RALEIGH, N.C. (WNCN) — More than a dozen ZIP codes across North Carolina have shown the largest increases in new lab-confirmed COVID-19 cases over the past two weeks.
Modelers from the University of North Carolina and North Carolina State University who publish projections about the spread of COVID-19 this week began tracking how quickly the disease is spreading in each of the state’s roughly 1,100 ZIP codes.
They calculate the number of new cases each day in each ZIP code and plot them on a color-coded map according to the 14-day average of new cases per 1,000 people.
Paul Delamater, a professor at UNC who studies population health issues and infectious diseases, told CBS 17 News that this is not a “risk map” but rather a tool to measure how the numbers are changing over time.
“This is about change,” he said. “This is about where cases are changing. We may have places that are decreasing … that still have a high amount of cases. It’s just that maybe it went from 30 down to 25 down to 20 down to 15. And there could be places that show up red or high increases right now that actually don’t have a lot of transmission going on. It’s just that it is increasing over the time period.”
None of the ZIP codes in the CBS 17 viewing area were in the red zone on Tuesday — termed a “rapid” increase of at least three daily cases per week per 1,000 people — with many of them in the Piedmont Triad near Winston-Salem and Burlington, or in the Greenville area.
But ZIP codes in Fayetteville, Cary, Holly Springs and Hope Mills are among the localities color-coded in orange, which indicates moderate increases of 1-2 daily per capita cases per week.
Much of the map is colored yellow, meaning the case counts have been relatively stable.
One trend that became apparent to Delamater: ZIP codes colored in red are frequently located near orange ones, further illustrating the clustering tendency of COVID-19.
“That’s why you see a lot of yellow in the map — because a lot of places are either just level right now, or it’s kind of bouncing around and there’s nothing we can find in there,” he said.
Delamater called it a subjective decision to make three daily cases per week the cutoff between rapid and moderate increases, saying he “was just thinking about what would get me a little nervous as far as seeing a trend.
“It just seemed to me those are the places that show this strong upward trend, and the orange was just a little less,” he added.