Risk assessment: New map attempts to show COVID-19 exposure risk

Chad Frey
cfrey@thekansan.com
A new interactive map created by Georgia Tech, released early Thursday morning, attempts to show how the size of a crowd affects COVID-19 exposure risk.

The Harvey County Commission rolled the county back to Phase III of its reopening plan this week, limiting crowd sizes to 45 or less in the county. McPherson County took similar action — moving their county to Phase II, limiting groups to 15 or less.

The idea behind such moves is that limiting group sizes limits individual exposure risk during a time when the health departments of both counties report being stretched thin — and area hospitals report running out of space to treat COVID-19 patients.

A new interactive map created by Georgia Tech, released early Thursday morning, attempts to show how the size of a crowd affects COVID-19 exposure risk — and that map contains county data for every county in the United States.

According to the map, in Harvey County if a crowd of 100 gathers there is a 99 percent chance that at least one person with COVID-19 will be in that group. The same is true for McPherson and Reno County. Sedgwick County the risk is 98 percent, while in Butler County the risk is 93 percent.

Move that crowd size to 50, more in line per the Harvey County order, and the risk in the county moves 92 percent. In McPherson County and Butler County the risk drops to 88 percent. Reno COunty hovered at 93 percent, Sedgwick County 94 percent.

Drop the crowd size to 15 to reflect the McPherson County restriction, and the risk drops to 53 percent in Harvey County, 47 percent in McPherson County, 32 percent in Butler County, 42 percent on Sedgwick County and 54 percent in Reno County.

“We really are at a point in this county where [The County Commission/Board of Heatlh} needs to make decisions to slow the spread,” said Lynette Reddington, director of the Harvey County Health Department. “ ... The suggestion is to look at the mass gathering limits.”

The map can be found at https://covid19risk.biosci.gatech.edu/. Due to intense web traffic, according to a twitter accout associted with the website, the map took several attempts to load Kansan reporters Thursday morning.

The crowd size restrictions have affected events — in Harvey County the change led to the cancellation of a Christmas event in downtown Newton planned by the Gathering Church in Newton.

The Kansas High School Activities Association Eight Player Football Championships — for both Division I and Division II — have also been caught in the crossfire of COVID-19.

Both games are scheduled to be played Nov. 28, and at this time scheduled to be played at Athletic Park. However, the Harvey County Commission/Board of Health may have tackled the games with moving the county back to Phase III of the COVID-19 reopening plan.

That plan limits mass gatherings to 45 people — even for outside events.

“That is something we will have to revisit, that did not pop into anyone’s mind,“ Westfall said.

He told The Kansan that the county action did not have any exemptions within it that would allow for the games to move forward.

And there are other events — like the Boys Scouts of America Trapper’s Rendezvous in January at West Park that have already met with the commission to discuss options for moving forward as a one day event with no camping. It is unknown how many people the event would draw. Traditionally a multi-day event with camping at West Park, the event would draw thousands of scouts and leaders.

A decision by the commission for that event was tabled at the Tuesday county commission meeting.

“I am sure we will hear from a number of events like that,” Westfall said.