The Investigators: Shelby County Health Department changes how it measures COVID-19 infection rates

The change reveals more hot spots than previously thought

The Investigators: Shelby County Health Department changes how it measures COVID-19 infection rates

MEMPHIS, Tenn. (WMC) - Health officials have changed the way they are tracking COVID-19 hot spots in Shelby County.

Restaurants and stores in Downtown and Midtown Memphis are seeing more customers as part of Phase 2 of Shelby County’s Back to Business Plan.

At the same time, the zip codes that include Beale Street, Overton Square and Cooper-Young are seeing more COVID-19 cases.

The data is part of a new map the Shelby County Health Department is releasing, which shows the number of COVID-19 cases per 100,000 people.

The Health Department previously used a map that showed the percentage of positive tests in each zip code.

In Thursday’s Shelby County COVID-19 press brief, The Investigators asked about the shift in focus.

“In order to really determine risk and who’s at risk, you have to look beyond just percentages and you have to ask of those cases, what is the rate,” said Shelby County Health Officer Dr. Bruce Randolph.

A rate is determined by comparing the number of COVID-19 cases to population. You can then compare areas with different size populations by multiplying by 100,000 people.

For example, Shelby County has 420 cases per 100,000 people while Tipton County has 661 cases per 100,000 people. Shelby County has more cases overall, but COVID-19 is more prevalent in Tipton.

“The rate gives a better indication of understanding of disparity and how much of a disproportionate effect the disease is having on a given population,” said Dr. Randolph.

In a separate statement, Shelby County’s Chief Epidemiologist added, "Both ways of looking at the data are valid. The use of rates just seemed more methodologically appropriate to us as testing became more readily available.”

The new map reveals that 38118 remains a hotspot.

Shelby County said a new hotspot in 38133 is the result of more testing in that area.

Health officials also attribute the hotspot in the Downtown-Midtown area to the more than 200 inmates and staff who tested positive for the disease at 201 Poplar, where the Shelby County Jail is located.

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