Three red flags for Tri-county area as COVID cases increase, but 'it's not too late to act'

June 17, 2020
Graph showing an increase in estimated COVID-19 cases
This graph from the MUSC COVID-19 Epidemiology Intelligence project shows a dramatic increase in the estimated number of cases in the Tri-county area.

Three red lights are now flashing for the Charleston Tri-county area in the Medical University of South Carolina’s COVID-19 Epidemiology Intelligence Project. Michael Sweat, Ph.D., leads the MUSC team tracking the coronavirus in Berkeley, Charleston and Dorchester counties. It just released its weekly update.

“We have three key indicators in the red zone now. One, the growth rate of infections has surpassed 5%. It’s now 5.3%,” Sweat said. The previous week’s growth rate was 3.6%, which kept it in the yellow zone.

“Two, we’ve had two weeks of increases in the number of cases.” That indicator was already in the tracking project’s red zone in the previous update, so it stays there.

Dr. Michael Sweat 
Dr. Michael Sweat

“And three, we have an indicator that relates to the number of cases per population. So when you get more than five per every 10,000 residents in a week, that triggers a red. For our population size in Charleston, that five per 10,000 equals 388 cases in a week. We just had 589 cases in a week. So that went red as well.”

To put that in perspective, in the previous update, 292 cases were reported, qualifying for the yellow zone.

“People need to know that it’s growing all of a sudden, and quickly,” Sweat said. “Every percentage point increase just magnifies the challenge of getting it back down again.”

Sweat called the trends troubling, but pointed out the actual number of people with COVID in the Tri-county area is still manageable. There’s plenty of hospital space, and COVID-19 testing is widely available. “The number of active cases we have is something like 800 right now. That’s not a massive number for the size of the population. We have 780,000 people in the area. That’s important to keep in mind.”

Graph showing growth rate of COVID-19 cases is 5.3% as of June 17. 
The growth rate has surpassed 5%, putting it in the red zone.

But Sweat said now is the time to take the situation seriously. “It’s not too late to act. We’re not in a disaster. I don’t want people to overreact. But it is a signal for us to really get in line and start doing the mask thing.”

Recent history shows things can change quickly when it comes to the coronavirus. “When this all started in early March, I think it was March 6, there were 600 cases in the whole United States. It was just weeks before we reached tens of thousands, hundreds of thousands, and now we’re up to two million. It hasn’t been that long. So it can blow up rapidly,” Sweat said. “We have thousands of active cases in our state right now. If we backtrack on our distancing and mask wearing, it amplifies the potential for a blowout.”

If people in the Tri-county area increase social distancing and mask wearing in response to the new numbers, as Sweat hopes, the risk of a blowout goes down. “I think we’re in a strange space. It’s hard to predict what’s going to happen next. Ultimately, I think we’re going to see a sort of undulating pattern of up and down until a vaccine comes.”

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