Today we need to talk about ceiling effects

Numbers of COVID cases are rising globally
We know the true number is actually much higher due to many limitations including testing
Testing has improved but it still has limits
We may well see a plateau effect come into play

The number of people tested each day is limited by:

Test kit availability including swabs
Physical capacity to take tests including staff numbers
Lab capacity to run tests per day

Access to testing is often actively restricted by placing requirements on who is tested:

Limited to those who are in hospital
Limited to those with severe symptoms
Requiring a GP referral
Cost either for public or private testing

So numbers in a country, or region, may plateau, not because cases are plateauing but because test capacity has reached its limit

There are also limits on case reporting, as is there is with death reporting, which relies on all systems working appropriately

Systems are stretched and in some places inefficient

The other surrogate measure of hospital and ICU admission can also plateau:
Once places are full including overflow the count peaks out

But admissions rely on many factors:

Trusting the system enough to go to hospital
Having a hospital to go to
Having the means to get there

Mortality figures we have discussed briefly but they also rely on cases being determined to be COVID either by test or clinical suspicion
In an overloaded system individuals may never be tested or seen by medical staff so not recorded

Overwhelmed staff may not be available to make notifications
If people die at home and if there is not post mortem testing those deaths may never be recorded

We have already discussed reporting lags but in some cases the cases may never be reported at all

During the pandemic absolute numbers tell less than the whole picture