The Star (25 May 2021) gives the following statistics regarding the Covid epidemic:
- Total cases: 518,600
- Total deaths: 2,309
- New cases (24 May): 6,509
- Deaths (24 May): 61
Based on the above figures, we can calculate that the overall case fatality rate (CFR) for Malaysia is 0.44% (2,309/518,600). If we calculate the CFR for 24 May using the new cases on 24 May as denominator (61/6,509) we get a figure of 0.94% – more than double the overall CFR.
But we know that most deaths do not occur on the day of diagnosis. Deaths tend to occur about 10-14 days after the onset of symptoms, because of tissue damage and clot formation caused by over-reaction of the patient’s immune system.
So, using 6,509 as denominator isn’t quite correct.
If we wish to get a better estimate of the CFR, it would be more accurate to use the average number of new cases 11 to 14 days earlier as the denominator. New cases on 11-14 May were 4,113, 4,855, 4,765 and 3,973, giving an average daily rate of new cases diagnosed of 4,434. The CFR based on 61 deaths with 4,434 as denominator is 1.38% or three times the overall CFR of 0.44%.
There are some who question whether this increase in case fatality CFR is artefactual (inaccurate due to a systemic error) because of the way we are identifying cases. They point out that if the increase in the number of cases has overwhelmed the capacity of the health services to trace contacts and test them, then a larger number of asymptomatic cases will not be identified. This would diminish the denominator and thus push up the CFR.
But it is unlikely that the increase in the CFR is entirely due to “artefactual” causes. My hunch is that the most important cause of the elevated CFR is the variant now spreading through our population is causing over-reaction of the immune system in a larger percentage of the people infected compared to the earlier strains.
One other possible cause of the observed increase in our CFR could be inadequacy of medical care. Currently, about 25% of the patients diagnosed with Covid go into stage four in terms of severity, and they require supplementary oxygen and high quality care by an experienced team.
If the sheer volume of such cases overwhelms the medical services, then some of them might die because they did not receive the medical intervention they needed – oxygen, steroids, anticoagulants and a lot of other things.
This appears to be the case in India at present, but we probably have not reached that stage in Malaysia just yet, though our acute beds for Covid in urban centres are almost completely filled. We are currently at about 80% occupancy of the 850 critical care beds allocated for Covid cases in the public sector. If we do not reduce our incidence rates quickly, we might exceed intensive care unit (ICU) capacity, and our CFR will go up even more!
What all this means is that we are dealing with a more dangerous variant of Covid now, and are dangerously close to overwhelming the capacity of our healthcare system to provide high quality care to all those who deteriorate to stage four or five.
This underlines the importance of staying in, reducing trips out to a minimum and strict adherence to the Covid-prevention rules when we do go out.
We need to work together to disrupt Covid transmission. We also need to combat vaccine hesitancy, counter the paranoia spread by anti-vaxxers and encourage our family members and friends to sign up for the vaccine so that we can build herd immunity and escape from this cycle of lockdown, partial relaxation and lockdown again.