As Alaska experiences a new wave of the coronavirus, contact tracers are working around the clock to track exposures from every case. But what if there was a faster way to predict when a wave was about to happen before the positive COVID-19 cases started rolling in? Researchers at the University of Alaska are partnering with communities around the state to figure out if we can make haste, by testing waste.
That’s Sitka’s wastewater (pictured above) flowing into the treatment plant on Japonski Island. And while it may not look all that pretty, what we wash down the drain can provide some clues to how Sitka is faring amid the COVID-19 pandemic.
Sitka’s environmental superintendent Shilo Williams says that once a week a machine pulls a liter of water from the wastewater stream.
“We collect it in a sample container, and we put it in a cooler and we ship it up to the lab.” she says.
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 says. “So we can actually go through and start trying to detect that.”
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 on the state’s coronavirus dashboard, Briggs team saw the amount of viral particles in the wastewater taper off too. And when they saw spikes…
“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 says.
Briggs hopes they can use the information to help communities predict and prepare for new COVID-19 waves, a couple of days before the hospitals 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 test 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 says. “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 says. “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. View current reports here.
