Difference between revisions of "Coronavirus"

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</ref> suggest that, with no action by governments, the Coronavirus would kill around 2 million people in the US and half a million in the UK.  
 
</ref> suggest that, with no action by governments, the Coronavirus would kill around 2 million people in the US and half a million in the UK.  
 
With drastic measures to suppress spread of the virus the death toll could have been kept to below 20,000 in Britain (the researchers didn't publish figures for the USA).
 
With drastic measures to suppress spread of the virus the death toll could have been kept to below 20,000 in Britain (the researchers didn't publish figures for the USA).
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== What makes the big difference in numbers? ==
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[[File:COVID-19 mitigation scenarios for GB -- Imperial.jpg | right | thumb | 640px | The flat red line is the capacity of the health system to cope with critical care patients]]
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The Imperial College researchers modelled various scenarios for mitigating the spread of the disease, aiming to find a strategy which kept the numbers of people so badly affected that they need hospital treatment within the resources of the health system to treat them. Put bluntly, without hospital treatment, and especially without the availability of ventilators to assist breathing, most people who need treatment will die. With treatment about half will survive.
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The model showed that none of the mitigation strategies which were less disruptive to society than a full lockdown worked.
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However even the severe lockdown strategy does not halt the spread of the virus; it just reduces it to a low level, which will spring back again when and if restrictions are lifted.
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==How does C19 compare with Spanish and ordinary flu?==
 
==How does C19 compare with Spanish and ordinary flu?==

Revision as of 13:33, 26 March 2020

SARS-CoV-2 genome: A=Purple T=Orange C=Yellow G=Red[1]

The physician and health researcher Hans Rosling regarded global pandemic as the greatest risk to human civilisation (followed by financial collapse, world war, climate change, and extreme poverty).[2] Could the coronavirus disease (COVID-19)[3] which emerged in Wuhan, China, in late 2019, and in early 2020 reached pandemic status, be the devastating pandemic Rosling feared?

The 1918 Spanish Flu killed up to 100 million people in a year (and the Black Death killed between a quarter and a half of the populations it affected)[4] but neither destroyed civilisation.[5]

Modelling work by researchers at Imperial College[6] suggest that, with no action by governments, the Coronavirus would kill around 2 million people in the US and half a million in the UK. With drastic measures to suppress spread of the virus the death toll could have been kept to below 20,000 in Britain (the researchers didn't publish figures for the USA).

What makes the big difference in numbers?

The flat red line is the capacity of the health system to cope with critical care patients

The Imperial College researchers modelled various scenarios for mitigating the spread of the disease, aiming to find a strategy which kept the numbers of people so badly affected that they need hospital treatment within the resources of the health system to treat them. Put bluntly, without hospital treatment, and especially without the availability of ventilators to assist breathing, most people who need treatment will die. With treatment about half will survive.

The model showed that none of the mitigation strategies which were less disruptive to society than a full lockdown worked.

However even the severe lockdown strategy does not halt the spread of the virus; it just reduces it to a low level, which will spring back again when and if restrictions are lifted.

How does C19 compare with Spanish and ordinary flu?

COVID-19 compared to Spanish and seasonal flu[7]

The best-case figure for UK COVID-19 deaths with vigorous mitigation measures is 20,000 people.[6] The population of the UK is about 66 million, so that is 0.03% of the population, or about one person in three thousand.

The figure of 510,000 in the UK without mitigation is 0.77%, or about one in every 130.[6]

For comparison the death rate from Spanish flu has been estimated at somewhere between 0.8% (one in 125) and 5.5% (one in 18).[8]

Ordinary seasonal flu claims about 0.05% (about one in twenty thousand).[8]

Thus the worst case for an unmitigated Coronavirus epidemic is similar to the lowest estimate of the death rate of the 1918 Spanish Flu.

However the Spanish flu pandemic was over a century ago, at a time when one in ten babies died before reaching their first year, even in the most prosperous country in the world.[9] Public health, and health expectations amongst the public, have changed radically in the intervening years, and the grim death toll of the earlier pandemic would today be regarded as horrific – and no doubt politically unacceptable, if it were known that an alternative were possible.

How does C19 compare with other causes of death?

COVID-19 compared to other causes of death[7]

Deaths from air pollution in the UK are 0.1% (about one in every thousand) per year.[10]

The UK has an average of 32,000 excess deaths each winter (0.05%, or one in two thousand) of which 9,700 (0.015%, one in seven thousand) were due to cold homes.[11] In the winter of 2017-2018 the number dying due to cold homes peaked at 17,000 (0.026%, one in four thousand).[12]

World-wide about 1.5 million people – mostly young children – still die of vaccine-preventable diseases. That's 0.02%, or one in five thousand.[13]

In the UK about 2000 people are killed on the roads each year: 0.003% (about one in forty thousand).[14]

An unmitigated COVID-19 epidemic would be a public health (and possibly political) disaster, but with mitigation the health effects could be brought down to levels comparable with other public health issues, some of which claim even more lives.

Suppressing the Coronavirus

Outcomes with the lowest death tolls depend on drastic measures to suppress spread of the virus:

  • social distancing of the entire population,
  • isolation of all cases,
  • quarantine of entire households where anyone is sick, and
  • closure of all schools and universities,

and for these measures to be maintained for 12 to 18 months, until a vaccine is available.[15] These measures will be hugely disruptive on many levels: physical, economic, social, and possibly political.

Social distancing

Compared to attempting to quarantine affected populations (or doing nothing) social distancing, where people reduce their contact with others, works best for slowing the spread of the virus. This article shows graphically how effective these approaches are.[16]

[17]

Footnotes and references

  1. The SARS-CoV-2 genome comprises 8 kilobytes of data, 29,903 base pairs of RNA. When this little string-shaped molecule gets inside a human cell, in its little delivery package, it codes for its own reproduction plus packaging for the new strings, and that is enough to bring the world to its knees. Graphic by /u/dx8xb. Data from Pubmed, GenBank MN908947.3 (From Facebook post by Zi Teng Wang)
  2. "Factfulness: Ten Reasons We're Wrong About the World – and Why Things Are Better Than You Think" by Hans Rosling, Ola Rosling, and Anna Rosling Rönnlund
  3. The virus which causes the COVID-19 disease is called severe acute respiratory syndrome coronavirus 2 (abbreviated as SARS-CoV-2)
  4. "In the Battle Against Coronavirus, Humanity Lacks Leadership" by Yuval Noah Harari in Time on 15 March 2020
  5. However the Black Death had profound effects on society: see e.g. "Social and Economic Effects of the Black Death" by Bright Hub Education, which observes that

    Before the plague, peasant serfs were confined to their lord’s estate and received little or no payment for their work . Overpopulation and shortage of resources led to malnutrition and extreme poverty for many peasants. After so many people died, serfs were free to move to other estates that provided better conditions and receive top pay for their work. Landowners, desperate for their labor, often provided free tools, housing, seed and farmland . The worker farmed all he could and paid only the rent.

    Serfs improved their standard of living too. Modern day archaeologists have found evidence that prior to the Black Death, most of the peasants relied on clay pots to cook their meals but in years following the plague pandemic, households used more expensive metal cookware.

  6. 6.0 6.1 6.2 "Impact of non-pharmaceutical interventions (NPIs) to reduce COVID19 mortality and healthcare demand" by Neil M Ferguson and others on behalf of the Imperial College COVID-19 Response Team; 16 March 2020
  7. 7.0 7.1 spreadsheet
  8. 8.0 8.1 "The Spanish flu (1918-20): The global impact of the largest influenza pandemic in history" by Max Roser in Our World In Data on 4 March 2020
  9. "The impact of the Great War on Infant Mortality in London" by Jay Winter, Jon Lawrence, and Jackie Ariouat in Annales de Démographie Historique Année, 1993
  10. "Cardiovascular disease burden from ambient air pollution in Europe reassessed using novel hazard ratio functions" by Jos Lelieveld, Klaus Klingmüller, Andrea Pozzer, Ulrich Pöschl, Mohammed Fnais, Andreas Daiber, and Thomas Münzel in European Heart Journal on 21 May 2019
    See also "Air pollution responsible for more deaths than smoking, study says" by Alex Matthews-King in The Independent on 12 Mar 2019
  11. "UK has sixth-highest rate of excess winter deaths in Europe" by E3G on 23 Feb 2018
  12. "17,000 people in the UK died last winter due to cold housing" by E3G on 15 Feb 2018
  13. "Global decline in vaccine-preventable diseases" by by Samantha Vanderslott, Bernadeta Dadonaite and Max Roser in Our World In Data on July 2015 (revised Dec 2019)
  14. "Reported road casualties in Great Britain: quarterly provisional estimates year ending June 2018" by Department of Transport on 8 Nov 2018
  15. "A chilling scientific paper helped upend U.S. and U.K. coronavirus strategies" by William Booth in The Washington Post (via msn.com) on 19th March 2020.
  16. "Why outbreaks like coronavirus spread exponentially and how to "flatten the curve"" by Harry Stevens in The Washington Post on 14 March 2020
  17. "We’re not going back to normal" by Gideon Lichfield in MIT Technology Review on 17 Mar 2020

    Social distancing is here to stay for much more than a few weeks. It will upend our way of life, in some ways forever.