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Researchers develop new tools to detect COVID variants in wastewater

Posted at 8:17 PM, Jul 07, 2022

SAN DIEGO (KGTV) — Scripps Research and UC San Diego have developed new tools that can detect COVID variants in wastewater days before clinical testing using a nasal swab.

Last year, UC San Diego began screening wastewater to predict COVID-19 caseloads in the community since people shed the virus in their stool before they start showing symptoms.

"This basically takes the next step beyond that," said Joshua Levy, PhD, with Scripps Research.

Levy said scientists can now identify specific variants present within a population and new variants of concern up to 14 days before clinical testing.

"About two weeks before Omicron had been detected clinically in San Diego, we were already seeing it in wastewater," he said.

Over the course of nearly a year, the group analyzed more than 20,000 wastewater samples.

The latest data shows Omicron subvariants as the dominant strains in San Diego County.

"Now, we're looking at this kind of growing amount of BA.4 and BA.5 lineages, which are rapidly sweeping through the population," Levy said.

The math and science behind the technique are pretty complex, but simply put, Levy said he developed a code that can pinpoint how much of each variant is present in a wastewater sample.

"Rather than having to take thousands of samples from individuals throughout the population, you can take one and get a sense of what's going on in the whole population," Levy said,

Researchers believe it's important for public health officials to track variants since they differ in how the virus spreads and infects people.

Levy said the new data could further help with the response.

"The project required a tight collaboration between hospitals, state and local governments, sequencing facilities, and academic scientists," the press release said.