False claim : No worse than seasonal flu
Bruce produces a graph comparing COVID-19 to flu, purporting to show that it is not so bad. Well the first thing to note is that he gives projected deaths till August for COVID of 43749. But the ONS say that there were already 55,000 excess deaths due to the epidemic by the 8th of May – so the projection of 43000 for August is already wrong. He tries to make out that COVID is mild by using figures that had already been surpassed when he wrote.
But we can look at international comparisons to see what the death rate per 100,000 people normally is for flu and compare that with the COVID figures.
- We first have to compare the actual deaths so far with those expected per year from flu. We will show that covid is far worse.
- We then compare the infection fatality rate to see how bad it is for each person infected.
Data on the death rate flu
“Results: Annual estimates of influenza-associated deaths made using each model were similar and positively correlated, except for estimates from the summer-season rate-difference model, which were consistently higher. From the 1976/1977 through the 2002/2003 seasons the, the Poisson regression models estimated that an annual average of 25,470 [95% confidence interval (CI) 19,781-31,159] influenza-associated respiratory and circulatory deaths [9.9 deaths per 100,000 (95% CI 7.9-11.9)], while peri-season rate-difference models using a 15% threshold estimated an annual average of 22,454 (95% CI 16,189-28,719) deaths [8.6 deaths per 100,000 (95% CI 6.4-10.9)].” (https://pubmed.ncbi.nlm.nih.gov/19453440/)
Using Worldometer data we can compare this with flu
|Country||Death rate per 100,000||How much worse than flu|
|Long run average per full year for Flu USA||9.9||1|
|March to 22 May 2020 Covid 19 USA||28.2||2.8|
|March to 22 May 2020 Covid 19 Sweden||38.3||3.9|
|March to 22 May 2020 Covid 19 UK||52.5||5.1|
It is clear that it is already much worse than flu. It has so far infected only a small portion of the susceptible population, The latest UK serology data indicates that it has infected 6.5% of the UK population, far fewer than get infected by flu. So the risk, if the virus spreads is that deaths could rise by a factor of around 10. Were this to be allowed to happen the impact would be of the order 50 times worse than flu.
The case fatality rate for flu, deaths as a percentage of people diagnosed with symptoms is of the order of 0.1%, but many people get mild flu and are not diagnosed, so this is an upper bound. The case fatality rate for those diagnosed with COVID in the USA is 6%, 60 times worse.
Even the infection fatality rates for COVID, that is to say the rate you get by including all those who test antibody positive but my never have shown symptoms is much worse than the upper bound for flu.
Using the latest UK serology survey, we see that the rate for the country as whole is of the order of 1.3%. So the infection fatality rate for COVID is 13 times the case fatality rate for flu.
|reported share infected||17.00%||6.55%||5.00%|
|ifr using excess deaths||1.33%|
Note that flu deaths are also computed using the ‘excess mortality’ method. Note also that London has a lower death rate than the rest of the UK. Risks from the disease vary with wealth, age and ethnic background. London is richer and younger than the rest of the country which may account for the lower death rate there.
So Bruce’s attempt to show that the disease is no worse than flu is massively misleading.
A Confusion over R
Bruce writes, speaking of Ferguson’s predictions of death rates.
‘ He projected it as being as high as 500,000. As there has been no large-scale community testing the actual infection rate, or “R rate”, isn’t known and can only be estimated on the basis of limited data. It is more likely much lower than 80 percent and probably nearer 17 percent.’
This shows a whole series of misunderstandings.
- The R rate does not refer to the percentage of people infected. R refers to the Reproduction rate of the virus. That is to say how many other people get infected by an average infected person. The estimate of between 2.5 and 3 is based on detailed contact tracing information from China.
- What Bruce is wanting to say is that the infection rate, the percentage of people infected is unknown.
- This is not true now. The ONS infection pilot survey released May 14 said :At any given time between 27 April and 10 May 2020, it is estimated that an average of 0.27% of the community population had COVID-19 (95% confidence interval: 0.17% to 0.41%).
- What matters in estimating total expected deaths from the epidemic is neither the R rate nor the current infection rate, but the proportion of the population who are likely to eventually get the disease. Given that this is a disease to which the population has never been exposed, an 80% estimate of how many would catch it the absence of public health measures is for the mathematical reasons I explained in my original posting. We expect the portion eventually infected to be >(1-1/R). Bruce gives not math to justify his estimate of 17% – which is not surprising as he clearly does not understand what R is.
Inter country comparisons
Bruce attempts to argue against lockdown in the UK by saying that some countries have much lower death rates than us despite not having a lockdown.
The spread of the disease to a country depends on many factors:
- How much international travel it has
- Highly connected countries have more infected people travel to them
- Inherent susceptibility of the population
- This may vary with race
- This may vary with age structure
- This may vary with
- Flu spreads most in cold dry conditions, high heat and humidity slow spread
- If COVID 19 spreads similarly, then it will also be affected by climate
- The speed with which the government reacts
- Rapid closing of borders
- Good testing and tracing
- Good isolation of all infectees and contacts
Of course if a government were to believe the nonsense that Bruce is now advocating – that it is no worse than the flu then they would be complacent and do nothing until too late. Sounds like Boris and Nicola.
Then suddenly it would dawn on them that this is not just the flu, so they shifted to a fall back position : ‘take it on the chin’, ‘you will lose your loved ones’.
That is the position that Bruce is stuck in with his advocacy of herd immunity and the Swedish approach. An approach that has now led to the worst death rate in the world.
At least the UK governments snapped out of that delusion.
UK would not have needed a lockdown if the Tories and the SNP had taken sensible steps in February. If they had closed the borders and had vigorous tracing and quarantining of all contacts with known case, then we would not have needed a lockdown either.
But we have to deal with the mess that Boris and Nicola have got us into. They allowed rampant uncontrolled spread of the virus and dithered for weeks. That left lockdown the only option and meant that lockdown has had to last longer than it would otherwise have done. The ruling class in Scotland and England have made a terrible mess of things. They have tens of thousands of deaths to their account.
At the moment, the employers are pressing workers to return to work as soon as possible. Unions are resisting being forced to return to work under unsafe conditions.
Now is not the time for people associated with the left to repeat misleading critiques of lockdown that originate with the right and the employers.