How deadly is CORONA (COVID-19) really? (in The Netherlands)

24th of March 2020 (update 26th of March) By Jacqui van Kemenade, GP Netherlands

Are we looking at a case fatality rate of 0.4%, 4.5% or 8.3%? Things seem to get even more confusing after well known UK epidemiologists like Neil Ferguson and Sunetra Gupta seem to have conflicting prediction models. Neil Ferguson created the highly-cited Imperial College London coronavirus model, which has been instrumental in governmental policy decision-making in the UK, Ferguson revised his model this week predicting that instead of the estimated 500,000 people dying from COVID-19 in the UK, with good measurements it will be 20,000 or even fewer. What does this mean for other countries like The Netherlands and what makes it difficult to predict the fatality rate? Is it just adequate measurements that will decrease the rate or is the fatality rate easily over-amplified?

This article takes a close look at the COVID-19 fatality rate and current medical risk factors

Since 2 weeks we (17 million Dutch people living in a country which counts 41,543 sq km, which by the way is 3 times smaller than the size of New York State) are all sitting anxiously at home. Most of us keep an appropriate 1.5 meters away from potential contaminated others while doing our groceries. Even our non-compliant teenagers who were found partying in the park, have now been persuaded by our determined Prime Minister to practice social distancing. Which is a huge challenge at that age. Schools and Universities are closed. All social events have been cancelled. Everybody who is able to work at home is urged to do so. We don't want to get infected, but even more than that; we don't want to get sick. Because some people who do get sick actually die.

But how deadly is the COVID19 virus really? It seems to depend on the country you live in. Of course, this is not due to any distinct geological characteristics of a specific country, but above all, it seems to depend on the manner of testing and counting, which is hugely different per country. Fatality prediction seems to change by the day.

It is custom to use the Case Fatality Rate index (CFR), to indicate the lethality of a virus. That is the total number of deaths divided by the number of confirmed infections, times 100. During a normal flu season, the CFR is 0.1 percent. For example, today, Tuesday March 24th, there are 22,762 people who have been tested positive in our neighbouring country Germany. Of these, 86 have sadly passed away. The fatality rate is thus 0.4 percent. In Italy, however, this is much higher: 8.3 percent. That means that out of 100 sick people, more than 8 people will die. In Britain, this figure is 2.2 percent.

In the Netherlands, there are 4749 people who have been tested positive. A total of 213 people have died due to a pneumonia or illness induced by this virus. This means that our fatality rate is quite high: 4.5 percent. All in all, one could conclude that is is better to live in Germany than in Italy.

 Ofcourse there is a big ‘But’. These figures give a very distorted view. In Germany, there is a very active testing policy, and the threshold to test is very low. Tests are available to anyone with minimal symptoms. Mass testing has also taken place in South Korea giving a CFR of 0.6%.

In The Netherlands we do minimal COVID-19 testing in the home setting. Even if one has mild symptoms consistent with Corona, the protocol is to stay home and assume that one is contagious. People are therefore kept in ignorance and can only guess whether there has been an infection or not. This is stressful and uncertain and can be difficult to cope with. But considering the fact that 80% of people have mild symptoms and will not develop serious symptoms this is understandable. Also testing itself forms a risk for the health professional who has to do the testing. These are all difficult considerations and decisions to make.

Testing is only done if a pati?nt has to be admitted to hospital. Due to the restraints in testing we probably have a fatality rate which in reality will be much lower. In The Netherlands a total of 213 have died due to a COVID-19 infection. This gives us a 4.5 percent fatality rate. But if we had tested everybody with mild symptoms then we probably would have had closer to 20.000 than 5000 positive people. This would give a substantial decrease in the CFR. So we have to face the fact that we just don’t know how many people truly are infected and we just don't know the true fatality rate.

Oxford epidemiologist Sunetra Gupta has been critical of the current predicted fatality rate. Gupta led a team of researchers at Oxford in a modeling study which suggests that the virus has been invisibly spreading for at least a month earlier than suspected, concluding that there is a much bigger chance that as many as half of the people in the United Kingdom have already been infected by COVID-19. A true fatality rate can only be calculated if one is absolutely certain of the number of people who have already been infected.

My guess would be that Germany is showing a number which is close to the truth. However the low CFR in Germany is not only due to mass testing but will also depend on the capacity of the intensive care units. If the peak flow of new patients is too high and exceeding the capacity of the intensive care units, then patients will not be able to get proper care and this will also demonstrate an increase in CFR. One can only assume that this has probably been the case in Italy. 

After infection, who is at risk of becoming really ill or even dying?

 This depends on:

- Age: The age of the deceased in The Netherlands is between 55 and 97 years. (The average age at death is 82 years) If You are under 55 years old then your risk is a lot lower. -

-Gender: Are you male or female? Good to know for sure because men seem to have a higher risk; Of the people who have died so far in our little country 62.5% were men.

- Underlying condition?

 Which specific medical conditions did our deceased with COVID-19 have? 

 The Top 5 medical conditions found in the 213 deceased patients were:

27.5% : cardiovascular disease and /or high blood pressure 

15.9% : diabetes 

12.7% : chronic lung disease

6.9% : chronic kidney disease

6,3% : malignancy

 Ofcourse we can also identify specific pati?nt groups who will be more vulnerable 

Vulnerable persons or people are people who are more at risk of becoming severely ill after a COVID19 infection. These are people aged 70 years and older and people who have any of these conditions:

· Abnormalities and functional disorders of the airways and lungs

· Chronic heart disease

· Diabetes mellitus type 1 of 2 

· Severe kidney disease leading to dialysis or kidney transplantation

· Reduced resistance to infections

· Medication for autoimmune diseases

· status after organ transplantation

· hematologic disorders (blood disorders)

· congenital immune disorders or treatment with chemotherapy and /or radiation (in cancer patients)

· HIV human immunodeficiency virus infection  

In this list I still miss people who are (severely) overweight. This groep is also vulnerable in that they have a deficient immune response and treatment in an intensive care setting can be more challenging. 

In summary: Fatality rate has probably been overrated due to spread of the virus way before people were being tested and because of minimal testing in countries like The Netherland. The total amount of people who have already been infected will thus be, and has been, underestimated. Overall, it is reasonable to assume that our fatality rate in the Netherlands is probably below the estimated 4.5%. We test much less frequent compared to our neighbour Germany. Vulnerable people with additional medical conditions have more chance of developing serious symptoms after infection bij COVID-19. It is up to the non-vulnerable people to realise, even without being tested, that one can be contagious. It is thus of utter importance to take the social distancing measures seriously. Not just to protect yourself, but to protect that other person in your neighbourhood, who will get sick because of your possible irresponsible behaviour. So let's listen to our own Prime Minister who urged us once again during prime-time TV this week; keep your distance, don't visit your gran, and realise that even if you are not ill, you can be a possible source of infection and danger to others. Also we need our health professionals on the I.C units to be able keep doing their job in a responsible way, which by the way they are! This can only be done if the flow of patients does not exceed the capacity. Let's help our health professionals and keep our distance.

Jacqui van Kemenade, GP The Netherlands