Sunday, 15 March 2020

COVID-19 Confirmed Cases 14 March 2020

Currently we have the following COVID-19 case growth in Australia:
Date COVID-19 Cases in Australia Reference Assume 18% daily exponential growth
1/03/2020 25 1 25
2/03/2020 29 2 30
3/03/2020 30 3 35
4/03/2020 39 4 41
5/03/2020 52 5 48
6/03/2020 57 6 57
7/03/2020 65 7 67
8/03/2020 63 8 80
9/03/2020 80 9 94
10/03/2020 91 10 111
11/03/2020 116 11 131
12/03/2020 156 12 154
13/03/2020 156 13 182
14/03/2020 197 14 215
15/03/2020 283 15 254

The WHO estimate the COVID-19 has reproduction value (called R0) of 2.5, that is an infected person will spread virus to 2.5 other people on average without containment:

 If we can reduce number of contacts by 90% with containment then the virus has 90% less opportunity to spread. 

 Today (15/3/2020) we have 283 COVID-19 cases in Australia and if we have 18%+ exponential daily growth. If we extrapolate 18% daily exponential growth we will have:
  • 31/3/2020: 3,584 cases 
  • 30/4/2020: 850,820 cases
If we compare Australia to other countries we can see Australia is roughly 18 days behind Italy:
If COVID-19 cases grow at current exponential rate as they have done in other countries our healthcare system is likely to be overwhelmed as we do not have required capacity to handle a pandemic. Potential issues:
https://www.abc.net.au/news/2020-03-15/italy-coronavirus-warning-about-impact-of-covid-19/12052578
  • Lack of hospital beds
  • Lack of Intensive care beds
  • Lack of specialist doctors, nurses and other healthcare works as many patients require one on one attention
  • Lack of ventilators for patients needing treatment for pneumonia
  • Lack of resources
If we continue with current 18% exponential growth rates and assuming we have free capacity of 1,000 ICU beds, then we will run out of ICU bed capacity on 9/4/2020:

 To avoid the crisis Australia should attempt to flatten the curve of COVID-19 cases:

The most effective way to stop spread of infection is to minimise contact by closing down schools, public transport, mass gatherings and to encourage people to work from home:
We can slow the rate of transmission so it takes longer for people to come into contact with someone who is infected. In the absence of these measures we would see the number of infected people rising very quickly. Yet if we can dampen transmission of infections and prevent it, we would slow down the progress of the infection.

 Hospitals will be better able to care both for patients infected with COVID-19 and those with other urgent health needs. Measures to slow the outbreak can also buy time for scientists to develop better diagnostics, therapies, and eventually a vaccine.

The UK strategy for dealing with COVID-19 is 'herd immunity', see details below:
https://www.theguardian.com/world/2020/mar/13/herd-immunity-will-the-uks-coronavirus-strategy-work
https://en.wikipedia.org/wiki/Herd_immunity  
Herd immunity is the resistance to a contagious disease within a population because enough people (60%+) have become immune, and so it is harder for it to spread.  Based on this idea the government wants people to get infected with COVID-19 up until hospitals reach capacity and only then go into lockdown. Yet this strategy is very risky as community transmissions will continue and potentially overwhelm the healthcare system causing many people will unnecessarily die.  There is is significant risk that herd immunity strategy may not be able to control and balance the number of cases! 

Here is some rough math for UK:
  • Herd immunity level 60% = 39,864,000 cases
  • Critical cases needing intensive care 5% = 1,993,200 
  • Assume spare intensive care beds: 1,000 ?
  • Assume typical duration of ICU for COVID-19: 2 weeks
  • Then time required to get through COVID-19 patients with current resources without kicking out normal ICU patients: 76 years. Meaning death sentence for patients as system is overwhelmed!
Dr Tedros Adhanom Ghebreyesus, the WHO director general said: “The idea that countries should shift from containment to mitigation is wrong and dangerous.”.

Seems like the UK plan to let the ordinary people to get infected and potentially die in overwhelmed public hospitals. This seems like a strategy to prioritise the economy over health of a nation:

Now Australia is following the UK strategy, our politicians do not want to close schools and our chief medical officer, Brendan Murphy suggested children getting infected may contribute to herd immunity....meaning our government encourage herd immunity and want people to get infected. Even though children may not develop severe symptoms from COVID-19 children that attend school are likely to pass the virus to their parents, siblings, friends and relatives; thereby ensuring infections will continue to spread exponentially, this strategy does not help to flatten the curve of COVID-19 cases.

 The majority of medical professionals support lockdown to delay infections:
https://www.smh.com.au/national/should-we-be-locked-down-experts-split-on-hardline-covid-19-measures-20200315-p54a8y.html
Experts supporting lockdown Experts against lockdown
Business for Doctors "almost unanimous" opinion of their 27,500 members.
Founder, April Armstrong, a Western Australian GP, said "Doctors are putting family in isolation now. We are taking our children out of school now. We're telling all our family and friends to stay at home and the reason we're telling them to stay at home is that trajectory [of COVID-19 cases] is going to be really steep."		 Dr Trent Yarwood, an infectious diseases physician based at the University of Queensland said "At this stage, pausing the economy does not make sense given it is not clear if there is sustained community transmission"
Medical Journal of Australia editor-in-chief Nick Talley called for the government to impose stricter social-distancing measures to slow the spread of the virus. "It is very hard to see the curve flattening out with what we’re doing. It’s community transmission and it’s fairly widespread," Professor Talley said. Associate Professor Julian Rait, president of the Australian Medical Association’s Victorian chaptesaid "Campaigns calling for people to lock themselves down, like the widely circulating online "Stay The F--k At Home" push, were "probably a bit drastic". "There may well be a time for that," Professor Rait said. "But this is a staged approach – we agree with the Chief Medical Officer at this stage about the advice.
Dan Suan, a staff immunologist at Westmead Hospital in Sydney's inner west, also warned his Facebook followers that Australia had only a narrow window of opportunity to flatten the curve of new infections, recommending total social isolation, complete interpersonal distancing and massively increased testing.
Australian Medical Association WA president Andrew Miller said research from China showed intervening in community gatherings and closing schools had an “amazing effect” in reducing coronavirus infections – a week's delay in bringing in closures could see an increase of up to three times the amount of cases.

Italy still has exponential daily growth rate of new cases  and now is registering one death due to COVID-19 every 4 minutes. Australia had 27,000 casualties during World War II, assuming COVID-19 pandemic mortality rate is 1.5% and will infect 60% of the Australian population before we get herd immunity then we could unfortunately see 15,000,000 infections x 1.5% mortality = 225,000 deaths. Implication is that COVID-19 can potentially have significantly more deaths than World War II. We should not panic, but we must clearly be prepared to tackle this emergency and take action to flatten the curve and save many lives.

The most fundamental function of a government is to keep its people safe. It is from this that it derives its authority, the confidence of the people and its legitimacy. Nobody should be under the illusion that somehow we can allow COVID-19 exponential growth and still expect our healthcare to operate. The government needs to close the schools and do whatever it takes to flatten the curve.

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