Blogger's Note: Steve Thode has been tracking the pandemic since its inception. In his latest report, he compares the COVID-19 surge last winter with this winter. As we all know, this winter was much worse.
Here is a recap of the Winter 20-21 and Winter 21-22 COVID surges in Lehigh and Northampton counties combined.
I'll recap using three charts.
The first chart is a comparison of the 7-Day New COVID case rates for the time period December 4 to February 16 for each winter. Here's the chart:
During the winter of 20-21, the 7-Day New Case rate peaked at 4,349 new cases reported on January 12, 2021; during the winter of 21-22, the 7-Day New Case rate peaked at 17,266 new cases reported on January 11, 2022. So, the winter peak in 21-22 was nearly four times as high as the winter peak in 20-21. After the peak, 7-Day New Case rates dropped rapidly this winter, declining to 3,375 reported on February 1 - a drop of more than 80% from the peak. Since cases are reported as of midnight the day before, the February 1 report is as of January 31. I declare the Winter 21-22 surge ended on January 31, 2022. As you can see, the 7-Day New Case rate has continued to decline rapidly. As of Wednesday, February 16, the 7-Day New Case rate has dropped to 816 - a decline of more than 95% from the peak; and, the lowest 7-Day New Case rate since August 10, 2021. Last year, the 7-Day New Case rate didn't drop to 816 until May 11, 2021.
How deadly were the Winter 20-21 and Winter 21-22 COVID surges? I present two charts.
This next chart is Cumulative New Cases beginning on December 4 of each winter through January 31 of each of each winter; and, Cumulative New Deaths beginning and ending 10 days later (assuming a lag between a positive COVID test and subsequent death). Here's the chart:
Over this time period, the Winter 21-22 surge produced more than twice as many new cases as did the same time period during Winter 20-21. However, this winter's surge produced substantially fewer deaths than last winter. Over this time period last winter, approximately 1.85% of those who tested positive subsequently died. This winter, the death rate was 0.61% over this time frame. So, this winter the mortality rate was only about 33% of the mortality rate last winter.
The above chart and stats are a mixture of Delta and Omicron cases and deaths this winter. So, let's focus on the Omicron segment of this winter's surge. No one knows exactly when Omicron became the dominant variant, but most authorities suggest it was sometime in mid-December 2021. Looking at the data on reported cases, the number of new reported COVID cases became consistently higher this winter than last winter on December 17, so I have chosen to recast the data from the previous chart using December 17 as the start of the "Omicron Surge" in cases; and, December 27 as the starting date for "Omicron Surge" deaths. Here's the chart:
For this time frame, new cases reported in Winter 21-22 were almost two-and-a-half times the number of new cases reported in Winter 20-21. Meanwhile, recorded deaths were substantially lower. Over this time period last winter, approximately 1.86% of those who tested positive subsequently died. This winter, the death rate was 0.57% over this time frame. So, the "Omicron Surge" this winter had a mortality rate that was only about 31% of the mortality rate during last winter's "Delta Surge."
As always, some data limitations are in order. The actual number of positive COVID cases this winter was likely much higher than the reported number due to: the wider availability of home tests (some people got a positive result from a home test but suffered only mild or no symptoms and didn't report the result); and, the number of people who contracted COVID but were asymptomatic and didn't get tested.
As for using using a 10 day lag between reported cases and recorded deaths, we know some deaths occur soon after a positive test while some deaths may occur weeks after a positive test. However, as far as I know, no one reports the actual time frame between diagnosis and death for those who died from COVID. I did try using different lags, but all showed essentially similar death rates.
Finally, I will note that the number of recorded deaths through February 10 for this winter's surge may be subject to a minor upward revision due to possible delays in recorded deaths. However, both the Lehigh County Coroner and the Northampton County Coroner have been quite prompt in recording COVID deaths.