The amount coronavirus detected in wastewater in the Twin Cities has reached a new pandemic high, which is indicative of the extremely high levels of the omicron variant circulating in the region.
Tracked regularly by the Metropolitan Council’s Environmental Services scientists, the amount of coronavirus (SARS-CoV-2) flowing into the Metro Plant can serve as a predictor for a rise or fall in infections, as new cases tend to lag wastewater detection trends by about 6-8 days.
The virus is tracked in wastewater by copies of viral RNA per milliliter. Through Jan. 6, the Met Council tracked 1,047 copies of RNA per milliliter, which is far and away the highest indicators of COVID-19 in wastewater in the two-plus years of the pandemic.
You can see the surge in the charge below, which shows a blue line to indicate SARS-CoV-2 in wastewater and a gray line, which reveals the 7-day rolling average for new cases per day in the seven-county metro.
Because wastewater serves as an accurate predictor for new infections in the community, the spike in the graph above preceded last week's surge in new cases.
And the surge in cases and wastewater indicators corresponds with the arrival of the omicron variant. The Met Council tracks which variants are flowing through sewage, and the chart shows omicron (green) spiking as it replaces the delta variant (blue) as the dominant strain. As of Jan. 8, omicron accounted for about 85% of all SARS-CoV-2 found in metro area wastewater.
The hope in the coming days is for SARS-CoV-2 wastewater levels to decrease, which could be an indicator of falling infections and perhaps. The omicron surges around the world have been rapid, with just-as-rapid decreases after the peak.
For example, in the Boston metro area, the viral load in wastewater skyrocketed around the holidays but has dropped 55% since Jan. 3, according to the Boston Herald. Health officials there are "cautiously optimistic" that they are headed for a sharp decline in cases, followed by a drop in hospitalizations a few weeks later.