Don's Home Health | Pandemics Coronavirus Pandemic (Covid-19) Contact
Other Pages: Case Fatality Rate (CFR) | Treatment-Vaccine | Coronavirus Safety - Prevention - Treatment | Personal Protection Equipment | Coronavirus Facts | Vaccines
last updated 23 November 2020
Some data only updated once per week.
Daily data is 7 day averages.
Click on charts to get the current versions.

Contents: The Numbers: World | Latin America | Asia | Case Positivity Rate | US | Epicenters | Florida | New Jersey | Some State & City numbers | California | North Central California | Tahoe | Yolo County | Placer County | Santa Clara County | Facts about covid-19 | Safety Prevention | What is the real number of infected people? | Sources | Good Twitter feeds

I was tired of the media only reporting total cases, it's meaningless for me. 1,000 new cases in Nevada is significant, 1,000 in California is not.
I want to know the probability of meeting someone in the grocery store with coronavirus. To get that I need the Attack Rate, how many people are infected per 100,000 population.
I have gone thru several iterations concentrating on death rates in the beginning because of the lack of testing.

Joshua SA. Weitz at Georgie Tech developed a tool to assess the risk that one (or more) individuals in a group was infected which was documented in nature research in October.
. You specify the group size and an ascertainment bias of 5 or 10. i.e. actual infections are 5 to 10 times higher than what is reported.
See COVID-19 Event Risk Assessment Planning Tool
and Substantial underestimation of SARS-CoV-2 infection in the United States | Nature Communications Sept 2020.

We are concentrating on trends now from the world down to some towns in California. Where are the outbreaks, relative size of the them, history of safety plans etc..

World Stats:
Click on charts to get a current version.

Coronavirus Dashboard |

* New cases and deaths are 7-day moving-average

Click on Charts to go to the current version.

Regional share of daily confirmed cases:

Although the number of deaths per million in Asia is still fairly low (< 1 to 4) their share of the total is larger because of total population.

Case Rate Nov 20, 2020
Region Population New Cases New Cases
per Million
US 331,000,000 169,865 513
Europe 747,636,026 262,000 350
Latin America 653,962,331 56,000 86
Middle East 411,000,000 24,000 58
Asia 4,641,054,775 62,000 13
Africa 1,347,333,004 14,000 10

November 20

November 5, 2020
This is a chart of the 25 countries, out of the 125 largest countries (population > 5 M), with the highest incidence of total corona infections per capita at the end of November. Plus a few like our neighbors Canada (rank=53), Mexico (rank=52) and world's largest, India (56), China (114), Russia (29). Other large countries Indonesia and Pakistan had low infection rate ranks 66 and 68 respectively.

NY Times Map



Test Positivity Rate
August 3
Experts advise looking at three measurements together: number of cases, case positivity rates and number of deaths to understand what is going on.
Test Positivity Rate is important because a high positivity rate probably means that the case count is low. See Positivity Rate.
WHO guidelines want it to be below 5%. When a positivity rate is higher, epidemiologists start worrying that means only sicker people have access to tests and a city or region is missing mild or asymptomatic cases.

Rates range from 50% in Bolivia to 0.4% in Australia
The US is at 8%
See Positivity Rate for more.

Daily tests per thousand

United States: November 20, 2020
Place Popu-
Cases Deaths Cases Deaths
Total New * Total New* % of
United States 331,000,000 12,341,101 172,205 261,051 1,481 3.7% 52.0 789 4.5
* New cases and deaths are 7-day moving-average

United States Coronavirus: - Worldometer

A Columbia University report states that as of October more than half of the COVID-19 fatalities in the United States were "avoidable". US's higher mortality rate is because of a confluence of factors, stemming from delayed responses, to missed opportunities, to inadequate guidance, coordination, and leadership. Each action – or inaction – had a substantial role in distinguishing the U.S. response from other developed nations.
South Korea and the U.S. both discovered their first case on January 20, 2020.
By March 16th, over 250,000 South Koreans had been tested – or about one in every 200 citizens. The U.S. didn’t reach the same proportional testing rate for several weeks until April 4th. 130,000 – 210,000 AVOIDABLE COVID-19 DEATHS – AND COUNTING – IN THE U.S. | National Center for Disaster Preparedness | Earth Institute - Columbia University

State and City cases and deaths per capita
  There are other measurements that would be helpful in understanding the progress of the epidemic in different places, such as the number of new hospitalizations, the number of tests administered or the number of people showing any symptoms of respiratory illness. But confirmed coronavirus cases and deaths, however incomplete, are the most useful daily statistics currently available at a local level everywhere in the country.
Hospitalizations and deaths lag cases by one to two weeks.

I've looked at places where I have friends and family or places which were considered hot spots in the news.
I moved back to California from New Jersey a couple of years ago. In April my friends in New Jersey had 10 times the chance of encountering a person with COVID-19 than I did in California. In July the numbers have flipped with California having 6 times and Florida 12 times the incidence of NJ.
By the end of November the average rate for the whole country was 5 times higher than it was in April.
See Epicenters below.

Florida Department of Health COVID-19 Outbreak

New Jersey Covid-19 Information Hub

The epicenters keeps changing:
Reopening sees surge in cases:
In April New York and New Jersey with the highest rates and California (largest population), accounted for 46% of all the cases in the country.

A surge after reopening in the South and Southwest changed the epicenter in July. Florida, Texas, Arizona and California accounted for 52% of all cases by July 15.

Hot Spots Bold - States 50% higher than national average. Not all listed.
State Daily New Cases
per 100,000
July 15 Sep. 8 Oct. 8 Nov 2 Nov 20
New York 51 4 6 7 10 25
New Jersey 39 4 6 8 18 43
California 3 20 11 8 10 27
Florida 6 56 13 12 20 37
Arizona 4 51 8 9 19 45
Texas 3 37 13 13 20 38
North Dakota 13 38 60 139 179
South Dakota 27 55 134 145
Wisconsin 14 15 43 80 117
Utah 20 13 33 55 116
Montana 31 77 124
Iowa 24 29 66 126
Idaho 37 16 28 45 82
Minnesota 12 20 46 128
Nebraska 14 29 60 125
US 10 20 10 15 24 50
South Dakota has a 19% positivity rate and 96% of ICU headroom is used.
It has almost 3 times the rate of the US and double the rate of the worst major country in the world.
Over 50% of people do not wear masks, yet Governor Kristi Noem refuses to issue a mask mandate as of November 20th. See AP story.
See Epicenters

CDC COVID Data Tracker

See Epicenters

California Nov 20

Place Popu-
Cases Deaths Cases Deaths
Total New * Total New* % of
United States 331,000,000 12,341,101 172,205 261,051 1,481 3.7% 52.0 789 4.5
California 39,510,000 1,072,272 10,800 18,557 62 2.7% 27.3 470 1.6
* New cases and deaths are 7-day moving-average

Click on Charts to go to the current version.

Tracking COVID-19 in California - ca-gov

See Case Fatality Rate

Coronavirus: 'Discrepancies' in California data as deaths rise August 5

California Department of Public health: California Coronavirus COVID-19 Response
Resilience Roadmap - Reopening Stages

COVID-19 | California Department of Public Health
California | The COVID Tracking Project

California Timeline: Mar 11 Non-essential gatherings must be limited to no more than 250 people, while smaller events can proceed only if the organizers can implement social dimerced cing of 6 feet per person. Gatherings of individuals who are at higher risk for severe illness from COVID-19 should be limited to no more than 10 people, while also following social distancing guidelines.

March 19 First state to issue a Stay at home order (Shelter in Place).
All individuals living in the State of California are currently ordered to stay home or at their place of residence, except for permitted work, local shopping or other permitted errands.
Essencial Services:

Essential state and local government functions Outdoor exercise is permitted with social distancing.

May 8 the stay home order was modified. In addition to essential activity, retail is allowed, along with the infrastructure to support it. California restaurants and shopping malls can soon reopen in counties that meet state standards for testing and success at reducing cases of the coronavirus,

May 26, 2020, Hair salons and barber shops will be allowed to reopen in 47 of the state's counties after being closed because of the coronavirus pandemic.

On June 12 most California Counties were allowed to move to Stage 3 with some indoor dining with table spacing, hotels, outdoor recreation and other facilities allowed to open.

Most Bay Area counties were still restricted.

Seven of the nine Bay Area counties have reported recent, significant upticks in cases, and the Bay Area as a whole recorded a nearly 40% jump in new cases
Source: Coronavirus cases on the rise across the Bay Area, especially in Alameda County -, May 26.

On June 18 as new cases in California continued to increase, the Governor announced masks were mandetory in high-risk settings where 6' separation could not be achieved.

On July 1 Governor Newsom announced 19 counties must close indoor restaurants, wineries, tasting rooms, movie theaters, family entertainment centers, zoos, museums and cardrooms for at least three weeks. If possible, those businesses can operate outdoors. Bars and breweries, indoors and outdoors, have been ordered to close..
Contra Costa, Fresno, Glenn, Imperial, Kern, Kings, L.A., Merced, Orange, Riverside, Sacramento, San Bernardino, San Joaquin, Santa Barbara, Santa Clara, Solano, Stanislaus, Tulare., and Ventura.

July 8 The state is monitoring data for elevated disease transmission (case rates and positive test results), increased hospitalizations and limited hospital capacity (availability of ICU beds and ventilators). Any county not meeting threshold criteria in at least one category goes on the watch list.
Marin was on the list and decided to halt indoor dining for at least three weeks in response. Santa Clara was no longer on the list but the previous restrictions remain based on having been on the list for three or more consecutive days.

July 13 Bars, indoor restaurants, movie theaters and many other recently reopened businesses across California are ordered to close.
29 counties on the state watch list must now close gyms, houses of worship, hair and nail salons, offices for noncritical work sectors, shopping malls and barbershops.
In the Bay Area, the more restrictive orders take effect in Contra Costa, Marin, Napa, Solano,Santa Clara and Sonoma counties.

July 17
Newsom releases requirements for schools to physically reopen for the new school year. Under the requirements, 90% of California’s K-12 aged children will begin the next school year doing distance learning.

August 28
Newsom unveils a new plan by which state officials will monitor California’s coronavirus hotspots, doing away with the previous system involving a watchlist of counties. The new system has four tiers of colors. Counties will fall into one of the four tiers, which will indicate what businesses can and can’t be open.
County risk Level New Cases/
Widespread >7 > 8% Many non-essential indoor business operations are closed
Substantial 4-7 5-8% Some non-essential indoor business operations are closed
Moderate 1-3.9 2-4.9% Some indoor business operations are open with modifications
Minimal < 1 <2% Most indoor business operations are open with modifications
Blueprint for a Safer Economy - Coronavirus COVID-19 Response

November 17
County Tier
Contra Costa  
El Dorado  
San Francisco  
San Joaquin  
San Mateo  
Santa Clara  
Blueprint for a Safer Economy - Coronavirus COVID-19 Response |
California Covid Map and Case Count - The New York Times

As of November 6th, Sacramento, Yolo, Placer and Stanislaus Counties were in danger of slipping into the Purple (Widespread) Level.

Bay area: November 10
North Central Califronia Counties Map

Other N California Counties of interest to me Nov 20:

New cases per day / 100K
United States  52 
California     27
Alpine Co.    150 (Lassen and Shasta
                were over 70 cases/100K
                with spikes in the last week too)
San Bernardino 56 


November 21
Place Popu-
Cases Deaths Cases Deaths
Total New * Total New* % of
United States 331,000,000 12,341,101 172,205 261,051 1,481 3.7% 52 789 4.5
New Jersey 8,882,000 313,863 3,855 15,0071 3.5% 43 1,690
California 39,510,000 1,072,272 10,800 18,557 62 2.7% 27 470 1.6
Yolo County 220,500 4,199 49 75 1.9% 22 340
Davis 70,560 485 5.0 3 0.7% 7 43
Santa Clara Co 1,928,000 31,603 328 467 1.6% 17 242
Palo Alto 64,372 367 n/a 0.6% n/a
Sutter 96,971 4,370 112 23 4.5% 115 237
Washoe Co, NV 471,519 22,407 359 246 4.8% 76 522
DuPage Co, IL 922921 41,602 692 703 4 4.5% 75 762 4.3
Sarasota Co, FL 433742 12,319 371 166 2.8% 86 383
1. New Jersey reports 2 numbers for deaths the official number is 10 times higher than another number called probable deaths. I couldn't find any explanation.

Links to County Dashboards.

Santa Clara
Santa Clara (Cases by Zip Code and City)
Yolo Co
Sutter Co
Solano County Public Health Dashboards
Coronavirus Report for Napa County, CA - LiveStories
Sarasota County, Florida | USAFacts
Washoe Co. NV


Some twitter feeds I found useful:
Coronavirus: The Most Essential People To Follow On Twitter During The COVID-19 Outbreak | Forbes
(2) Bob Wachter (@Bob_Wachter) / Twitter Chair, UCSF Dept of Medicine
Eric Topol (@EricTopol) / Twitter physician-scientist, author, editor, Sripps
@DrTomFrieden Former Director @CDCgov

Other Links:
Terms - Glossary