Alaska researchers try to anticipate COVID-19 spikes by testing waste

A grey blocky building with high windows and several pickup trucks out fronnt
At Sitka’s wastewater treatment plant, they’re testing the water weekly in an attempt to detect changes to the level of coronavirus present in the community (Katherine Rose/KCAW)

As Alaska experiences a new wave of the coronavirus, contact tracers are working around the clock to track exposure. But what if there were a faster way to predict when a wave would happen, before new COVID-19 cases started rolling in? Researchers at the University of Alaska are partnering with communities around the state to figure out if they can make haste by testing waste.

Sitka’s wastewater flows into a treatment plant on Japonski Island. And while it may not look pretty, what gets washed down the drain can provide clues about how Sitka is faring in the pandemic.

Sitka’s environmental superintendent Shilo Williams says a machine pulls a liter of water from the wastewater stream once a week.

“We collect it in a sample container, and we put it in a cooler and we ship it up to the lab,” she said.

That cooler is sent to Dr. Brandon Briggs’ office. He’s an associate professor who runs a research lab at the University of Alaska Anchorage.

“What we’re trying to do is find the viral particles that are within the waste water. So when somebody has been infected, we’ve found that some of that virus is actually shed into the wastewater,” he said. “So we can actually go through and start trying to detect that.”

Murky water runs throuogh a channel
2019 photo of raw wastewater flowing into Sitka’s treatment plant (Katherine Rose/KCAW)

His team is partnering with Dr. Eric Bortz, a virologist who has studied coronaviruses for over a decade.

Briggs says in May, the lab began collecting wastewater data from communities around the state, first focusing on Anchorage and Fairbanks. And what they found in the wastewater lined up with the number of cases being reported by the Alaska Department of Health and Social Services. When there were lulls or spikes on the state’s coronavirus dashboard, Briggs’ team saw the amount of viral particles in the wastewater change, too.

“We were actually able to track that within the wastewater. So the amount that was being tested with the clinical testing, we were able to track that quite well,” he said.

Briggs hopes they can use the information to help communities predict and prepare for new COVID-19 waves a couple of days before public health officials start seeing rising case counts.

“We should be able to see the virus within the wastewater a couple of days before usually somebody goes and gets clinically tested for it,” Briggs says.

But the method does have its limits. Briggs says how much of the virus a person sheds tends to change throughout the course of an infection, and one recent study showed some people may not shed the virus into wastewater at all. And there’s a threshold. There have to be a certain number of cases in a community before Briggs’ team will be able to detect the virus in their samples.

“There’s also dilution. So everybody is depositing into the sewer system, so to be able to detect that, it can’t be diluted that much,” he said. “So with the two or three cases we saw from Sitka, that seems to be below our detection limit.”

So far in Sitka, they haven’t seen any traces of the virus in the wastewater. Shilo Williams says two test results have come back so far. That checks out: While the rest of the state’s coronavirus infection rates have soared, Sitka’s rates have been low this October.

“There are labs across the country that are analyzing COVID-19 in wastewater, so it’s great that we’re able to keep it in state and have a good working relationship with the folks at UAA,” Williams said. “And I think it’s great that we can help researchers learn more about the virus by doing this study.”

Williams says they’ll continue testing for COVID-19 at Sitka’s wastewater treatment plant through the end of the year. The wastewater reports will be published weekly on the city’s COVID dashboard.