COVID cases keep falling around Charlotte, but fewer people are getting tested

Coronavirus mutations have circulated in and around Charlotte for weeks — but just how many, and just how quickly, remains an unanswered question.

Local health leaders lack the infrastructure to sequence COVID-19 test samples, which would pinpoint the prevalence of more transmissible strains in Mecklenburg County, including the United Kingdom variant first detected here in January.

But there’s another hurdle: A steady drop in COVID-19 tests administered means there are fewer samples to be analyzed and less data for health experts to predict the pandemic’s upcoming trajectory.

”Part of our ability to detect the spread of the variants and understand what they mean relies on robust testing to occur,” Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health Security, told the Observer.

“In general, we’re at a point where there’s still enough community transmission that we want to encourage people, especially symptomatic people, to be tested.”

The average volume of daily tests administered among Mecklenburg residents fell below 3,100 last week, the most up-to-date data show. That’s an almost 16% decrease compared to the prior two weeks.

In early February, Mecklenburg was averaging more than 4,000 tests each day. And in the days leading up to Christmas, demand skyrocketed beyond 5,000 tests.

Mecklenburg Public Health Director Gibbie Harris has repeatedly urged residents to seek coronavirus tests, emphasizing options are free and widely available. Significantly lower demand, not limited capacity, is driving the decline in total tests run locally.

At the same time, the county has seen far fewer positive cases per day and the percent of positive tests has greatly improved since late February. Over the last five days, Mecklenburg’s positivity rate fell to 4.8%, Harris told county commissioners Tuesday.

“It has been quite some time since we were below 5%,” Harris said, emphasizing Mecklenburg is now in the yellow tier — the lowest classification — of the state’s county alert system. “Trends continue to move in the right direction.”

Improving metrics could mean Charlotte soon may not need large-scale testing sites throughout the community. But the region is not out of the woods just yet, said Dave Wessner, a coronavirus researcher and biology professor at Davidson College.

“The less testing we’re doing, we’re not catching the spread,” Wessner said. “If there’s any uptick in spread, we’re not going to be catching it as easily.”

The future of COVID tests

Adalja said widespread COVID-19 testing will taper off as more people get immunized against the virus, though hospitals are expected to routinely screen for the virus and other respiratory ailments. With vaccines not available to children for now, baseline testing may be needed at schools, as will probably testing at colleges and universities.

Mecklenburg’s stabilized positivity rate — even amid reduced testing where likely only sick individuals are seeking a diagnosis — underscores coronavirus conditions are improving locally, Adalja said.

If conditions were worsening, the positivity rate would rise to reflect greater virus spread. By contrast, if more testing occurred in Mecklenburg, the county could see a positivity rate landing further below the 5% threshold used by the World Health Organization and state health officials to partially guide reopening decisions.

People who are fully vaccinated do not need to get tested if they come into contact with an infected individual — unless they experience symptoms, according to new guidance issued Monday from the Centers for Disease Control and Prevention. Fully vaccinated people who live in a group setting, such as a detention center, should still quarantine for 14 days and get tested for the virus, regardless of symptoms, the CDC says.

It’s too early to know how effective the vaccines will be against the variants. Wessner said Mecklenburg can combat contagious spread once about one-third of the county’s population is vaccinated. The number is still far below the 65%-85% threshold experts believe is necessary to reach herd immunity, yet more community protection signals less opportunity for virus transmission.

As of Tuesday, 10.6% of adults in North Carolina have been fully inoculated, the state Department of Health and Human Services reported. In Mecklenburg, only 7.5% of the population is fully vaccinated. Those percentages do not account for vaccines administered in long-term care facilities, such as nursing homes.

Mecklenburg has logged 98,308 coronavirus cases since the start of the pandemic, DHHS reported Tuesday afternoon. County officials say 891 residents have died of coronavirus-related complications.

Vaccines by county

More than 2.9 million vaccine doses have been administered across the state, DHHS reported as of late Monday. About 17.4% of North Carolinians are at least partially vaccinated, and 10.6% are fully vaccinated.

Here’s how counties in the Charlotte area compare, as of late Monday.

Mecklenburg

People at least partially vaccinated: 133,442

People fully vaccinated: 83,327

Union

People at least partially vaccinated: 32,058

People fully vaccinated: 18,295

Gaston

People at least partially vaccinated: 30,961

People fully vaccinated: 18,790

Cabarrus

People at least partially vaccinated: 25,794

People fully vaccinated: 16,138

Iredell

People at least partially vaccinated: 25,959

People fully vaccinated: 15,787

Rowan

People at least partially vaccinated: 17,026

People fully vaccinated: 11,420

Cleveland

People at least partially vaccinated: 17,172

People fully vaccinated: 8,742

Lincoln

People at least partially vaccinated: 12,499

People fully vaccinated: 7,340

Stanly

People at least partially vaccinated: 8,953

People fully vaccinated: 4,699

This story was originally published March 9, 2021 at 3:45 PM.