On the other side of Omicron

Wisconsin is now a couple weeks past the peak of the Omicron wave. Compared to last winter, the Omicron peak had about double the daily rate of cases; not quite the same rate of hospitalizations; but less than half the rate of deaths.

The peak rate of new infections happened about one week into January. This was not too clear at the time, because the unprecedented number of cases created a big backlog in state reporting. Then DHS flipped some switch on the 16th and cleared it (was that switch there the whole time?), flooding graphs everywhere with cases. Now that the dust has cleared, though, looking at cases by date of test return makes it clear the peak was at least a week earlier. Here are cases by day of report (including the big backlog dump), and positive tests by day of test result.

Cases by report date

Positives by test result date

What proportion of these cases are Omicron, and what proportion are Delta? Delta started declining after Thanksgiving and Omicron has entirely taken over, incredibly rapidly. If Omicron hadn’t shown up, I think Delta would have still petered out on its own, but probably not as rapidly.

Cases by variant

Despite the deluge of cases, the rate of new hospital admissions topped out at a bit below last winter’s peak, and is now declining as well. A different measure of hospitalization, the total number of people in the hospital at one time, reached just four patients higher than last winter’s peak and is also declining.

Hospital admissions

Hospital patients

The outlook on deaths is also encouraging. Now, I don’t trust that the plot below is really complete yet, because more death reports will filter in over the coming weeks. But it has been a long enough time that I don’t think it will change drastically. So duly caveated, the peak rate of deaths from Omicron was not even half of the rate from last winter, and in fact may end up lower than the peak of Delta deaths from the previous month.


Overall, compared with last winter, Omicron brought us two times the peak of cases, a notch fewer hospitalizations, and less than half the deaths. Still a crappy Christmas present, but thankfully it did not turn out as badly as it might have.