Contrary to every formal prediction, the U.S. Omicron wave continues to fade away. Today the U.S. stands at 12 new COVID-19 cases per 100K population per day, down one from a couple of days ago.
Deaths remain around 350 per day. Hospitalizations are approaching half of what they were at the mid-August 2022 peak.
Source: CDC COVID data tracker accessed 10/8/2022.
Data source for this and other graphs of new case counts: Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 10/8/2022, from https://github.com/nytimes/covid-19-data.” The NY Times U.S. tracking page may be found at https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html
Alpine wave?
It’s still hard to say whether the existing north-south differential in new case growth means anything or not, in terms of a U.S. winter wave.
Four days ago:
Today’s data:
I would say that, by eye, that’s no sharper today than it was four days ago.
Meanwhile, in Europe, if you look at the countries surrounding France and Germany, it sure looks like this is an alpine winter wave. That is, the countries that share the Alps all have started a winter wave. Adjacent countries that don’t abut the Alps are showing nothing of the sort.
Source: Our World in Data, accessed 10/8/2022
But that’s kind of nuts, as not many people live in the mountains. Unfortunately, I can’t lay my hands on sub-national data to see whether or not the higher-elevation areas in those countries are leading the wave.
The thing to keep in mind about high-elevation areas is that not only do those tend to be cold, there just ain’t as much oxygen there. Once you get to an altitude of, say, Boulder CO, the partial pressure of oxygen is about 25% below where it is at sea level (reference).
That, of course, matters greatly for upper respiratory infections, particularly among the elderly. What might be a modest reduction in blood oxygen saturation at sea level can becomes a life-threatening situation at 6000 feet. This shows up clearly in Medicare claims (billing) data, where oxygen use in the Rocky Mountain states is several multiples of oxygen use in (e.g.) the coastal states.
And the reduced oxygen in high-altitude states has long left its footprint on ICU use among hospitalized COVID-19 cases. Below are two graphs from last year’s (2021-22) U.S. winter wave (Post #1391). It shows the striking correlation between elevation above sea level, and ICU use (meaning, by and large, ventilator use) among hospitalized COVID-19 cases.
Looking at Europe, and looking at the current U.S. map below, I wonder if we’re going to have a wave centered on high-elevation areas this year. If you squint just right, you can kind of see the Rockies (and to a lesser extent, the Appalachians) outlined in darker blue.
Otherwise, I still believe that the prime driver of our usual wintertime increase in respiratory infections is dry indoor air. I went through all that in Post #894.
Here in Virginia, the dry indoor air season hasn’t started yet. Indoor relative humidity in my (leaky, old) house remains over 60%, well into the safe zone. So if dry air is the driver for the winter wave, my guess is, that hasn’t happened yet in most of the U.S.
