The global case fatality rate, which fell consistently from May 1st 2020 until January 18th 2021, is now rising steadily and currently stands at 2.21%

The global Covid-19 case rate (those who have tested positive for sars-cov-2 by testing) has fallen recently, but the case fatality rate (those who have died of Covid-19 following a confirmed test) has not fallen in step with the case reduction.

The most obvious conclusion is that the Covid-19 fatality rate is just lagging the case rate by some weeks. Alternatively, the recent bad weather across much of Europe may have affected testing capacity.

There are other possible explanations though:

• More aggressive Sars-cov-2 variants are leading to an increase in the mortality rate without a corresponding increase in case rates – see here
• Sars-cov-2 variants may be evading testing?