Thread by @dhmontgomery

It’s been just over two weeks since most Minnesota kids returned to school, and the data has become quite clear: the school #COVID19 surge many people expected is here.

Minnesotans aged 10-19 are seeing the highest rates of new infections right now, which is unusual — over the whole outbreak, it’s been working-age adults who’ve tended to have the most cases.

Unclear how much of this is an artifact of expanded testing, though.

Minnesota does not break out its daily testing data by age. We know testing has drastically expanded in Minnesota in recent weeks, and more testing confirms a higher share of infections that were there whether we knew about it or not.

Overall, while raw *case counts* have risen the past few weeks, *positivity rate* — which controls for testing volume — has been mostly flat.

And we know that historically cases in children have been less likely to be confirmed by tests (in part due to less severe symptoms).

So it’s possible that part of what’s happening is expanded back-to-school testing is catching a higher share of pediatric infections.

But the recent rise is not JUST driven by children. Cases are up in all age brackets, and hospitalizations — a good proxy for serious cases — continue to rise.

The second chart here was mislabeled due to haste. It shows total cases per capita by age since August 2020. Correct version attached:

https://twitter.com/dhmontgomery/status/1440719914763911176

Positivity rate and hospitalizations are both growing at a very slow pace, so there aren’t really signs that we’re seeing a new takeoff of infections. Rather, so far, it’s more cases are shifting to a group (kids) that previously wasn’t likely to show confirmed cases.

.@mnhealth DOES track testing data by age, but they only release it

A) once per week
B) as cumulative totals
C) in a damn *PDF*

@mnhealth Looked at as a share of total cases, rather than weighted per capita, you can see how Minnesota’s case makeup is shifting toward children over the past few weeks:

@mnhealth I’m going to delve into this more in my @MPRnews #COVID19 newsletter later today or tomorrow, so subscribe if you’re not already: mprnews.org/newsletters

@mnhealth @MPRnews I laboriously rescued a few months of Minnesota’s testing data by age from @mnhealth’s PDFs.

Two striking things:

1) Kids have the highest positivity rate of any age group in MN
2) This was a development in JULY & AUGUST, not since Labor Day.