California COVID-19 Case and Testing Statistics
As of Friday April 03 2020, California had 10,701 cases of COVID-19. Over the past week, California was finding 975 new cases per day on average and recording 22.7 deaths per day. Data for California is provided by the COVID Tracking Project and will be updated daily. The COVID Tracking Project gives California a data quality grade of: B
California average daily new cases
The chart below shows the trend of new case discovery for California. Flattening the curve of new daily cases will help alleviate the burden on hospitals and healthcare workers and help ensure that patients that need critical care can get it.
Note: If testing is insufficient the above curve will underrepresent true case discovery. Nationwide daily testing per million residents is currently 336.1. Reported California testing per million residents per day is 50.8. California testing may be underreported or insufficient relative to the US as a whole.
California average daily deaths
Deaths from COVID-19 are likely better reported than the true number of positive cases. As a result, the trend in average daily deaths from COVID-19 might be a more telling measure of progression through the outbreak than daily average positive cases.
Statistics for positive cases of COVID-19 in California
Total Cases and Total Cases per 1M residents are cumulative counts. Daily Positive measures are rolling 7 day averages.
Death statistics for COVID-19 in California
Total Deaths and Total Deaths per 1M residents are cumulative counts. Daily Death measures are rolling 7 day averages.
COVID-19 testing statistics in California
Testing metrics for California are too low for me to have faith that they are being accurately reported. I'm only reporting testing statistics for states with an A data grade from the COVID Tracking Project that test at a rate of at least 100 per million residents per day. California is either not testing at that level or is not reporting their testing fully.
A final word on this analysis
In order to manage the outbreak, states need to increase their testing capacity. As testing increases, the number of detections as a fraction of total tests (positive rate) should hopefully decrease over time. If a state is able to test widely enough (at least 300 tests daily per million residents, probably more) to drive the positive rate down (less than 5%) there may be the potential to manage a regional outbreak with isolation, contact tracing and quarantine South Korea has.
Please take my calculations and amatuer epidemiological speculations with a huge grain of salt as I'm moving quickly to get what I hope are meaningful measures online. There may be errors in my data and my thinking!
Last but not least, thanks to the folks at COVID Tracking Project for making this data available to everyone.