>Cases</B>: Western Europe: Italy, Spain, France, Germany, Netherlands, UK</DT>
<DT><a href="#covid-eu-norm">Graph 2:</a> <B>Cases</B>: Western Europe: Italy, Switzerland, Spain, France, Germany, Netherlands, UK</DT>
<DT><a href="#rates">Graph 3:</a> <B>Increases</B>: Western Europe Daily Increases: Italy, Lombardy, France, USA, UK, Spain, Greece, Denmark</DT>
<DT><a href="#deaths-eu-norm">Graph 4:</a> <B>Deaths</B>: Deaths: Western Europe: Italy, Spain, France, Netherlands, Switzerland, UK, Germany</DT>
<DT><a href="#covid-eu-lom">Graph 5:</a> <B>Cases</B>: Italy, Lombardy, Switzerland, Austria</DT>
<DT><a href="#covid-eu-norm2">Graph 6:</a> <B>Cases</B>: Nordic Region: Italy, Iceland, Denmark, Norway, Sweden, Finland, South Korea</DT>
<DT><a href="#covid-eu-norm2b">Graph 7:</a> <B>Cases</B>: Nordic Region (offset curves): Denmark, Norway, Sweden, Finland</DT>
<DT><a href="#rates-nordic">Graph 8:</a> <B>Increases</B>: Nordic Region, Daily Increases: Italy, Denmark, Sweden, Norway, Finland, Iceland, Estonia</DT>
<DT><a href="#covid-eu-norm3">Graph 9:</a> <B>Cases</B>: Italy, Belgium, Ireland, Portugal, Luxembourg</DT>
<DT><a href="#deaths-eu-norm2">Graph 10:</a> <B>Cases</B>: Deaths: Italy, France, Germany, Luxembourg</DT>
<DT><a href="#covid-eu-norm4">Graph 11:</a> <B>Cases</B>: Italy, Greece, Czech Republic, Slovenia, Slovakia, Croatia, Romania, Poland, Hungary, Bulgaria, Serbia</DT>
<DT><a href="#rates-eeu">Graph 12:</a> <B>Increases</B>: Eastern Europe, Daily Increases: Italy, Taiwan</DT>
<DT><a href="#covid-eu-norm5">Graph 13:</a> <B>Cases</B>: Italy, Estonia, Belarus, Lithuania, Latvia, Ukraine, Russia</DT>
<DT><a href="#covid-eu-linear">Graph 14:</a> <B>Cases</B>: Western Europe: Italy, France, Germany, Spain, Switzerland, UK, Netherlands, Sweden</DT>
<DT><a href="#covid-uk">Graph 15:</a> <B>Cases</B>: UK: England Regions</DT>
<DT><a href="#covid-uk-linear">Graph 16:</a> <B>Cases</B>: UK: England Regions</DT>
<DT><a href="#covid-uk-all">Graph 17:</a> <B>Cases</B>: UK: England, Scotland, Wales, Northern Ireland</DT>
<DT><a href="#covid-world">Graph 18:</a> <B>Cases</B>: World: China, Italy, Iran, France, Spain, USA, South Korea, Japan</DT>
<DT><a href="#covid-world-norm">Graph 19:</a> <B>Cases</B>: World: Italy, Iran, France, USA, Australia, South Korea, Singapore, Japan</DT>
<DT><a href="#covid-us-norm">Graph 20:</a> <B>Cases</B>: US States: Italy, Washington, New York, New Jersey, Louisiana, Michigan, Massachusetts, Illinois, Colorado, California, Florida, Texas</DT>
<DT><a href="#covid-world-norm2">Graph 21:</a> <B>Cases</B>: Italy, USA, South Korea, Canada, New Zealand</DT>
<DT><a href="#covid-world-norm3">Graph 22:</a> <B>Cases</B>: Italy, Israel, Pakistan, Turkey, South Africa, Russia, Saudi Arabia</DT>
<DT><a href="#deaths-us">Graph 23:</a> <B>Deaths</B>: Deaths: USA: Italy, France, USA, Germany</DT>
<DT><a href="#covid-world-sa2">Graph 24:</a> <B>Cases</B>: South America (Andean): Italy, Chile, Ecuador, Peru, Bolivia, Argentina</DT>
<DT><a href="#covid-world-sa3">Graph 25:</a> <B>Cases</B>: South America: Italy, Brazil, Colombia, Uruguay, Paraguay, Venezuela</DT>
<DT><a href="#covid-world-ca">Graph 26:</a> <B>Cases</B>: Central America: Italy, Panama, Dominican_republic, Mexico</DT>
<DT><a href="#covid-world-seasia">Graph 27:</a> <B>Cases</B>: South East Asia: Italy, Thailand, Taiwan, Philippines, Vietnam, Cambodia</DT>
<DT><a href="#covid-world-warm">Graph 28:</a> <B>Cases</B>: Warm Countries: Italy, France, USA, Brazil, Australia, Malaysia, Qatar, Thailand, Bahrain, Indonesia, Kuwait, Egypt, India</DT>
<DT><a href="#covid-world-warm2">Graph 29:</a> <B>Cases</B>: Warm Countries: Malaysia, Qatar, Bahrain, Egypt, India, Kuwait</DT>
<DT><a href="#covid-world-linear">Graph 30:</a> <B>Cases</B>: World: China, Italy, Iran, France, USA, South Korea, Japan</DT>
</DL>
<hr><P><h3><a name="covid-eu"></a>Western Europe: Italy, Spain, France, Germany, Netherlands, UK</h3><P>
<img src="29mar2020/covid-eu.png"><P>
<UL>
<LI>The graph shows <B>cumulative number of confirmed cases</b>, plotted on a log
scale, against time. The country curves are shown offset by the
amounts shown. </LI>
<LI>Italy's daily increase rate had been reducing slowly, and is
showing signs that it may be peaking (see Graph 3). Lombardy's
daily increase rate results appeared to have peaked six days ago,
though it ticked back up the last two days. If it hasn't peaked, it
seems like it is close.
<LI>Over the past two weeks France, Germany, the UK, the Netherlands and Spain
all became aligned with the 22 percent daily increase curve
that Italy followed at this point, rather than the higher 35%
curve all the large European countries initially followed.
<LI>France, and the Netherlands appear now to have followed Italy in
dropping off the 22% curve in the last five or six days, and are more
aligned now with the 13% curve that Italy followed for about a week.
<LI>Spain is just starting to shown signs of following the others,
but only today's update reached 13%, which isn't long enough to
establish a new trend.
<LI>For nearly two weeks the UK has been on the 22% daily increase
curve, rather than the 35% daily increase curve it was previously
on. However, see the UK regional graphs for the wide difference
between London and the other regions.
</UL>
<hr><P><h3><a name="covid-eu-norm"></a>Western Europe: Italy, Switzerland, Spain, France, Germany, Netherlands, UK</h3><P>
<img src="29mar2020/covid-eu-norm.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI><I>Commentary updated 30th March 2020</I>
<DL>
<DT>35% daily increase corresponds to a doubling time of 2.5 days</DT>
<DT>22% daily increase corresponds to a doubling time of 3.5 days</DT>
<DT>13.5% daily increase corresponds to a doubling time of 5.5 days</DT>
</DL>
<LI> I'm now showing these countries aligned with the 13.5% curve as
all of them now appear to have left the 22% curve.
<LI> France, Germany and (tentatively) the UK are all now tracking
along the 13.5% daily increase curve that Italy followed.
<LI> Italy has now dropped off of exponential increases and appears to have peaked.
<LI>Switzerland has a relatively small population, and so the number
of cases per million inhabitants is much higher. Switzerland is
shown two days behind Italy and has followed Italy closely for the
last two weeks.
<LI> See the <a href="#deaths-eu-norm">this death rates graph</a> for why I am
not confident in this placement for Switzerland - it appears that
Switzerland is testing more widely than Italy, so Switzerland is
likely to be perhaps as much as 10 days behind Italy.
<LI>Spain stayed at 35% daily increases for much longer than any
other large European country, which caused it to close on Italy,
then followed the 22% curve for a week. Spain is now tracking
along the 13.5% curve, although it joined this curve at roughly
the point where Italy departed it.
</UL>
<hr><P><h3><a name="rates"></a>Western Europe Daily Increases: Italy, Lombardy, France, USA, UK, Spain, Greece, Denmark</h3><P>
<img src="29mar2020/rates.png"><P>
<UL>
<LI>The graph shows <B>daily increase in confirmed cases per million inhabitants</B>, plotted on a log scale, against time.
A Holt-Winters moving average filter with constants α=0.5 and
β=0.5 has been applied to smooth the curves as differences are
very noisy. This is a moderate amount of smoothing and it imposes a
about a days lag, but it does extract trends fairly well. The
curves are not offset, today is Day 0 for all curves.</LI>
<LI>Generally, trends are easier to see on a cumulative plot, as changes are inherently more noisy. However, this view is better to see whether a country has peaked or not.
<LI>The daily increase in cases appears to have peaked in Lombardy, and perhaps in Italy as a whole. The daily increases have decreased for five consecutive days in Lombardy.
<LI>Spain and the US are showing no signs of nearing a peak, whereas France and the UK show slightly sub-exponential increases.
<LI>Denmark and Greece show no clear pattern recently, but neither has peaked yet.
</UL>
<hr><P><h3><a name="deaths-eu-norm"></a>Deaths: Western Europe: Italy, Spain, France, Netherlands, Switzerland, UK, Germany</h3><P>
<img src="29mar2020/deaths-eu-norm.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>deaths per million
inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI> As different countries have different testing policies, many
people have suggested that we should look at deaths instead.
There are several downsides to using deaths as a metric. First,
if the purpose of these graphs is to provide warning of what is
to come, or to verify whether measure are working, deaths is not
very useful. Death rate is too low to provide a warning signal
in advance of there being a problem, and it is not a good early
indicator of whether measures are working because it lags case
data by between one and two weeks. It can, however, provide
some insight into what fraction of infections are being detected
in different countries. Generally, if a country is further
behind in this graph than in the equivalent cases graph, then
the country is probably catching a larger fraction of cases.
This is particularly pronounced in the case of Germany.
<LI>
Death data is also problematic because deaths per day does not
go down quickly when cases go down. This is particularly clear
in the Korean data, where the death rate has remained nearly
constant for three weeks after new infections peaked.
<LI>
Finally, when a healthcare system gets overwhelmed, death rate
goes up from something like 0.9% (Korea) to something like 3-4%
(Hubei, parts of Lombardy).
<LI>
Generally when cases are increasing exponentially, most
countries' death rate curves shadow the cases curve, with a lag
of between 6 (France, UK) and 12 days (Germany). Spain, France,
Netherlands and the UK look very similar to how they looked using
case data around 6 days ago. Germany is about ten days further
back on this graph. The difference in
per-capita testing rates does not seem to explain this
difference.
</UL>
<hr><P><h3><a name="covid-eu-lom"></a>Italy, Lombardy, Switzerland, Austria</h3><P>
<img src="29mar2020/covid-eu-lom.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>I have aligned the 35% daily increase rate parts of the four
graphs, so the points at which they diverge can be seen. As a
result the graph shows Lombardy as being 5.5 days ahead of Italy,
but a more realistic value based on today's data points is seven
days ahead.
<LI>Lombardy now appears to have peaked, though I won't be sure of
this for a few more days. See Graph 3. The daily increase in cases
is today was roughly the same as ten days ago, with a peak five days
ago.
<LI>Switzerland tracked along the 35% curve about six days further
than Italy did, so comparing with Italy as a whole no longer seems
to be the right baseline. The Lombardy results provide a better
new reference curve. Beware though that these time estimates
depend on both Lombardy and Switzerland detecting roughly the same
fraction of cases. Switzerland is only testing severe cases at
this point, and Lombardy was clearly overloaded at the same point.
The death rate in Lombardy at this
point was, however, about four times higher than in Switzerland.
It is risky to read too much into the death rates, but it might
mean that Switzerland is counting a larger fraction of infected
people than Lombardy did at the same point; if so, then
Switzerland is further behind Lombardy than I have suggested. THe
death rate curves in the previous graph certainly suggest this may
be the case.
<LI>Austria has been on the 35% daily increase curve, but the last
five days' increases have been lower. Austria now appears to be
following the Lombardy curve about ten days behind.
</UL>
<hr><P><h3><a name="covid-eu-norm2"></a>Nordic Region: Italy, Iceland, Denmark, Norway, Sweden, Finland, South Korea</h3><P>
<img src="29mar2020/covid-eu-norm2.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Data for most Nordic countries shows large waves of
imported cases, with increase rates above 35%, followed by a
slump as the imports cease. Sometimes this is followed six or so
days later by an echo of the original surge.
<LI>Iceland suffered a large number of imported cases relative
to its very small population. After that burst stopped, Iceland
followed roughly the same curve as Italy, two days ahead. Eight
days ago Iceland's increase rate increased for five days, but it
has now levelled off at a similar rate to Italy. It is possible
that this is due to increased testing rather than a burst in new cases.
<LI>I will discuss Sweden, Denmark, Norway and Finland on the
next graph. Unfortunately the data no longer looks similar to the South
Korean curve.
</UL>
<hr><P><h3><a name="covid-eu-norm2b"></a>Nordic Region (offset curves): Denmark, Norway, Sweden, Finland</h3><P>
<img src="29mar2020/covid-eu-norm2b.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI> These countries experienced a large wave of imported cases.
However, it appears they were effective at contact tracing for
these cases, and most of them were effectively quarantined.
Despite this, it appears a non-negligible number of local
infections escaped detection, and from this smaller base,
exponential growth continued. I have subtracted the amounts
shown from the case counts before plotting - these represent my
guess at the number of imported cases and their immediate
contacts that were stopped by contact tracing. If we subtract
these values, the remaining cases show straight lines at the
characteristic values of 35% or 22%. Am I convinced by these
offset ammounts? No, not completely - see Norway below. But this way of viewing
the data makes more sense to me than the raw counts in the previous
graphs.
<LI>Sweden appeared to be growing exponentially at 35% per day
from a base of about 220 active cases six days ago, but a
sudden change to a 16% daily increase rate occurred five days
ago.
<LI>Finland appears to have been growing exponentially at 22%
per day from a base of about 135 active cases nine days ago. The last three days hint that a change to a lower increase rate similar to Sweden's 16% has occured.
<LI>Denmark was growing exponentially for seven days at 22% per
day from a base of about 185 active cases nine days ago. The last four days Sweden seems to have moved to a lower increase rate similar to Sweden.
<LI>Norway appeared to be growing exponentially at 35% per day
from a base of about 260 active cases six days ago. Norway
also appears to have switched to a 16% daily increase the last
few days.
</UL>
<hr><P><h3><a name="rates-nordic"></a> Nordic Region, Daily Increases: Italy, Denmark, Sweden, Norway, Finland, Iceland, Estonia</h3><P>
<img src="29mar2020/rates-nordic.png"><P>
<UL>
<LI>The graph shows <B>daily increase in confirmed cases per million inhabitants</B>, plotted on a log scale, against time.
A Holt-Winters moving average filter with constants α=0.5 and
β=0.5 has been applied to smooth the curves as differences are
very noisy. This is a moderate amount of smoothing and it imposes a
about a days lag, but it does extract trends fairly well. The
curves are not offset, today is Day 0 for all curves.</LI>
<LI><I>Commentary updated 30 March 2020.</I>
<LI>Generally, trends are easier to see on a cumulative plot, as
changes are inherently more noisy. However, this view is better
to see whether a country has peaked or not.
<LI>Daily increases in absolute numbers have been nearly constant for
several days in Finland and Iceland. This is likely to an indication
that the infection rate in these countries is peaking, though we wont
be sure until it has been going down again for more than a week.
Certainly, exponential growth is no longer occurring in these
countries.
<LI>Norway was growing exponentially until 26th March, but since then
has been decreasing, Three days is not long enough to have confidence
that Norway has peaked, as daily change data is always noisy, but it
hints that it might have done so, especially relatively good news from elsewhere
in the Nordic region.
<LI>Denmark and Sweden have very similar exponential increase rate
profiles for the last two weeks. In both countries there is a hint of
a slow decrease below exponential in the last two days, but it's not a
long enough trend to say anything with confidence.
<LI>Ten days ago, Estonia looked like it had peaked, but this behviour
has happened in other rountries such as Denmark, where a large number
of case are imported. The imported cases are mostly tracked down,
leading to a dip, then growth again as transmission that was missed
grows. The peak the last four days may be an echo of the original
imported peak - this happened in Denmark and Sweden too, though their
echoes were less pronounced.</UL>
<hr><P><h3><a name="covid-eu-norm3"></a>Italy, Belgium, Ireland, Portugal, Luxembourg</h3><P>
<img src="29mar2020/covid-eu-norm3.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>In Belgium, the inital early ramp-up appears to be mostly
due to imported cases from Italian ski resorts. Since these
imports stopped, Belgium seems to be on a similar 22% daily
increase curve to that followed by Italy
<LI>Ireland and Portugal continue to follow the Italian curve closely, about 12 days behind.
<LI>Luxembourg has a very small population, so the curve is
noisy. However, the last ten days data have taken Luxembourg
well above the point Lombardy reached at this stage of the
infection, but the last two datapoints hint at lower increases
around 22% in the future. See the next graph for why I am not
confident Switzerland really is quite so close behind Italy as
this graph would suggest.
</UL>
<hr><P><h3><a name="deaths-eu-norm2"></a>Deaths: Italy, France, Germany, Luxembourg</h3><P>
<img src="29mar2020/deaths-eu-norm2.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Luxembourg is such an outlier in the previous graph that this
leads me to doubt that the confirmed case data is comparable with
other countries. The number of deaths in Luxembourg is very small -
only eight - but it's just enough that we can get a very rough
cross-calibration of case data vs death data. It seems likely that
testing in Luxembourg is much more effective than in France or Italy,
and so is identifying many more people whose symptoms would be too
mild to merit testing in France or Germany. It is clear that there
are a large number of cases in Luxembourg, but not so many more per
million inhabitants as the previous graph shows. It looks like deaths
lag case data by about ten days more in Luxembourg than in France.
The German data shows a similar additional lag.
</UL>
<hr><P><h3><a name="covid-eu-norm4"></a>Italy, Greece, Czech Republic, Slovenia, Slovakia, Croatia, Romania, Poland, Hungary, Bulgaria, Serbia</h3><P>
<img src="29mar2020/covid-eu-norm4.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI> Most Eastern European countries have shown large downturns. This logscale plot of cumulative confirmed cases no longer gives enough visibility into what is happened. See the next graph for a better view.
</UL>
<hr><P><h3><a name="rates-eeu"></a>Eastern Europe, Daily Increases: Italy, Taiwan</h3><P>
<img src="29mar2020/rates-eeu.png"><P>
<UL>
<LI>The graph shows <B>daily increase in confirmed cases per million inhabitants</B>, plotted on a log scale, against time.
A Holt-Winters moving average filter with constants α=0.5 and
β=0.5 has been applied to smooth the curves as differences are
very noisy. This is a moderate amount of smoothing and it imposes a
about a days lag, but it does extract trends fairly well. The
curves are not offset, today is Day 0 for all curves.</LI>
<LI><I>Updated 29th March</I>
<LI>Generally, trends are easier to see on a cumulative plot, as
changes are inherently more noisy. However, this view is better
to see whether a country has peaked or not.
<LI>I thought Slovakia had peaked a few days ago, but it appears I was
wrong. Nevertheless, growth there is almost constant, and certainly
no longer exponential.
<LI>Greece, Bulgaria, Hungary and perhaps Poland appear to be close to
peaking - the daily increase has been nearly constant for a number
of days, and they no longer shows signs of exponential growth.
<LI>Slovenia and Romania are still growing exponentiall, though with a
relatiively low daily increase rate.
<LI>I have added Belarus to this graph, as the curve is intereting.
Belarus definitely seems to have peaked a week ago, though the
absolute values are so small - only 94 cases in total - that only a
small undetected outbreak could reverse this trend.</UL>
<hr><P><h3><a name="covid-eu-norm5"></a>Italy, Estonia, Belarus, Lithuania, Latvia, Ukraine, Russia</h3><P>
<img src="29mar2020/covid-eu-norm5.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Estonia's small population and recent fast ramp up of cases
means it now has a high number of cases per million inhabitants. The
current dip may be due to the end of a wave of imported cases, as
seen in the Danish data.
<LI>Belarus and Lithuania have too few cases for the current trend
lines to be clear. With the exception of the most recent datapoint,
they appear to be very roughly following the 35% curve, or a little
higher.
<LI>Russia is experiencing a lower daily increase rate than most
northern countries at the equivalent stage of the infection. I've aligned it with the 22% daily increase
curve that many countries followed.
<LI>Latvia also appears to be roughly following the 22% daily increase curve.
</UL>
<hr><P><h3><a name="covid-eu-linear"></a>Western Europe: Italy, France, Germany, Spain, Switzerland, UK, Netherlands, Sweden</h3><P>
<img src="29mar2020/covid-eu-linear.png"><P>
<UL>
<LI>The graph shows <b>number of confirmed cases</b>, plotted on a
linear scale, against time. The country curves are shown offset
by the amounts shown.</LI>
<LI>I normally use a log scale on the y-axis because
exponential growth gives a straight line on a log-linear graph.
This allows exponential growth rates to be compared. However,
many readers don't like log-linear graphs, so this one is for
them. It has to be truncated, or you cannot see any information.
It doesn't really show anything additional over the log graphs,
except it looks scarier.
</UL>
<hr><P><h3><a name="covid-uk"></a>UK: England Regions</h3><P>
<img src="29mar2020/covid-uk.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>All the English regions converged onto the 35% daily increase
curve that Italy followed, and appear now to be starting to transition
to the 22% daily increase curve.
<LI>London is running around a week ahead of the UK, and is tracking
along the curve that Lombardy followed. Unlike France and Germany,
the UK government was slow to impose stringent isolation measures;
indeed they are still not as strict as elsewhere in Europe.
</UL>
<hr><P><h3><a name="covid-uk-linear"></a>UK: England Regions</h3><P>
<img src="29mar2020/covid-uk-linear.png"><P>
<UL>
<LI>The graph shows <b>number of confirmed cases</b>, plotted on a
linear scale, against time. The country curves are shown offset
by the amounts shown.</LI>
<LI>The main reason to include this graph is that it shows much much
further London has to go if it follows Lombardy.
</UL>
<hr><P><h3><a name="covid-uk-all"></a>UK: England, Scotland, Wales, Northern Ireland</h3><P>
<img src="29mar2020/covid-uk-all.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>England (excluding London), Scotland, Wales and Northern Island
are all experiencing daily increase rates close to or below the 22%
curve that Italy followed.
</UL>
<hr><P><h3><a name="covid-world"></a>World: China, Italy, Iran, France, Spain, USA, South Korea, Japan</h3><P>
<img src="29mar2020/covid-world.png"><P>
<UL>
<LI>The graph shows <B>cumulative number of confirmed cases</b>, plotted on a log
scale, against time. The country curves are shown offset by the
amounts shown. </LI>
<LI> The early part of the China curve is shown for
comparison. I'm not sure how accurate the numbers are in the
early stage because they didn't initially know what to look for,
and the way of measuring changed part way through this period.
The initial increase rate is fairly consistent with the 35% daily growth seen in
Europe.
<LI>Other than China, South Korea is the only country to have had a
high sustained increase rate, and then bring the virus under
control.
<LI>The USA had been tracking very closely along the 35% growth
line, and has done so for much longer than any other
country. Testing in the US was initially very limited, but
recently it seems testing has been catching up somewhat. In the
last few days the US has shown the first signs of dropping off of
the 35% daily increase curve.
<LI>Cases in the US are concentrated in a few states, in a
similar way to how cases in Italy are concentrated in
Lombardy.
<LI>Iran tracked a little above a 35% increase rate until three
weeks ago. Since then, Iran had experienced ten days of
consistent 11.5% exponential growth, with the last ten days
showing further decline. For many days the daily increase in
cases had been roughly constant at around 1100-1200 new cases per
day, but it has now started to increase again. It is possible
this was due to limitations in testing.
<LI>Japan is an enigma. The testing rate there is low, so cases
may be being underreported. However consistently missing the
same fraction of cases would not affect the exponential growth
doubling time, which had been extremely consistent at 8.5% per
day for many weeks, until the last week when it has declined
further. It seems more likely that early measures taken there
are being effective at reducing the increase rate, but are not
sufficient to avoid exponential growth altogether. It looks like
the combination of early school closure, plus ubiquitous face
masks and regular Japanese good hygene may be responsible for
Japan's unique track. No-one really knows,
but <a href="https://www.japantimes.co.jp/opinion/2020/03/21/commentary/japan-commentary/japan-still-coronavirus-outlier/#.XnZH06FRUlQ">many
are speculating.</a>
</UL>
<hr><P><h3><a name="covid-world-norm"></a>World: Italy, Iran, France, USA, Australia, South Korea, Singapore, Japan</h3><P>
<img src="29mar2020/covid-world-norm.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI> Showing cases per million inhabitants does not greatly change
the overall picture compared to the previous graph.
<LI>In this view, the US moves a few days further behind Italy. This
is probably deceptive, and it might be better to show data for
New York State, for example, on this graph.
<LI>I've added a curve for Singapore, which contained the initial
imported cases very well. The graph shows a worrying slow but
steady super-exponential growth recently though, perhaps indicating
that current measures are starting to not be effective, or that more
cases are being imported again. I've been told that most of the new
cases are imports; it makes sense that if Singapore's quarantining
of visitors and contact tracing is mostly keeping on top of local
spread, then as the pandemic ranges worldwide, Singapore will see an
equivalent rise in imported cases. The number of untraced cases remains small at this time.
</UL>
<hr><P><h3><a name="covid-us-norm"></a>US States: Italy, Washington, New York, New Jersey, Louisiana, Michigan, Massachusetts, Illinois, Colorado, California, Florida, Texas</h3><P>
<img src="29mar2020/covid-us-norm.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>I am now pulling data for this graph from
the <a href="https://github.com/nytimes/covid-19-data">NYT
dataset</a>, which is much less noisy than the JHU dataset I was
previously using.
<LI>Most US states are a long way behind European countries, but
several now have comparable rates per million inhabitants and New
York is ahead. I have plotted the states with most confirmed
cases.
<LI>European countries moved from a 35% daily increase curve to a
22% daily increase curve; Washington is one of the few US states
to have clearly made a similar transition, and in the last few
days the daily increase rate has declined further. Washington is
the only US state with a large number of cases to start to turn
the tide significantly.
<LI>New York was growing at close to the 35% daily increase rate
seen in Europe, but then had very large increases over a week.
This usually happens when cases have been spreading undetected,
and suddenly testing starts catching up. The last few days, cases
in NY have been growing exponentially at around 22% per day. This
is the same growth curve most European countries followed once
people started to get concerned about COVID19. I have placed New
York so as to align it with the 22% curve. This places it 4 days
offset from Italy, but today's datapoint would place New York
above Italy. As Italy seems to have peaked and New York has more
cases per head of population than Italy, it makes no sense saying
where New York is on Italy's track: New York is forming its own
track.
<LI>Illinois and California are the other two states that are now
following the 22% curve. California has followed the curve for
some time, but Illinois has only recently come out of fast growth
(presumably due to testing catching up somewhat) so we will have
to wait and see it it stabilizes along this curve.
<LI>New Jersey, Louisiana, Michigan, Colorado, Florida, and Texas
have been increasing recently at close to the 35% daily increase
rate seen in Europe, so I've placed then on that curve, though
this gives misleading time delays relative to Italy. Based on the
most recent data point, New Jersey is 12 days behind Italy.
</UL>
<hr><P><h3><a name="covid-world-norm2"></a>Italy, USA, South Korea, Canada, New Zealand</h3><P>
<img src="29mar2020/covid-world-norm2.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Canada has been tracking along the 35% daily increase curve that
most other countries have followed before social isolation measures
were introduced, started on a downturn, then had a big step increase.
I'm told this is likely to be due to a large number of people
returning from spring break in the US.
<LI>New Zealand is proceeding along the 35% daily increase curve with
remarkable accuracy, and has just passed the point where the increase rate started to reduce in Italy.
</UL>
<hr><P><h3><a name="covid-world-norm3"></a>Italy, Israel, Pakistan, Turkey, South Africa, Russia, Saudi Arabia</h3><P>
<img src="29mar2020/covid-world-norm3.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Canada has been tracking along the 35% daily increase curve that most other countries have followed before social isolation measures were introduced, but is showing a lower increase rate the last four days.
<LI>Israel's lower increase a week ago turned out to be a false hope, as they moved back to tracking just below the 35% curve afterwards.
<LI>Chile and New Zealand appear to be roughly following the 35% daily increase curve.
<LI>Pakistan has seen very rapid rises, but is now converging on the 35% daily increase curve about 28 days behind Italy.
</UL>
<hr><P><h3><a name="deaths-us"></a>Deaths: USA: Italy, France, USA, Germany</h3><P>
<img src="29mar2020/deaths-us.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>deaths per million
inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Confirmed cases in the US have been growing very fast recently.
The US testing procedures were very slow to get started, but are
reported to have scaled up quickly. How much of the rapid increase in
case data is due to this scale-up? This graph shows the US death
rate, with Italy and France for comparison. When looking at confirmed
cases, the US is roughly 15 days behind Italy, whereas when looking at
death rates, the US is roughly 19 days behind Italy. This probably
indicates that a small part of the recent increases is indeed due to
improved testing, but the difference is nowhere near as large as
Germany or Luxembourg, so the underlying infection rate must also be
high. If this gap widens in the future, then this would be evidence
that testing is getting ahead of the epidemic.
<LI> To put this in perspective if Italy is identifying just the ~10% of infections that need ICU care, the US is probably identifying very roughly ~30% of infections. (1.35 ^ 4 ~= 3)
</UL>
<hr><P><h3><a name="covid-world-sa2"></a>South America (Andean): Italy, Chile, Ecuador, Peru, Bolivia, Argentina</h3><P>
<img src="29mar2020/covid-world-sa2.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Data on this graph comes directly from the <a
href="https://github.com/CSSEGISandData/COVID-19/tree/master/csse_covid_19_data">JHU
dataset</a>, or from the Wikipedia dataset which is often better
quality. I have not double-checked the data, and it may lag by up to
a day.
<LI>South American countries seem to be clustered into two: Andean
states except for Columbia have recently been tracking roughly along
the 22% daily increase curve, roughly following the track taken by
Italy.
<LI>Cases in Ecuador were increasing significantly faster than 35% per
day until a week ago. This usually indicates that the epidemic has
spread without being detected, and testing is now catching up. For
the last week, increase rates declined significantly, to less than
15%.
</UL>
<hr><P><h3><a name="covid-world-sa3"></a>South America: Italy, Brazil, Colombia, Uruguay, Paraguay, Venezuela</h3><P>
<img src="29mar2020/covid-world-sa3.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Data on this graph comes directly from the <a
href="https://github.com/CSSEGISandData/COVID-19/tree/master/csse_covid_19_data">JHU
dataset</a>, or from the Wikipedia dataset which is often better
quality. I have not double-checked the data, and it may lag by up to
a day.
<LI>South American countries seem to be clustered into two: Andean
states except for Columbia have recently been tracking roughly along
the 22% daily increase curve, roughly following the track taken by
Italy. The rest of South America seems to be fairing considerably better, with lower overall numbers of cases and lower increase rates. Growth is still exponential though.
</UL>
<hr><P><h3><a name="covid-world-ca"></a>Central America: Italy, Panama, Dominican_republic, Mexico</h3><P>
<img src="29mar2020/covid-world-ca.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Data on this graph comes directly from the <a
href="https://github.com/CSSEGISandData/COVID-19/tree/master/csse_covid_19_data">JHU
dataset</a>, or from the Wikipedia dataset which is often better
quality. I have not double-checked the data, and it may lag by up to
a day.
<LI>Panama, Mexico and the Domincan Republic all seem to be following
the track paved by Italy, though they are at different stages along
this track.
<LI>In part, the reason Mexico is further behind is simply because it
has a larger population; as the outbreak is not evenly distributed,
this may underplay the severity in the outbreak clusters.</UL>
<hr><P><h3><a name="covid-world-seasia"></a>South East Asia: Italy, Thailand, Taiwan, Philippines, Vietnam, Cambodia</h3><P>
<img src="29mar2020/covid-world-seasia.png"><P>
<UL>
<LI>The graph shows cumulative number of <B>confirmed cases per million inhabitants</B>, plotted on a log scale, against time. The
country curves are shown offset by the amounts shown.</LI>
<LI>Data on this graph comes directly from the <a href="https://github.com/CSSEGISandData/COVID-19/tree/master/csse_covid_19_data">JHU dataset</a>. I have not double-checked the data, and it may lag by up to a day.
<LI>I have included a graph for Vietnam, Cambodia, Taiwan and the Philippines, not because the situation there is bad (they all have a few weeks lead time to prepare), but because the trend for each has recently started to look worrying.
</UL>
<hr><P><h3><a name="covid-world-warm"></a>Warm Countries: Italy, France, USA, Brazil, Australia, Malaysia, Qatar, Thailand, Bahrain, Indonesia, Kuwait, Egypt, India</h3><P>
<img src="29mar2020/covid-world-warm.png"><P>
<UL>
<LI>The graph shows <B>cumulative number of confirmed cases</b>, plotted on a log
scale, against time. The country curves are shown offset by the
amounts shown. </LI>
<LI>Very few warm countries have enough cases to establish a clear
increase rate trend. The graph shows number of confirmed case for
some typical "cool" countries and some "warm" ones. During the
timescale shown, Spain had experienced cool weather.
<LI>Malaysia, India, Bahrain, Kuwait and Egypt are all warm countries and have all been experiencing
roughly 14% daily growth.
<LI>Australia used to be on the 14% curve, but ten days ago it
switched to the 22% curve. The results from ten days ago correspond
to infections from roughly 17-20 days ago. The mean daytime
temperature in Sydney for the five days before March 3rd (17 days
ago) was 28.6C, whereas for the five days after March 3rd it was
23.8C. More analysis is needed to know if this is significant.
<LI>Malaysia had a large increase four days ago, but since seems to be tracking close to 14%.
<LI>Brazil seems to be tracking roughly along the 35% line, which seems to run counter to warm weather inhibiting the spread of the virus.
<LI> Both Qatar and Bahrain have very low recent increase
levels. This may indicate that most cases were imports, and that
local spread has been effectivel contained.
<LI>Although Singapore has a warm climate, I have ommited it from
this graph, because strong contact tracing there dwarfs any
climate-dependent effect we might observe.
<LI> In general, it does appear that COVID19 may spread more slowly in warm climates, but the evidence is inconclusive, with Brazil being the main counterexample.
</UL>
<hr><P><h3><a name="covid-world-warm2"></a>Warm Countries: Malaysia, Qatar, Bahrain, Egypt, India, Kuwait</h3><P>
<img src="29mar2020/covid-world-warm2.png"><P>
<UL>
<LI>The graph shows <B>cumulative number of confirmed cases</b>, plotted on a log
scale, against time. The country curves are shown offset by the
amounts shown. </LI>
<LI> The graph shows number of confirmed cases per million
inhabitants, plotted on a log scale, against time. The country
curves are shown offset by the amounts shown.
<LI>This graph shows the same warm countries as the previous graph.
<LI>Australia had been tracking along the 14% curve, but the last few day this has increased to 25% daily increase per day. Australia has been cooler recent as it moves into Autumn.
<LI>In general, all the warm country data is quite noisy. Partly this is due to there being few cases in each country. All these countries are showing a lower average increase rate to that see in Europe or the US.
</UL>
<hr><P><h3><a name="covid-world-linear"></a>World: China, Italy, Iran, France, USA, South Korea, Japan</h3><P>
<img src="29mar2020/covid-world-linear.png"><P>
<UL>
<LI>The graph shows <b>number of confirmed cases</b>, plotted on a
linear scale, against time. The country curves are shown offset
by the amounts shown.</LI>
<LI>In the other graphs I use a log scale on the y-axis because
exponential growth gives a straight line on a log-linear graph, and this makes changes in the growth rates visible and allows exponential growth rates to be compared. However, many
readers have told me they don't like log-linear graphs, so this one is for them. It
has to be truncated, or you cannot see any information. It
doesn't really show anything additional over the log graphs,
except it looks scarier and shows how much worse things are set to get if effective measures are not taken.
<LI>I have shown the China curve until the daily increase rate
drops below 0.1%. The glitch in the center of this curve is a
change in measurement methodology. If Italy followed a similar
curve, this wave of the epidemic may have abated in 30 days time,
but this prediction should be tempered by the fact that Italy has
not quite reached the logistics curve inflection point, though it
appears to be close. On this basis, because deaths lag infections
by 1-2 weeks, the worst is yet to come for many Italian hospitals.
<LI>One thing this view shows well is how much of an outlier the US
is - the faster increase rate of the US
curve is self-evident. The US exceeded both China and Italy's
case counts today.
<LI>This view also makes clearer the recent restart of exponential
growth in Iran. It is unclear to me whether exponential growth
actually had previously stopped in Iran, or whether the increase
rate was simply limited by their testing capacity. If it was the
latter, then something about their process for confirming cases has
changed.
</UL>
<hr>
<h3>Thoughts</h3>
<P>
While you're sitting pondering your mortality, think how astounding it is that one single viral particle from a bat can replicate so far, so fast, and cause so much trouble! Biology is truly amazing!
</P>
<h3>FAQ</h3>
<P><B>Q: Where does the data come from?</B>
<P>Where possible, the data comes from the relevant national
authorities, as they tend to be more up to date. In some cases I'm
using
the <a href="https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports">WHO
daily briefing</a>, but they lag the national authorities somewhat.
The <a href="https://en.wikipedia.org/wiki/2019%E2%80%9320_coronavirus_pandemic">wikipedia
pages</a> contain links to the national authorities. Some are
<a href="https://thl.fi/en/web/infectious-diseases/what-s-new/coronavirus-covid-19-latest-updates">Finland</a>,
<a href="https://www.santepubliquefrance.fr/maladies-et-traumatismes/maladies-et-infections-respiratoires/infection-a-coronavirus/articles/infection-au-nouveau-coronavirus-sars-cov-2-covid-19-france-et-monde">France</a>,
<a href="https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Fallzahlen.html">Germany</a>,
<a href="https://www.gov.ie/en/news/7e0924-latest-updates-on-covid-19-coronavirus/">Ireland</a>,
<a href="https://www.fhi.no/sv/smittsomme-sykdommer/corona/dags--og-ukerapporter/dags--og-ukerapporter-om-koronavirus/">Norway</a>
<a href="https://www.moph.gov.qa/english/Pages/Coronavirus2019.aspx">Qatar</a>,
<a href="https://www.gov.si/teme/koronavirus/">Slovenia</a>,
<a href="https://www.cdc.go.kr/board/board.es?mid=a30402000000&bid=0030">South Korea</a>,
<a href="https://www.mscbs.gob.es/profesionales/saludPublica/ccayes/alertasActual/nCov-China/situacionActual.htm">Spain</a>,
<a href="https://www.bag.admin.ch/bag/en/home/krankheiten/ausbrueche-epidemien-pandemien/aktuelle-ausbrueche-epidemien/novel-cov.html">Switzerland</a>,
<a href="https://www.gov.uk/guidance/coronavirus-covid-19-information-for-the-public">UK</a>,
<P><B>Q: Can I have your data?</B>
<P>My data is <a href="https://github.com/mhandley/COVID19/">on github</a>..
<P>A more complete dataset is the <a href="https://github.com/CSSEGISandData/COVID-19/tree/master/csse_covid_19_data/csse_covid_19_time_series">Johns Hopkins</a> one. It tends to lag the national data sources and the WHO, but it is complete and machine readable.
<P><B>Q: Can I use your graphs?</B>
<P>
Yes, they're under a CC0 "No rights reserved" license. You can
use them for any purpose. I'd prefer you link back here though,
as the explanations add important context.
<P><B>Q: Different countries are testing at different rates. How can you compare the data?</B>
<P>So long as the fraction of actual cases being detected does
not change, this does not affect any inference we can make about
the growth rate. 35% growth is still 35% growth, whether we
measure 100% of the cases or 50%.
<P>If, for example, Italy is detecting 50% of the cases and the
US is detecting 25% of cases, this affects any predictions of how
far the US is behind Italy At 35% growth, cases double every 2.5
days, so this undersampling would show the US 2.5 days further
behind than it really is.
<P>Likely no-one except Korea and Singapore are getting close to
100% of cases. Probably everyone is detecting at least 20% of
cases, because those require medical attention. We don't really
know what fraction of cases are missed, but the difference in
sampling between countries might skew the delays by a few days in
either direction.
<P><B>Q: Comparing with Italy as a whole is flawed. Shouldn't you be comparing with Lombardy?</B>
<P>Perhaps. Certainly cases in Italy are concentrated in the
North at the moment. Lombardy is running about seven days ahead
of the rest of the country, as measured by cases per million
inhabitants. I've shown this in <a href="#g3">graph 3</a>. The
problem is that cases in some other countries, notably France,
Spain and the USA, are also concentrated, so comparing these
entire countries with Lombardy is biased in the other direction.
These graphs give a crude indication, but they're never going to
be able to track problems down to the local level, where an
individual town is overwhelmed by cases before this becomes
commonplace in a country. Just remember, to compare with
Lombardy, a rough approximation is to move the Italy curve seven days
to the right.
<P><B>Q: Shouldn't you break out China by province?</B>
<P> At the moment I'm only showing China on the graphs that show
absolute counts, not counts per million inhabitants. As the vast
majority of Chinese cases were in Hubei, there's not a great deal
of difference on these graphs between showing Hubei and showing
all of China. The population of Hubei provice is around 57
million, which is roughly the same as Italy. Thus the data for
China is reasonably comparable with the data for Italy.
<P>
The Chinese data is somewhat suspect in the early days, so it's not
very good for comparison until the epidemic gets a fair way along.
Mostly I'm using Italy to provide a model for how other places
might progress, as it's a better fit. But as of March 16th, I've
changed the last (linear) graph to use the Chinese data to show one
possible direction that Italy might folliow.
<P>
Elsewhere in China, cases that arose were stamped on quickly, and
pretty much all of China shut down until that was complete. In
Europe we failed to learn from that model, so we're all much
further along than Beijing, Shanghai, or similar provinces ever
got.
<P><B>Q: Why didn't you show my country?</B>
<P>A1. Until the number of cases reaches around 100, the data
tends to be too noisy to draw conclusions
<P>A2. The graphs are pretty cluttered as it is.
<P>A3. I'll add more as I find time.
<P><B>Q: You aren't an epidemiologist. Why should I listen to you?</B>
<P>You probably shouldn't. I'm a computer scientist and I've
spend decades analysing data, but you should talk to a real
epidemiologist if you want to understand the underlying causes.
Computer scientists do know a lot about exponential growth though.
<P><B>Q: I'm a journalist. Will you appear on my TV show?</B>
<P>No. You should have a real epidemiologist on your TV show.
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<P>
Mark Handley, UCL.
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