Covid19 New Cases Up but Fatality Rate Down – Is this a positive sign?

On 11 October 2020 in the UK the number of new cases hit an all-time high of 12,872 per day; on the same day the number of deaths was recorded at 65. However if you go back to April 2020, we were getting over 5,000 new cases a day and over 1,000 deaths per day.  So in April 2020 the death rate was 1 per every 5 new cases but on 11 October 2020 the death rate was around 1 per every 200 new cases which seemingly shows that the virus is 40 times less lethal than before.

Graph showing the number of new cases in the UK since the start of the year:-

Source by Wikipedia

Graph showing the number of deaths per day since the outbreak in the UK:-

One can argue that after somebody contracts the virus it might take them a couple of weeks to die so we are not taking into account the lag for the virus to cause death. According to the Telegraph if you were going to die from Covid-19 it would take on average 18-days for the virus to knock you off after contracting it ( – so the death rate in 18 days time (which is 29 October 2020 [11 October + 18 days]) will be very important. If the virus is still as lethal as it was April 2020 then on 29 October we should get around 2,400 deaths.

However we can extrapolate that based on the death rate of 65 on 11 October, 2020 it means that on ~23 September 2020 [11 October 2020 – 18 days] there should have been around 65 * 5 = 325 new cases if the virus was killing 1 in every 5 infected but actually the number of new cases was 6,208 on the 23 September 2020. So assuming that the virus took 18 days on average to kill you the death rate of Covid-19 is now at 325 / 6,208 – which is around 1 in 200 – this is significantly lower compared with 1 in 5 in April 2020.

Statistics from Other Countries

In Singapore, so far 28 deaths have been recorded and the total number of cases to date stands at 57,904 – this puts the death rate at 1 in ~2,500 which is 2.5 less than what the flu kills normally which was around 1 in 1,000 in 2019.


So assuming that going from  a fatality rate of 1 in 5 in April 2020 to 1 in 200 in October is too large to be caused by standard deviation or measurement error I have outlined a number of potential reasons for the drop in fatality rate:-

  • Medical Professionals are better at treating patients
  • Virus has mutated to become less lethal
  • The methodology for measuring death from Covid-19 has changed
  • The testing of the virus is picking up on other strains of Coronavirus and/or other viruses

Let us examine each of the possibilities.

(1) Medical Professionals are better at treating patients – This is certainly very possible as medical staff have more experience with different drugs and treatments; for instance putting patients on a ventilator was almost a death sentence in itself and this practice has almost stopped entirely. What most people don’t tell you about is that patients have to put under general anaesthetic before they can use the ventilator and the process of sticking a tube down one’s bronchial is extremely invasive and under general medical practice intubation should not last for more than 7 days due to the risk of infection from prolonged use.

(2) Virus has mutated to become less lethal – This is also very possible; given that Covid-19 is an RNA virus which has a much higher rate of mutation compared to DNA viruses from nucleotide substitution from replication. The much reduced lethality also points to the potential of unnatural origins (that the virus was man-made) because anything that is unnatural will often will mutated out quickly through natural selection.

(3) The methodology for measuring death from Covid-19 has changed – This is unlikely to have changed much since April 2020; even if it has changed slightly it would not precipitate this magnitude of change in the death rate.

(4) This is also possible in combination with the mutation of the virus; as Polymerase Chain Reaction (PCR) is the main mechanism for detecting the virus but PCR uses carefully designed primers to amplify the genetic material and these primers are not always accurate; so the Covid-19 test has shown some positive results for SARS-Cov (the SARS of 2002). Even if the virus mutated slightly the Covid-19 test will still likely give positive results and it will not be able to detect potential changes in the  genomic sequence of the original testing assay.