Public Health announced today that the transmission rate of COVID-19 is no longer falling and may be rising again in Western Washington, according to the latest report from Bellevue-based Institute for Disease Modeling (IDM). Full post available on Public Health Insider here.
Otherwise, this daily synthesis of the Public Health data is provided by Will Daugherty of Pacific Science Center. Thanks Will!
Public Health has updated the data dashboard. As of 11:59 pm yesterday, May 7, there were 6,940 confirmed cases of COVID-19 in King County, 77 more than the previous day. There have been 485 confirmed deaths in King County due to COVID-19, 7.0% of all confirmed cases.
The numbers that Public Health reports each day include delayed results from previous days.
The three graphs below chart new cases, total case count and the logarithmic trajectory of cases.
The first graph shows new cases (blue bars) and the 7-day average (red line). Of the 77 cases reported today, 65 were confirmed yesterday and the remaining 12 were confirmed in previous days. The 7-day average of new cases per day peaked at 191 on April 1. The average for the last 7 days remains at 78 new cases per day. How can the trailing 7-day average remain at 78 when the red line shows a clear decline in the last few days? Because Public Health new cases to the totals for previous days.
The second graph shows the total case count. With 6,940 total cases as of 11:59 pm yesterday, the compound daily growth rate during the last 7 days has been 1.2%, slightly less than the 1.4% rate during the prior 7 days. If we start with 6,940 cases, a 1.2% compound daily growth rate (1.173% to be precise) yields 81 new cases in a day, 590 new cases in a week, and 2,680 new cases in four weeks. In order for the number of new cases per day to fall below 10, the compound daily growth rate will have to fall below 0.15%. I don’t see this happening in the month of May considering how elongated the decline in the 7-day average has become (red line in the first graph).
The third graph shows the trajectory of cases in King County with the total number of cases on the horizontal axis and the new cases on the vertical axis. Each axis is on a logarithmic scale. Each blue dot represents a daily report. The dot farthest to the left is the February 28 report. Time passes from left to right as the total case count grows. The dot farthest to the right is today’s daily report. We can see a clear change in the trajectory since March 28, shortly after Governor Inslee’s “Stay Home, Stay Healthy” order on March 23.
Will Daugherty welcomes your questions and comments. His email is email@example.com