What new Utah coronavirus data says about schools and how the virus is spreading

(Rick Egan | The Salt Lake Tribune) Shoppers wear masks as they shop at the weekly Liberty Park Market at Liberty Park on Friday, Sept. 25, 2020.

Way back in June, I guaranteed you that when we got more data about the coronavirus in Utah, I’d tell you about it.

Well, Utah’s Department of Health updated its dashboard at coronavirus.utah.gov again. There’s a bunch of new graphs, with information on how the virus is spreading, which demographics are impacted most, and new detail about schools. Let’s explore the highlights and what it says about Utah’s recent spike in cases.

School data

In my last article about coronavirus in schools, I lamented the lack of data. Now, the state is releasing per-district case counts, giving us a better idea of how the virus is spreading. Of course, I really wish we had school-by-school counts statewide, like we do for Salt Lake County schools, but this is at least a step forward.

Here are the top districts in terms of case numbers. Any district not listed here has fewer than five coronavirus cases — the state’s reporting threshold for privacy reasons.

To have a case included here, the health department requires someone to be in person at a school for at least 15 minutes over the past 14 days. Since Salt Lake City School District is online-only at this point, it’s likely its small number of coronavirus cases are among staff and faculty.

We’ll want to keep track of the active cases count, to see if that rises or falls over the course of the school year. Right now, 1,119 of our 2,603 cases are active.

Of course, school districts are wildly different sizes in Utah: the Alpine School District is the biggest with 81,532 students from kindergarten through 12th grade, while the Daggett district has just 189 kids total. So what happens if you adjust for district size? Here’s that data, presented as one coronavirus case for every X students:

That’s a little bit simplistic, as 28% of confirmed coronavirus cases in schools aren’t from students, but from teachers (14%) and other support staff (14%). Given Utah’s student/teacher ratio, the adults in the room are facing higher per-capita case counts.

And the older kids are more likely to get it than younger ones. Take the data from Friday’s numbers, separated by kids age 5-10, 11-13, and 14-18 — approximately the cut-off for elementary school, junior high, and high school. The elementary school kids are far less likely to see confirmed cases than the other groups.

Age numbers overall

While we’re here, I want to point out something in the recent data. Obviously, the huge spike among high school and college-age individuals was the focus of a lot of attention over the past few weeks, and deservedly so.

But over the past few days, the spike in youths has died down just a little, while every other group has grown. The 15-24 age group is still seeing the biggest rate, but now most age demographics are facing their highest coronavirus prevalence of the pandemic.

This shouldn’t be any surprise — it’s exactly what most predicted two weeks ago. But it is notable because it refutes the argument of the small but vocal contingent who said the kids getting the virus wasn’t big deal because they’re not particularly high-risk of hospitalization or death. But that’s the thing: the virus can travel up the demographic spectrum too, and we’re seeing evidence of that.

Cases through social interactions

The dashboard also has an updated view from Utah contact tracers, who work to find where cases are coming from. In particular, they want to know if an infection came from a known contact. If an investigation is done and they can’t figure it out, they chalk it up to community spread (we don’t want to see this). And as you can see, the number of cases that have come from known contacts is falling, albeit not very quickly.

But when you break it down by those people who have a best guess as far as where their exposure came from, we’ve seen more significant change. Here, while household spread still rules, we’re seeing bigger upticks in social spread.

Again, that makes sense given the recent explosion in cases: household spread probably isn’t enough to explain cases going from a rough average of 500 per day to 1,000 per day in the course of a week, like we experienced in mid-September. But socially-spread cases are pretty much preventable, too. Remember, it’s not just about social distancing, it’s about avoiding closed indoor spaces.

Other notes

• The health department’s old map got some criticism for changing the color scale as new cases came in — in other words, as the coronavirus situation in Utah got worse, the map didn’t always reflect that. But the new map has a set scale that reflects new cases in each area over the past 14 days, giving a truer idea of the state of the state. Let’s just say right now that the darker shades of “very high rate” and “high rate” are dominating this color-coded map, particularly in urban areas.

• State officials added some new information with regards to the prevalence of various preexisting conditions, including how they interface with different demographic groups. That being said, on first glance, the new data doesn’t seem to reveal anything very notable compared to our earlier conceptions of how preexisting conditions impact COVID cases. People with breathing problems, high blood pressure and diabetes are still more likely to have problems.

• They added results of two different sources of mask information — one where state employees actually go into communities to see whether people are wearing masks, and another where people are asked over the phone about their mask wearing habits.

But the data is a little wonky. For example, the observes report that 73% of people wore a mask in outdoor public places one week, then report 9% of people wore a mask outdoors the next week. That big of a gap just isn’t reflective of reality, so it calls into question their data. And self-reported mask data is going to run into real questions about whether or not people are being honest about their own habits. That said, this shows that women are more likely to wear a mask than men. That sounds right, unfortunately. Come on men, it’s time to mask up.

Andy Larsen is a data columnist who is focusing on the coronavirus. He is also one of The Salt Lake Tribune’s Utah Jazz beat writers. You can reach him at alarsen@sltrib.com.