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Monday, 17 August 2020

 Global COVID-19 Containment: Confirmed Cases, Updated Daily


Global COVID Containment: Confirmed Cases, Updated Daily

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Sometimes, it helps to gain a fresh perspective.

Since the pandemic began, there have been innumerable tracking resources made available online, but rarely do they paint a complete picture of a country’s containment progress.

How Much Progress Is Really Being Made

Featured above, this continuously updated chart from Our World in Data provides a more complete look at the efficacy of COVID-19 containment strategies, sorted by country.

It is a variation of the Epidemic Curve (or “epi curve”), showing confirmed COVID-19 cases per country in relation to their testing rates—what’s revealed is the strength of each country’s containment strategy.

Only a fraction of total cases–those confirmed by a test–is known. This is why we spent recent months building the database and the visualization tool to make this variation of the epidemic curve possible.

— Our World in Data

Why Look at it This Way? Adequate Benchmarking

Countries vary widely in how they monitor and report on COVID-19. Cases in this particular chart were confirmed via laboratory testing, and the data covers 66% of the globe’s population.

Depending on a country’s containment efforts, confirmed cases can differ dramatically from total cases. To get a better idea of that difference, Our World in Data looked closer at the extent of testing. As they report, the World Health Organization considers an adequate benchmark to be 10-30 tests per confirmed case. And for those countries that experience larger outbreaks, there must be more tests conducted per confirmed case.

What the COVID Test-to-Case Ratio Tells Us

  • Line Trajectory: In this chart, rising lines show that the average number of laboratory-confirmed cases has increased over time, and vice versa for falling lines. Beyond flattening the curve, the end game is to have all of those lines reach zero.
  • Blue Lines: The darker the blue line, the more likely that the line is an accurate indicator, as thousands of tests have been administered per confirmed case. The more blue lines this chart shows over time, the better for us all.
  • Red Lines: By contrast, the warmer the color of the line, the fewer tests are being administered per confirmed case, and it is less likely to be an accurate measure of COVID-19 cases. Red lines, for example, indicate that only five tests are conducted for every confirmed case, suggesting that the count is not accurate and that many cases are going unreported.
Epi Curve Scenario Examples

Consider these three scenarios in the diagram above, and hover over countries in the main visualization to compare:

  • Country A: Winning the fight against COVID-19.
    These countries, like New Zealand, have steadily increased the number of tests per confirmed case. Country A administers hundreds or thousands of tests per confirmed case. The likelihood of missed cases is far lower, most cases are accounted for, and they can confidently state they are winning the fight against COVID-19.
  • Country B: A severe, prolonged outbreak.
    In comparison, countries like the U.S. have experienced a steady rise in confirmed cases. They also have lower rates of testing—only five tests per confirmed case. Country B cases are likely to be higher than the number reported, a fact that is especially concerning given that the U.S. has already surpassed the rest of the world’s countries in confirmed cases.
  • Country C: A volatile scenario.
    While confirmed cases decrease, there is much room for doubt. In Country C (South Africa for instance), confirmed cases are decreasing, but very few tests are administered. Unfortunately, this indicates there are many unrepresented cases. Country C probably has a larger problem than its downward trajectory would indicate.

Cases Per Million People

From a different angle, we can see daily new COVID-19 cases per capita. This gives us a better sense of how countries compare in terms of confirmed cases.

Countries like Thailand, New Zealand, and South Korea all show relatively low rates of COVID-19 per capita, as well as high levels of testing. Conversely, countries like Spain and Kuwait reveal high levels of confirmed cases per capita and extremely low testing rates.

Another Perspective for Good Measure

For a holistic view of testing, the map below shows us the daily number of tests for each newly confirmed COVID-19 case, based on a rolling 7-day average.

Countries like Norway, Australia, and Canada reveal strong testing-to-confirmed-case ratios. In contrast, countries like Bolivia and the Philippines reveal the probability of out-of-control outbreaks.

Due to lower levels of testing in relation to confirmed cases, countries in red are more likely to leave cases unreported.

Making Sense of the Unknown

Although charts like these allow us to look at relationships between critical variables, there are no guarantees of what will come of this outbreak or any second waves.

The only certainty right now, is uncertainty. But with visualizations like this one—updated daily—we can at least stay up-to-speed with the knowledge curve.

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