updated. here is in my opinion the most interesting/significant update
my original methodology for calculating an estimated true case load for the most recent 2 weeks broke down with the most recent data, so i adjusted how i handled that and changed the methodology description below to match the new graphs
(updated 4/3/2020)Methodology: To come up with these estimated true case load curves, I assumed the death count trails the true case count by 2 weeks, so I took the death total for each day, and use that and the assumed CFR to estimate what the total true case load was 14 days earlier. For the 2 most current weeks, where 2 week out death numbers are not available, I used forecasts for the death count over the next two weeks to calculate and estimated true case load. i indicated on each curve where the calculation starts being based on forecast rather than real data. since we are seeing death count bend over slightly and not lie on an exponential curve over the last 12 days, I used two possible curve fits for the death count forecast, a 2nd order polynomial and a power law curve. My personal opinion is the power law curve will ultimately be a better forecast due to its better match to the shape of the last 12 days worth of the real curve, but I went ahead and included the poly curve as it also is a decent fit and should represent the most optimistic (while being realistic) outlook on future death count numbers. I also added a CFR of 1.75% since that is what S. Korea is trending towards at nearly 1% of their population tested and 60% of their total cases having resolved already. and my observations from this look are:
- First, 0.022% and .0082% CFRs for power law and poly curves respectively iare currently the absolute lower limits for possibilities, because this means that every single person in the USA currently has been infected by COVID-19. So not the lowest feasible CFR, but the lowest that is physically possible.
- in all but the really deadly CFR scenarios, we have already surpassed last year's flu numbers in estimated true case counts 7 weeks into the season despite flu having a 600k case head start.
- I also added some population % lines at points that are relative to thresholds of infection percentage estimates from past pandemics.
death forecast curves for reference: