COVID-19 Estimated New Cases Trend Watcher

Blue: good news, Red: bad news, Grey: no change 🛈

Blue: decreasing new cases (good news)
Red: increasing (bad news)
Grey: same number as day before (no change)

Inner circle: new cases per day, darker colours mean bigger decrease/increase compared to the day before
Border: 3 day trend, darker colours mean decrease/increase has been going on longer

Blauw: goed nieuws, Rood: slecht nieuws, Grijs: geen verandering 🛈

Blauw: afnemend aantal nieuwe gevallen (goed nieuws)
Rood: toenemend (slecht nieuws)
Grijs: zelfde aantal als de dag ervoor (geen verandering)

Cirkelgrootte: nieuwe gevallen per dag, kleiner is minder en groter is meer
Cirkelkleur: vergeleken met de dag ervoor, donkerder betekent een grotere af-/toename
Cirkelrand: driedaagse trend, donkerder betekent dat de af-/toename langer gaande is


days days %

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Explanation 🛈

In short: since the actual number of cases may differ greatly from the registered cases (symptoms not recognized, different registration approaches between countries, availability of testing kits, ...), we take the confirmed deaths as a more precise indicator.

For instance, let us assume an incubation period of 5 days (currently experts say 5-7), a symptom onset to death period of 15 days, and a mortality rate of 1%. Now suppose 1 person died on 31 March, this death would be the result of an estimated 100 new infections 20 days (5 + 15) earlier, on 1 March.

So suppose the mortality rate is x%, the incubation period is y days, and the time between first symptoms and actual death is z days, every confirmed death on one single day would be the result of 100 / x new cases, (y + z) days earlier.

For further explanation of the modeling behind estimated new cases, see Khan Academy on YouTube.

Note that with this model, new infections show up earlier on the map than when based on real reported cases. This is because the real reported cases are first recognized when people get sick, i.e. have symptoms that are recognized as COVID-19 related. This means that the estimated new cases map runs ahead of the reported new cases map, because the estimated new cases map shows estimated new cases as soon as they supposedly have been infected.