Tri-county hits its highest weekly COVID case rate since start of pandemic

The average number of COVID cases per day over the past week in the Charleston Tri-county area hit its highest level since the start of the pandemic — and it’s likely to keep rising for the next few weeks. That’s according to the leader of the Medical University of South Carolina’s COVID tracking team.

“It's definitely going up, increasing over the past week by 26%. There's a real outbreak going on.” said Michael Sweat, Ph.D., a public health expert and professor in the College of Medicine at MUSC, adjunct professor at the Bloomberg School of Public Health at Johns Hopkins University and former epidemiology researcher at the Centers for Disease Control and Prevention.

He said the new high, 81 cases per day for every 100,000 people in Berkeley, Charleston and Dorchester counties combined during the past 7 days, probably won’t be the end of the increase. 

 

“The pattern that we see all over is that it blows up, case numbers climb somewhere between 100 and 200 cases per day per 100,000 people. And then the case numbers rapidly start coming down again.”

The origin of the Tri-county area’s current surge can be traced to mid- to late-June, when the highly contagious Delta variant first showed up in testing at MUSC. It quickly became the dominant strain. Case numbers rose from almost nothing to the record-setting high of today.

Sweat predicts numbers in the Tri-county area will peak in September, then fall in October. “Up in Missouri, where it started, their case rate is now flat or going down in counties across the state. That tells you a lot,” Sweat said.

“It makes sense, because it's so transmissible that it just blows up. It rapidly goes through communities. And I think two things begin to happen. People become very aware of it and start masking and being cautious and not gathering indoors, and the virus also just kind of runs out of fuel. It infects so many people so rapidly that there aren't many people left to infect.”

That jibes with what researchers found in the U.K., where they estimate more than 90% of the population has antibodies to the virus. “So a lot of people are wondering, are they getting to herd immunity? Could that happen here? That was what was being talked about last week. But interestingly, this week, some scientists are saying don't get too excited because we're seeing a lot of breakthrough infections among vaccinated people that could be fueling further transmission,” Sweat said. 

“We’re definitely seeing waning immunity. But the vaccines still protect quite well against hospitalization and death. The advantages of getting vaccinated are enormous.”

Booster shots, reportedly coming in the near future, could bolster those advantages.

In the meantime, Sweat said that if numbers soar in the Tri-county area, it could put a lot of stress on hospitals. “You're getting lots of infections in young people. They don't get hospitalized as much. However, the Delta variant spreads so quickly that it can flood the hospitals with people.”

But he is hopeful about the near future. “Like other places we're going to go through a tough time, but it'll probably get better. And then a month and a half, you know, we'll be coming on that downslope."