serious. If the 3.4 per cent figure is correct that is far more deadly than flu for example, which kills less than
1 per cent of those infected.
But calculating mortality rates require full information on the numbers infected and it is almost certain at
this early stage that we don’t know the full picture. The WHO accepts there is still a lot that is unknown
about the Covid-19 virus.
Experts were quick to point out that while you can say how many people have died, the point at which they
die and the total number of infected is difficult to really know.
Coronavirus has a long incubation so many people may have the disease but not be counted in the figures. If
they were, the mortality rate would be lower as the numbers infected but not dead would grow.
This is a likely position given some countries such as the US and Iran have had only limited testing and the
fact that the vast majority will only experience mild symptoms. It is only a small minority that have actually
had more severe issues
Prof John Edmunds, from the Centre for the Mathematical Modelling of Infectious Diseases, at the London
School of Hygiene & Tropical Medicine, said it well: “What you can safely say is that if you divide the
number of reported deaths by the number of reported cases you will almost certainly get the wrong
answer.”
Dr Jennifer Cole from the University of London added that it was likely the fatality rates would fall with
time as more people are diagnosed and tested.
It is also difficult to know how comparable the early cases in China are comparable to those in western
countries where hospitals may be able to provide better care.
Most experts agree the true mortality rate may not be known for some time but is likely to be lower than 3.
per cent with between 1 and 2 per cent being a reasonable view.
This is still a serious infection and such a mortality rate, if widespread throughout the population, would
mean significant strain on the NHS.
This is why the government is taking it so seriously.