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| Main Street, Israel April 16 |
Epidemic
In this issue we summarise the standing of the coronavirus pandemic as it enters its main stage.
While the countries in Europe and North America that were prominent in the first stage have declining daily cases, the focus of the epidemic is now in South America. In a few weeks it will move into South Asia and the Middle East/Arab States/Caucasus in force, where we will see the heaviest numbers, if they can be tested. Finally, sub-Saharan Africa and rural areas will suffer.
In general, the timing of the epidemic in different places has corresponded to the general level of global connectedness of these countries or sub-areas.
Worldwide cases
At the moment we have for each continent
Total cases
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New cases
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Total deaths
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Active cases
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Serious
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Europe
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2056740
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17003
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177333
|
826131
|
7427
|
North America
|
2182001
|
28139
|
132030
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1182030
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19470
|
South America
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1033414
|
46339
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46123
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497870
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11695
|
Asia
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1282418
|
32334
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33358
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471828
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14549
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Africa
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173451
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7648
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4743
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91653
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450
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Oceania
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8861
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13
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131
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469
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2
|
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| Figure. New cases and total cases % by continent, 4 Jun. |
The chart shows that while two-thirds of total cases are Europe and North America, only a third of new cases are in the Highly Industrialised Countries, as the pandemic moves into the developing world.
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| Note- a number of places do not collect data at weekends, hence the periodicity in daily figures Source: Worldometer |
New cases and daily deaths show that while new cases were flat from early April - probably because only a fixed number of tests could be deployed daily at capacity - deaths were steadily falling (down to about half the maximum rate) because distancing was working. However, now we are moving into the main stage of the pandemic as populous middle income countries become involved, and both cases and deaths have started rising again.
Of closed cases - 11% have resulted in death (showing the heavy loading of testing in early stages of the pandemic toward critical cases). Of currently active cases, only 2% are serious - since more general testing is now picking up five times as many less serious cases.
The number of serious and critical cases stayed more or less steady at 50,000 to 60,000 from about 12 April, but is starting to rise again.
The number of serious and critical cases stayed more or less steady at 50,000 to 60,000 from about 12 April, but is starting to rise again.
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Countries - deaths
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| Daily deaths by country 4 June, number of days since 10 deaths. Source Our World In Data. |
The chart shows the progress of daily deaths for the major countries on a logarithmic scale, with the time scale adjusted for comparability. Several types of epidemic progress are in evidence. Typical examples of each epidemic progress are as follows:
- Highly infected countries past the peak, where cases and deaths are falling only slowly -US, UK, Spain, Italy, France, Germany, Sweden
- Countries where the epidemic is still forming - Brazil, India, Peru, South Africa
- Countries that managed to flatten the curve by rapid action, but have not suppressed the epidemic - Philippines
- Countries that have suppressed the epidemic - South Korea, Australia, Brunei, Austria.
The main medium income countries had some time to institute lockdowns, and in the early phase their rate of growth was only about 2/3 that of the HIC, It is possible their younger populations contributed to the slower spread. However their pandemic did not peak after 30 days. Brazil is about to take the lead in daily deaths and India and Peru are bypassing the European countries.
The Philippines intervened forcefully and has held cases and deaths down to a low level, but it has probably lost the fight as it emerges from lockdown..
The Philippines intervened forcefully and has held cases and deaths down to a low level, but it has probably lost the fight as it emerges from lockdown..
Other countries that intervened early enough and consistently have managed to drive the death rate down almost to zero - Australia, South Korea, Austria, Japan, Ireland. However - small bubbles still continue to form, and incoming residents are often infected and have to be quarantined.
Daily cases
The pattern for daily new cases is similar to daily deaths, but numbers are 10 to 100 times as large. Daily cases are also affected by the level of testing, which has not been conducted consistently during the epidemic time frame. Almost everywhere testing started only with the severe cases and eventually proceeded to those with only moderate symptoms, many of whom do not have COVID.Nevertheless the general shape of daily cases is much the same in any country, just sharper, several weeks earlier, and does not decline as rapidly past the peak.
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| Australia - Class 1 |
'Class 1' Countries like Australia with a successful lockdown where the virus was suppressed had the ideal trajectory, with new cases going down exponentially almost as fast as they went up, forming a bell curve.
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| Italy - Class 2 |
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| New York and USA - Class 3 |
Success of social distancing policies
The news is mostly bad - it seems that those who said you could not eliminate the disease may have been right after all. A few islands are disease-free as long as they keep their doors closed. Of countries that actually had an epidemic, only New Zealand and Brunei seem to have eliminated the virus.
Parts of Australia and China are also free of the disease and both seem headed for elimination. Australia gets most of its cases from returning residents, and only 21 cases are hospitalised now (only two are in ICU, none ventilated). The odd cluster keeps popping up so COVID is still in the community, in small numbers.This has been going on for six weeks now.
For the rest, the two methods of suppressing the disease - lockdown, and test-trace-isolate - appear to move towards a steady state. When this is reached. the disease is not eliminated but new cases coast along around some fixed level. This has also happened in those countries who did not lock down or left it too late. The size of that fixed level depends on how soon and how well the countries acted.and executed their intention. Even with a locked down population, the steady leakage from that lockdown due to essential workers.
Most countries are coming out of lockdown without a plan and for no sensible reason, just as they went into it for no sensible reason.
Parts of Australia and China are also free of the disease and both seem headed for elimination. Australia gets most of its cases from returning residents, and only 21 cases are hospitalised now (only two are in ICU, none ventilated). The odd cluster keeps popping up so COVID is still in the community, in small numbers.This has been going on for six weeks now.
For the rest, the two methods of suppressing the disease - lockdown, and test-trace-isolate - appear to move towards a steady state. When this is reached. the disease is not eliminated but new cases coast along around some fixed level. This has also happened in those countries who did not lock down or left it too late. The size of that fixed level depends on how soon and how well the countries acted.and executed their intention. Even with a locked down population, the steady leakage from that lockdown due to essential workers.
Most countries are coming out of lockdown without a plan and for no sensible reason, just as they went into it for no sensible reason.
Plateau levels
Here are a few fixed levels of new cases per day that have been achieved. Deaths per day are moving towards a steady fraction of this limit.
Plateau levels
Here are a few fixed levels of new cases per day that have been achieved. Deaths per day are moving towards a steady fraction of this limit.
NO LOCKDOWN OR FORMAL TRACING cases per day
Belarus 900 Sweden 520
HEAVILY INFECTED, LOCKDOWN cases per day
Still falling slowly
UK 1800 Germany 450 Italy 450 Spain 540 Ukraine 470 Poland 400 Portugal 240 Romania 200 Belgium 170 Netherlands 140, Czechia 60, Serbia 50, Ireland 45 Denmark 42
SUPPRESSED, LOCKDOWN cases per week
Austria 200, Hungary 120, Bulgaria 120, Israel 110, Norway 100, Australia 80, Cuba 75, Estonia 45, China 40, Greece 40, Thailand 30, Jamaica 25, Slovakia 12, Slovenia 4 Mauritius 3 Taiwan 2
In Australia most of the cases are returning residents or associated cases, but still about 14 cases from unknown sources have been popping up per week. New cases can now come from anywhere in the world - four new cases in Western Australia were a family arriving from Sudan.
NEVER REALLY HAD AN EPIDEMIC Occasional cases
Vietnam Cambodia Laos Mongolia, Papua Fiji Timor, Seychelles Comores, Belize Bahamas Liechtenstein.
In the second country to be infected, Iran, lockdown was not comprehensively implemented. New cases fell quickly, almost like a Class 1 country, until bottoming out on 4 May at about 1000 cases a day, at a third of the peak. However then they began to rise again and in a month the country has reached new highs, losing all the prior effort of restraining the virus.
No other country has yet had a true 'second wave' like Iran, but there are ominous signs elsewhere. In Singapore the disease ran away after being kept at low levels for a month. There are several other examples - Korea is starting to get some clusters again, with daily cases rising to about 50 after a month at 10 per day,
Coming out of restrictions is also expected to lead to fresh outbreaks. Israel was running along at about 25 cases a day, down from a peak of about 800. It re-opened schools and reduced restrictions, from 21 April, accompanied by a step-up in testing to 20,000 per day. Social distancing and wearing masks remained in place. However, by May 1 cases were rising to 50 and they are now about 100 per day.
The Philippines also looks to be breaking out just as the country is re-opening, with daily cases rising to 800 after being steady at 200-300 a day for six weeks.
Another metastudy commissioned by the WHO looked at the relative infectivity of distancing in SARS., MERS and COVID. They found that while there had been no randomised trials, the evidence suggested that being close to an infected person had about a 15% chance of infection, about the same as SARS. Staying over 1m away has only a 2.5% chance of infection. Having a face mask had a similar effect.
HEAVILY INFECTED, LOCKDOWN cases per day
Still falling slowly
UK 1800 Germany 450 Italy 450 Spain 540 Ukraine 470 Poland 400 Portugal 240 Romania 200 Belgium 170 Netherlands 140, Czechia 60, Serbia 50, Ireland 45 Denmark 42
ELIMINATED
New Zealand, Brunei
SUPPRESSED, LOCKDOWN cases per week
Austria 200, Hungary 120, Bulgaria 120, Israel 110, Norway 100, Australia 80, Cuba 75, Estonia 45, China 40, Greece 40, Thailand 30, Jamaica 25, Slovakia 12, Slovenia 4 Mauritius 3 Taiwan 2
In Australia most of the cases are returning residents or associated cases, but still about 14 cases from unknown sources have been popping up per week. New cases can now come from anywhere in the world - four new cases in Western Australia were a family arriving from Sudan.
NEVER REALLY HAD AN EPIDEMIC Occasional cases
Vietnam Cambodia Laos Mongolia, Papua Fiji Timor, Seychelles Comores, Belize Bahamas Liechtenstein.
The infection resumes
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| Iran |
No other country has yet had a true 'second wave' like Iran, but there are ominous signs elsewhere. In Singapore the disease ran away after being kept at low levels for a month. There are several other examples - Korea is starting to get some clusters again, with daily cases rising to about 50 after a month at 10 per day,
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| Israel |
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| Philippines |
The Philippines also looks to be breaking out just as the country is re-opening, with daily cases rising to 800 after being steady at 200-300 a day for six weeks.
Some notes on infectivity
It appears the numbers of symptomless cases are much lower than some have expected - only about 15% of cases have no symptoms. This is a far cry from the 96% of undetected cases claimed by Sweden. As with many viruses, the presymptomatic are a much greater risk than the asymptomatic, as people can be highly infectious in the few days before the disease presents itself.Another metastudy commissioned by the WHO looked at the relative infectivity of distancing in SARS., MERS and COVID. They found that while there had been no randomised trials, the evidence suggested that being close to an infected person had about a 15% chance of infection, about the same as SARS. Staying over 1m away has only a 2.5% chance of infection. Having a face mask had a similar effect.
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