NASHVILLE, Tenn. (WTVF) — According to the CDC, 93% of all active COVID-19 cases are from an incredibly infectious strain called the Delta Variant.
Have you ever wondered how the CDC determines that number?
Vanderbilt University Medical Center's Medical Infectious Disease Lab, and others like it across the country, conduct genetic testing on COVID-19 samples to determine those numbers.
"So it’s all about getting a large but focused snapshot across different demographic regions to determine what is actually prevalent around the country," said Dr. Jonathan Schmitz, Medical Director of the Medical Infectious Disease Lab at VUMC.
Most COVID-19 test swabs are just screened to see if the patient has the virus. But inside Vanderbilt's lab, hundreds of swabs a week are tested again, this time to look at the genetic makeup.
"We are sequencing several hundred de-identified strains every week," said Dr. Schmitz. "Just like every human has their own DNA sequence, every virus, in this case, it’s an RNA virus so it has its own RNA sequence."
Dr. Schmitz says it's not critical for individual patients to know if they have the delta variant because it won't impact their treatment, but when it comes to public health, it's a real game-changer.
"The fact that this is such a contagious strain of course is cause for concern and explains what’s going on, on the ground," he said.
Schmitz says variant data collected across the country allows public health and clinical studies to evolve along with the virus. "Unfortunately, evolution is what viruses do. Viruses evolve very very quickly," said Dr. Schmitz.
In addition to partner hospitals like Vanderbilt, several local and state laboratories also report their genetic findings to the CDC, which then study the statistics and release their report.