Reply To: How Is It Spreading

  • Thu, Mar 26, 2020 - 02:53pm



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    Reply To: How Is It Spreading

Without doing the math properly,  if it is working, I would expect to see a decrease in new cases between 14 and 21 days, here is why.

If we assume:

An average of 7 days between infection and maximal infectivity (symptomatic)

One person from every household which will ultimately be infected is infected on day 0.

That households are isolated, i.e. transfer within households only, no cross contamination between households.

X number of people get infected at day 0, and each of their households contains y people, which all get infected, and have a 7 day lag.

The peak of the first round of infections will occur at day 7, x cases, when they pass the infection on, 7 days later (day 14) there are x*y cases, i.e. still in exponential growth at day 14, but this should be the peak. Of course there is a delay between becoming symptomatic and getting test results, hence the upper end of 21 days.

In fact we in a week or so we should be able to get a good estimate of the proportional R0 value in Italy after the containment was imposed. With a bunch of assumptions of course. We could probably do it now for SK.


Also, there is noise in the data but since the 21st or so it looks like Italy has broken exponential growth, assuming there reporting has not changed.