Arizona State University researchers in Tempe are looking for traces of COVID-19 in wastewater, which could serve as an early warning system of the virus’s spread in communities.

Tempe officials said more data on how widespread the virus is in the city could help staff better deploy protective equipment and other resources, access testing kits and better prepare first responders and health care workers to handle the outbreak, said Rosa Inchausti, director of Tempe’s Strategic Management and Diversity Office.

“Now we wake up and instead of checking the weather every day we look for two numbers, how many people are infected and how many people have died. But you don’t know anything about the people who are asymptomatic or who haven’t been tested,” Inchausti said. “That’s just not enough information for public officials to be making decisions.”

At least one Tempe resident has tested positive for the virus but it’s unclear how many others who may be asymptomatic or unable to get tested are infected and possibly unknowingly spreading the virus. The Cottages of Tempe, an apartment complex geared toward ASU students, informed residents in mid-March that one of its residents tested positive for the new coronavirus.

Researchers from University of Arizona are doing similar work and say they've detected traces of the virus in untreated wastewater samples taken in Tucson.

More than a dozen research groups around the world have begun analyzing wastewater for traces of the virus to see if they can determine the number of people infected in a community, according to science journal Nature.

Researchers in the Netherlands were able to detect the virus in a wastewater treatment facility in a city about 30 miles southeast of Amsterdam before coronavirus cases were reported there, according to a March 30 story by Bloomberg.

ASU study in the early stages

ASU researchers are in the early stages of determining at what levels, if any, SARS-CoV-2, the virus that causes the COVID-19 disease, can be detected in wastewater, said ASU Professor Rolf Halden.

Halden, the director of ASU’s Biodesign Center for Environmental Health Engineering, and his team, which studies sewage samples in cities across the globe, have been monitoring wastewater in 30 U.S. cities to detect other viruses to develop early warning systems for flu and other outbreaks.

The team has created a test to determine whether genetic material from the coronavirus can be detected in untreated sewage. Tests are being conducted to determine if the detection method works.

The team has successfully detected the virus that causes COVID-19 in swabs obtained from health care providers, he said.

If the testing method works, researchers will collect samples from different parts of the city’s sewer system and monitor for trends, such as whether the amount of the virus present in the wastewater increases or decreases.

The samples will represent large geographical areas and can’t be tied to a person, household or establishment. Anyone who uses a restroom in the city contributes to the sample.

“There’s no way of tracing information back from what we detect to an individual. That’s not our objective,” Halden said. “We just want to be on the lookout and let people know about the presence and its arrival in the community.”

The team already has everything set up to receive, process and analyze the data.

Genetic material from the virus has been detected in the feces of some infected patients but little is known about how much of the virus is shed in stool, how long it is shed and whether it can be transmitted from the feces of an infected person, according to the Centers for Disease Control and Prevention.

UA finds traces of virus in wastewater

UA researchers have already detected traces of the virus in untreated wastewater samples taken at the Pima County Wastewater Treatment Plant, said Ian Pepper, director of the schools' Water and Energy Sustainable Technology Center, which is conducting the study.

The virus has not been detected in treated wastewater, he said.

Pepper said his team is collecting weekly samples and trying to determine whether the discovery is a true reflection of the number of people in the community that are infected.

Over time, the concentration of the virus in the wastewater samples could help predict if the occurrence of the virus is staying the same, increasing or decreasing, he said.

Pepper said the team plans to continue collecting samples in Tucson and wants to expand the program nationwide. Researchers already are collecting samples from sewage systems in California, he said.

A larger sample pool will help the team determine if there is a correlation between the detection of the virus in wastewater and the number of cases in a community. It also could predict future rates of infection, whether interventions such as social distancing help and monitor for possible re-emergences of the virus, he said.

Additional data could help Tempeaccess resources, testing kits

Tempe and ASU have been working for nearly two years to study biomarkers in the city’s wastewater. They’ve monitored traces of opioids in untreated sewage to help first responders shape early intervention and education efforts in the city and for levels of stress hormones, such as cortisone and cortisol.

Researchers and the city were looking to pivot the program to study other biomarkers and the coronavirus pandemic presented an opportunity to expand the program and learn more about the virus, Inchausti said.

Inchausti said city staff could use the data to get more protective gear for first responders and testing kits at local hospitals and clinics if researchers can detect the presence of the virus in the city’s wastewater.

It could also detect where there might be a concentration of cases so that the city and health care providers can focus resources in that area, she said.

Additional data could help the city better target public education and prevention messages, said Tempe Fire-Medical Rescue chief Greg Ruiz.

“First responders and health care workers are working round the clock but they’re just reacting,” Inchausti said. “We’re trying to identify a way to be more proactive.”

Reach reporter Paulina Pineda at paulina.pineda@azcentral.com or 480-389-9637. Follow her on Twitter: @paulinapineda22.

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