COVID-19 Interest Group
April 13, 2020
Arlin‘s Corner #3 April 13, 2020
The data, information and estimation of future cases presented below is based on public data and my own personal mathematical analysis of it. It has not been peer reviewed and has not been officially endorsed by the Berkeley Rotary Club. It is a brief summary concentrating on today's Covid19 situation in the Greater Bay Area and Alameda & Contra Costa Counties. If you have any questions, please call me at 510-501-0298. If you are interested in a copy of my Excel spreadsheet for the analysis of GBA or A&CC data, please e-mail me at email@example.com......Arlin Peters
This issue of Arlin's Corner concentrates on whether we have reached a turning point in the Bay Area. There are hopeful signs that answer is yes, but it may be just a plateau.
There is lots of jargon below : GBA is Greater Bay Area, 7 counties with 7.1 million population. Alameda Co is 1.66 million, Contra Costa is 1.15 million. DT is doubling time, the number of days for confirmed cases to double, it's important in the early stage of a wave of infections., before a peak in the daily number of new cases. Confirmed cases are people seeking medical attention who have subsequently been tested positive for the CoV2 virus.
On Sunday April 12, the GBA had 129 new cases bringing the total to 4993 confirmed Covid-19 cases or 703 cases per million (cpm). Over the previous 6 days, the number of new cases averaged 207 per day. The GBA is past the peak of ~260 new cases per day reached on April 3, and is in a plateau of 200 to 225 new cases per day - or possibly declining. The GBA doubling time (DT) has been steadily increasing from 9 days a week ago, to 16 days on Easter Sunday. This is due to everybody’s diligent hygiene and social distancing behavior and other factors such as a large number of “hidden” asymptomatic and mild to moderate untested Covid-19 cases may play a part.
On Saturday April 11, Alameda and Contra Costa counties had 45 new cases bringing the total to 1382 confirmed Covid-19 cases or 493 cpm. Over the previous 6 days, the number of new cases averaged 62 per day. A&CC is past the peak of ~90 new cases per day reached on April 2, and is in a plateau of 60-65 new cases per day - or possibly declining. The A&CC doubling time (DT) has increased from 11 days a week ago, to 15 days on April 11.
On Saturday April 11, Contra Costa County had 9 new cases bringing the total to 539 confirmed Covid-19 cases or 463 cpm. Over the previous 6 days, the number of new cases averaged 24 per day. We are past the peak of ~37 new cases reached on April 3, and are in a plateau of 20 to 25 new cases per day - or probably declining. The CC doubling time (DT) has increased from ~6.5 days a week ago, to 18 days on April 11.
For comparison, The US on Sunday April 12, had 28,900 new cases bringing the total to 555,300 confirmed Covid-19 cases or 1680 cases per million. US case data is dominated by New York and New Jersey, which have a combined 250,000 cases, 45% of the total! Over the previous 6 days, the number of new cases averaged 31,400 per day. The US new cases per day probably has not peaked, but maybe flattening due to NY &NJ. The US doubling time (DT) has been steadily increasing from 6.5 days a week ago, to 10.5 days on Easter Sunday.