Masks
A small study showed that masks did not reduce viral spread from a cough. Apparently the force of coughed air moves aerosol around the mask instead of depositing it on the mask. The study did not look at whether a mask protects wearers from coughs by others. It also did not test N95 masks.
Why 'Test & Trace' won't work in NYC Metro area.
New York Governor Cuomo has stipulated the implementation of 'Test & Trace' as a condition prior to reopening New York. However, the numbers show that is a fool's errand.
Antibody studies of the NYC Metro show that about 20% of the population have been exposed and recovered from the virus. However, confirmed cases only make up 2% of the population. This data suggests 9 of 10 with the virus have no symptoms or have such mild symptoms that they are not tested. Of the 18% asymptomatic population (9 of 10 with antibodies), about 80% of them stayed-at-home for the last 5 weeks. Assuming they were in an average household of three and they took no precautions to protect others in the household because they had no symptoms, those household members are undoubtedly infected. That computes to another 36% who are infected and who presumably would have the antibodies in another few weeks.
The 20% of asymptomatic people who could not stay-at-home for various reasons, have been interacting with the public for five weeks. With all of the precautions in place, let's assume that the reproduction factor is only 0.5 (only one in two infectious persons transmits the virus to one other person). That is less than the apparent reproduction rate of 0.9 (see NYS data). In other words, I am saying that the real people transmitting the virus are not the people working, but people in their homes, transmitting it to other household members. That matches case data from China. If the serial interval is five days (see DHS data), then three weeks from now this group will have infected a number equal to themselves. It is a relatively small number (4% of total population). If you add up all of these numbers, you have 20% (antibody tested positive) + 36% (infected by asymptomatic persons in the household) + 4% (infected by asymptomatic workers) = 60%!!
This analysis is supported by the virus test results. No matter what the testing volume, the percent positive in the NYC metro area is about 30% right now. But we know 20% have the antibody. That means 50% either have the virus or have the antibody (it is possible, but unlikely to have the IgG antibody and the virus at the same time). That is very close to the 60% estimate above.
The bad news is that if the virus is that contagious and that wide spread, you will never be able to test and trace all of the people exposed in a population of 20 million.
The good news (if this analysis is correct) is that the virus has just about burned out in the NYC Metro area. Assuming 20% are naturally immune for some reason or another (drugs they are taking, genetics, blood type????), then only another 20% of the people in the NYC Metro area are yet to be infected. If we continue the social distancing, it will drag out the time needed for the last 20% to be exposed. For Westchester, I predict that will be another 13 weeks! (Aug 1). Westchester is testing about 1% of the population every week. In 13 weeks, 24% of the population will have been tested. At the current rate, about 8% of the population will have been confirmed positive (currently about 3% are confirmed positive). If the real rate is 10 times the number of confirmed, then 80% will have been infected at that point, which is eveyone who could be infected.
It should be obvious by now that if the virus is that wide spread in the NYC metro area, that cutting back on social distancing will not have a drastic effect on hospitalizations. There are not that many people remaining to be infected!
Redoing the antibody test in another 2 weeks would prove or disprove this analysis. I suppose I am patient enough to wait that long.
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The 'noise' in new cases is so great that I am only showing the 7 day averages. The noise is caused by daily changes in testing volume. As stated above, New Cases and Number of Tests is strongly correlated. The more you test, the more you find.
Westchester deaths per day is still about 30 (orange line).
Bergamo, Italy has had a steady stream of about 50 New Cases per day. Social distancing there is still in effect. My estimates are that this area is also about 'burnt out' with the virus.
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