April 19 - COVID-19 in Westchester County, NY

The usual charts are shown below followed by a discussion on mortality rates and reproduction rates.

The New Cases in Westchester County are within the same range (700-1000) as in the previous 25 days. Note that most entire states do not have that many New Cases per day! The "spread" or duration of the outbreak is longer than predicted by most models.  It is much longer than the Wuhan event (if you believe their data).

But the duration of the epidemic in Westchester may not be that much longer than Bergamo....yet!  The orange line is a fit of the Westchester data using the Bergamo duration.

If there is any good new it is that the Percent Testing Positive appears to be decreasing despite high  testing volumes.

The death rate (Orange Line) also appears to be trending slightly downward.  Note that this is a logarithmic plot.

Mortality

The White House Task Force Briefing showed a slide that Dr. Birx referred to as "Case-Fatality-Rates", but it was really a Population Mortality Chart.  Case Fatality is how many diagnosed people die. If more people are diagnosed because you are testing more, then your Case-Fatality should go down, because you are catching more of the mild symptomatic or asymptomatic cases. In NY the testing has been at a per capita rate much higher than the rest of the world so the case fatality would be expected to be lower than a country where diagnosis was by symptoms rather than a test or where only the very sick were tested.  In other words, COMPARING CASE-FATALITY-RATES IS DECEPTIVE.  Below are the Case Fatality data for major impacted countries.

The Population Mortality Rate is the deaths per capita.  This is also deceptive because most COVID deaths have comorbidities.  The cause of death can depend on the practice of the national health authority.  Which of the comorbidities is the major one? Or is it counted as a COVID death if any one of the comorbidities is COVID? (That is the US policy).  The rate is also a factor of how the country was able to slow the spread. It is doubtful in any case that the virus is 'Contained', only slowed.  For many of these countries, including the US, the pandemic is far from over.  More people will die and the rates will go up.  The population mortality rates in NYC (106) and Westchester (70) are much higher than the country at large because of the extent of infection.  Once again, the data are interesting, BUT DECEPTIVE.

White House Briefing Chart of Population Mortality

John Hopkins Chart of Population Mortality

Reproduction Rates

Reproduction rates are a measure of the contagion of the virus. A rate of 2 means that one person infects 2 new people.  A rate greater than one is an epidemic. Rates change based on region, weather, social distancing and other factors. Like the case-mortality-rates and population-mortality-rates, this rate can also be deceptive.  New York Governor Cuomo referred to the "New York Reproduction Rate" several times in his Briefing yesterday. Many of his assertions are very shaky.  Here are some of his statements and my response:

1. "We brought the reproduction rate down to 0.9 by distancing measures" - This is a bogus mumber based on confirmed cases.  What about all of the asymptomatic cases that remain invisible? Even if the rate is 0.9, what measures really got it there?  Maybe it was just closing all of the gyms and public transportation? (and not all of the other mandated closures.)  Or maybe none of the measures had any effect? It is unlikely, but maybe this is the natural course of the virus? There is no study to confirm that this "correlation is causality." (as Dr, Fauci would say)

2. "A reproduction rate of 1.4 is where we were at with no distancing measures" - Once again this is based on the initial testing which totally underestimated the spread of the virus in Westchester and the NYC area.  Others estimate the reproduction rate to be closer to 6 in a dense environment like NYC and lower Westchester..

3. "Reproduction rate of 1.2 would be back where we were" - As above, these numbers are all bogus. Cuomo is really putting too much value in the wrong numbers. The objective should be to keep the hospitalization rate manageable no matter the reproduction rate.  For example, right now the new case rate (ie. reproduction rate) is still quite high but fewer are being hospitalized.  Has he tried to understand the reason for that?

4. "Testing is the answer" - This assumes that people have a reason to get tested.  If you have no symptoms, which is common with this virus, you will not be tested, but will be a spreader. For the time being (until every NYer can get an instant test, which will never happen), one must assume they are positive and that everyone around them is positive. Antibody testing might be a partial answer, but Cuomo did not talk about that.

5. "Contact tracing is the answer" - In the NYC metro area, where people use mass transit, contact tracing is nearly impossible.  If the virus is spread by touch of hard surfaces, contact tracing is not feasible. It is foolish to place hope is this method of containment.  See example below.

6. "We contained the cluster in New Rochelle through contact tracing" - New Rochelle and its vicinity in Westchester County blew up into the hottest area in the country.  There were more cases per capita than New York City. Contact tracing did NOT snuff out this cluster! In fact, it had NO apparent effect on the trajectory of the epidemic in Westchester, which was disastrous!