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A Birder’s Guide to Novel Corona Virus COVID-19 from Our World In Data

March 17, 2020

We here at SMBAS Blogsite Central are utterly certain that you simply aren’t getting enough information on all things COVID-19, so we voted democratically and decided to assign extra staff in order to help keep you informed on what you need to know.

Actually, the blog title is somewhat misleading. It doesn’t matter whether you’re a birder or not.

0.3 Microns. So small you can’t see it.

This blog contains nothing that you can’t find by going to this site:

The information there come directly from the World Health Organization (WHO) and is updated daily. A few of their many interesting charts – some interactive – are shown below. Explanations and commentary are adapted – mostly shortened – from their website. We apologize for any blurriness of charts, the result of “snipping” screenshots. They are clear on the website

Our World In Data has a great deal of information on many topics other than Corona virus, including: carbon footprints, 1918 Spanish Flu, population, safe sources of energy, cancer, less meat vs. “sustainable” meat. This is a site well worth your while.
[Chuck Almdale]

Growth: Country by country view
How long did it take for the number of confirmed deaths to double?
The table below also shows how the total number of confirmed deaths, and the number of daily new confirmed deaths has changed over the last 14 days. China seems to be dropping. On-line you can sort the table by any of the columns by clicking on the column header.

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Current COVID-19 test coverage estimates

These are the most recent official estimates of tests we have been able to find as of 13 March 2020, 09.00 GMT. Note that the estimates refer to different dates for each country, as indicated in the brackets.

The chart below shows the number of tests relative to the size of the population: it is the number of total COVID-19 tests per million people. Available data shows that South Korea has done many more tests than any other country. This suggests that the number of confirmed cases in Korea is closer to the total number of cases than in other countries. It is therefore particularly encouraging to see that the number of daily confirmed cases in South Korea has decreased – here you find our chart that shows the decline of confirmed new cases in South Korea. The fact that South Korea has managed to expand testing so quickly shows that it is possible. Because testing is crucial it is important that in the coming days other countries follow.

The US, on the other hand, has experienced big problems rolling out their testing strategy and according to the US Centers for Disease Control and Prevention, only a total number of 13,624 samples had been tested by 12 March, 2020. The total number of tests conducted in South Korea up to the same date was nearly 18-times larger. The low test coverage of the US is even starker if we look relative to the large population of the country. We see many smaller countries have been able to conduct more tests per million people.

[NB. Two estimates provided for the US. The estimate labelled “US – CDC samples tested” is from the Centers for Disease Control and Prevention, and refers to the number of tests conducted, not the number of individuals tested. The COVID Tracking Project tracks the cumulative number of people tested in the US by tallying individual state reporting. We report these figures under the label “US – COVID Tracking Project”]

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Early data from China suggests that the elderly are most at risk
Understanding who within a population is most at risk is crucial in an outbreak. Understanding the relative risk to different sections of a population allows us to focus on the most vulnerable, and improve the allocation of health resources to those who need them most.

The Chinese Center for Disease Control and Prevention has published an analysis of recorded cases and deaths in China for the period until February 11th 2020 which provides a breakdown of all known cases, deaths and the CFR by specific demographics (age, sex, preexisting condition etc.).

A breakdown of the CFR by age group is shown in the visualization below. It shows very large differences of the CFR by age.

For many infectious diseases young children are most at risk. We see this for malaria: the majority of malarial deaths (57% globally) are in children under five years of age. The same was true for the largest pandemic in recorded history: During the ‘Spanish flu’ in 1918 it was primarily children and young adults who died from the pandemic (we write more about this in the article here).

For the COVID-19 cases in China the opposite seems to be true, at least based on the information available at the time of writing. The elderly are at the greatest risk of dying if infected with this virus. Based on the data from China – shown in the visualization – 14.8% of those who are 80 years and older who were infected by COVID-19 died as a result. As explained above, these figures represent the share of people diagnosed as having the disease who die from it. This does not represent the share of people in the entire population who die from it.

The case fatality rate for children is much lower. There were no reported deaths in children under 10 years old; 0.2% of those aged 10 to 19 years who were diagnosed with COVID-19 died from it according to the early Chinese data.

One possible reason why the elderly might be most at risk is that they are also those who are most likely to have underlying health conditions such as cardiovascular diseases, respiratory diseases or diabetes.

The symptoms of COVID-19
The WHO described the symptoms of 55,924 laboratory confirmed cases of COVID-19 in China in the period up to February 20. The visualization below shows this data.
It is most crucial to know the common symptoms: fever and a dry cough. As the visualization shows, close to 90% of cases had a fever and two-thirds had a dry cough. The third most common symptom was fatigue. Almost 40% of cases suffered from it. ‘Sputum production’ was experienced by every third person. Sputum is not saliva. It is a thick mucus which is coughed up from the lungs (see here).

Of the 55,924 cases fewer than 1-in-5 (18.6%) experienced shortness of breath (‘dyspnoea’). An earlier study, reported that a much higher share (55%) of cases suffered from dyspnoea, but this was based on a much smaller number of cases (835 patients). Many of the most common symptoms are shared with those of the common flu or cold. So it is also good to know which common symptoms of the common flu or the common cold are not symptoms of COVID-19. COVID-19 infection seems to rarely cause a runny nose.

‘Flattening the curve’
Early counter-measures are important in an epidemic. Their intention is to lower the rate of infection so that the epidemic is spread out over time such that the peak demand on the healthcare system is lower.

Containment measures are intended to avoid an outbreak trajectory in which a large number of people get sick at the same time. This is what the visualization shows.

This is the reason that limiting the magnitude of peak incidence of an outbreak is important. Health systems can care for more patients across an outbreak when the number of cases is spread out over a long period rather than condensed in a very short period.

What such counter measures to the pandemic attempt to avoid is that the number of patients at one point in time is so large that health systems fail to provide the required care for some patients

Early data from China suggests that those with underlying health conditions are at a higher risk
The visualization below shows the case fatality rate for populations within China based on their health status or underlying health condition.

The researchers found that the case fatality rate (CFR) for those with an underlying health condition is much higher than for those without. More than 10% of those diagnosed with COVID-19 who already had a cardiovascular disease, died as a result of the virus. Diabetes, chronic respiratory diseases, hypertension, and cancer were all risk factors as well, as we see in the chart.

The CFR was 0.9% for those without a preexisting health condition.

Three charts above we saw that the elderly are most at risk of dying from COVID-19. This might be partly explained by the fact that they are also most likely to have underlying health conditions such as cardiovascular disease, respiratory disease and diabetes; these health conditions make it more difficult to recover from the COVID-19 infection.

How do case fatality rates (CFR) from COVID-19 compare to those of the seasonal flu?
Comparing the CFR during the outbreak of COVID-19 in China with the CFR of the US seasonal flu in 2018-19.

The case fatality rate of the seasonal flu in the US is around 0.1% to 0.2%, while the case fatality rate for COVID-19, measured in the cited study, was 2.3%.

As calculated above, the global CFR for COVID-19 continues to change over time, and the global average CFR based on the WHO data is 3.4% (as of 9th March 2020). While the CFR for COVID-19 is much higher than the CFR of the seasonal flu the two diseases are similar in the profile of the fatality rate by age: elderly populations have higher case fatality rates. However, the CFR of COVID-19 is much higher for all age groups, including young people. On top of each bar we have indicated how much higher the CFR for COVID-19 is for each age group.

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