April 29 - COVID-19 in Westchester County, NY

We are 43 days into the "Slow the Spread" initiative, 50 days since the containment zone in New Rochelle, 57 days (Mar 3) since the first case in New Rochelle (Westchester) was confirmed, and 67 days since that first case had symptoms (Feb 22). If you are like me, it is starting to get old.  I no longer watch Cuomo at 11:30 or the White House Briefings at dinner.

Just the same, I would like to know what is going on.  Something about virus transmission and lethality does not make sense.  It has become evident that the virus is very widespread in Westchester and less lethal than originally thought.  How and when did it spread so fast? Was it via fomite or aerosol? Were there tens of thousands with the virus circulating prior to the first case being detected? And why was the transmission rate so high even after social distancing?

New Cases in the NYC Metro area (including Westchester) seem to be in more than a linear decay. All of these areas show a similar trend in the last four days.

Neither a Gaussian shape nor a linear decay do a good job of matching the trend of the epidemic.

Deaths in Westchester appear to be declining.  Fitting the data to a Gaussian curve seems appropriate.The early death reporting (spikes) was gathered from press briefings prior to NYS making the data publicly available on a daily basis.  The early data is presumed to be both under-reported (late) and accumulated over several days (instead of a single day).

The IHME model also assumes a Gaussian shape for the Death Curve.  They have found that slowing the spread widens the curve, but does not reduce the area under the curve.  In other words, the same number of people die, they just don't die all at once and flood the hospitals. To account for that recent finding, IHME has changed the models (which are very dependent on recent actual data) so they predict MORE deaths than prior models.  Here is the latest model for NYS.  It predicts that by May 8, deaths will fall below 60 per day (~2% of total deaths). This is the same date as the April 22 model.  On April 1, their model had 95% confidence that the death rate would be 0-50 on May 1!

Reopening Westchester

The Westchester County Executive has not announced any plans for reopening.  He did mention that he plans to go ahead with Bike Sunday on May 3, but with face-covering required.  Bike Sunday is a 6.5 mile shutdown of the Bronx River Parkway for four hours on Sundays in May, June, and September.

His hands are tied because the reopening of Westchester must be done in conjuction with NYC and other NYC metro areas.

Here are the latest NYS requirements for reopening.