Coronavirus spreads. But don't panic! (topical thread)

[Dānu]

Why outbreaks like coronavirus spread exponentially, and how to “flatten the curve”

This so-called exponential curve has experts worried. If the number of cases were to continue to double every three days, there would be about a hundred million cases in the United States by May.

That is math, not prophecy. The spread can be slowed, public health professionals say, if people practice “social distancing” by avoiding public spaces and generally limiting their movement.

Still, without any measures to slow it down, covid-19 will continue to spread exponentially for months. To understand why, it is instructive to simulate the spread of a fake disease through a population.

We will call our fake disease simulitis. It spreads even more easily than covid-19: whenever a healthy person comes into contact with a sick person, the healthy person becomes sick, too.

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To slow simulitis, let’s try to create a forced quarantine, such as the one the Chinese government imposed on Hubei province, covid-19’s ground zero...

...As Lawrence O. Gostin, a professor of global health law at Georgetown University, put it: “The truth is those kinds of lockdowns are very rare and never effective.”

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Let’s see what happens when a quarter of our population continues to move around while the other three quarters adopt a strategy of what health experts call “social distancing.”

...Even with different results, moderate social distancing will usually outperform the attempted quarantine, and extensive social distancing usually works best of all. Below is a comparison of your results.

[Brown are sick people, purple are recovered people]