Vermont is changing how it tracks Covid-19 in the state’s wastewater

Experts believe the new system will provide a clearer picture of Covid and leave the door open for more disease tracking

By Erin Petenko/VTDigger

Bob Fischer, water quality superintendent for South Burlington, remembers when researchers first realized that they could track the health of a population through its sewer system decades ago. 

Measuring all the molecules and organisms that can show up in wastewater requires techniques and tools that started to be developed in the 1980s and 1990s. 

Back then, public health officials discussed using it to track drug use at a citywide level. Fischer noticed then that the levels of one substance in particular — caffeine — would go up in the bay whenever University of Vermont students would come back for a semester, and that still happens.

“The fish are probably jonesing when the holiday breaks come,” he said. 

More recently, wastewater surveillance has become one of the most promising ways to track diseases like Covid-19 by measuring the prevalence of signs left by the virus in a community’s sewer system. 

Experts have said that what we all flush down the drain can offer a more comprehensive picture of what is circulating than individual testing results — most Covid testing today are of the rapid in-home variety that are not regularly reported. Wastewater testing also provides an earlier warning sign than a metric such as the number of people hospitalized with a virus. 

However, since the Vermont Dept. of Health began including wastewater information in its weekly Covid reports in 2022, the tracking effort has been plagued with missing data and confusing or contradictory indicators. 

State officials hope a new company on the scene can resolve some of the ongoing issues. 

Three wastewater systems in Vermont — South Burlington, Essex Junction and Montpelier — are now sending water samples to WastewaterSCAN, a research program run by scientists at Stanford University and Emory University. The program has partnered with Verily, a health technology company owned by Google-parent company Alphabet Inc., which recently won a contract to support the U.S. Centers for Disease Control and Prevention’s national wastewater surveillance system.

Lynn Blevins, an epidemiologist for the health department, is hopeful that the new data and a new way of displaying that data provided by the new contractor will provide a clearer view of how Covid is spreading in Vermont. 

“We felt like people would be more informed by this graph than the prior table, especially going into respiratory season (and) going into holiday seasons,” she said.

The weeks after Thanksgiving, Christmas and New Year’s historically have been the toughest time for Covid in Vermont. The disease hit its peak in January 2022, when the first Omicron strain spread rapidly and strained hospitals and health care providers.

The health department reported on Wednesday that Covid levels remain “low,” based on their criteria of hospital admissions for the disease. The department said that 47 people had been newly admitted to hospitals for Covid in the past week, up from 36 the week before. 

That’s far from the peak of more than 20 admissions each day during the Omicron wave.  Blevins characterized Covid in Vermont as “pretty good” for winter. 

Like hospitalizations, data from WastewaterSCAN also indicates that Covid levels are slowly rising. WastewaterSCAN data is only available for the three sites (down from the 11 or so sites that have at times reported wastewater data to the CDC),focusing efforts only on cities with a population of 10,000 or more.