Pima County wastewater shows COVID-19 variants

Pima County wastewater shows COVID-19 variants

TUCSON, Ariz. (KOLD News 13) -Wastewater epidemiology is an integral part of tracking the prevalence of COVID-19 in Pima County and the University of Arizona campus.

Dr. Ian Pepper, director of the WEST Center and a University of Arizona environmental science professor, and his team have only been able to test for variants for a few weeks, and the technology to do so is still developing.

They test water coming through the Agua Nueva water reclamation — one of two major facilities handling sewage from the Tucson metropolitan area. COVID-19 samples in the wastewater can show a positive result often several days before the onset of symptoms in people.

Now, the same technology is showing a rise and prevalence of COVID-19 variants around Arizona.

Pepper said his team found both the UK and the Brazilian variant through their testing at Agua Nueva. The problem is, once these variants, especially the UK strain, are found in a community, it doesn’t take long for it to spread.

“Once it’s there, it quickly becomes the dominate strain,” Pepper said.

Pepper’s team first found the UK variant on March 10, and only seven days later, he said they pinged the Brazilian variant in Yuma, where they’re also testing wastewater.

“Given the concentrations that we’re seeing, I don’t think it’s been in the community too long,” Pepper said.

There are likely more variants floating around, but the tests just have not been able to prove their existence here. However, Pepper said that, while the variants are concerning to see, wastewater testing shows the original genome of the COVID-19 virus is increasing, too.

Concentrations of the virus in wastewater have followed what happens in the community. Pepper said, like clockwork, the increase in concentrations happens about a week after restrictions are lifted or a holiday, the opposite is true when mitigation measures are put into place.

Pepper said he and his team hope to test more consistently for the various strains in the community and on the university campus.

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