A 30% decline in coronavirus material in Twin Cities wastewater over the past week offers further hope of a mild spring with respect to the COVID-19 pandemic.
Average viral levels last week were at their lowest since mid-April 2022, according to Friday's report from the Metropolitan Wastewater Treatment Plant in St. Paul.
"These data are encouraging, indicating less virus is circulating in our community. But, as always, we'll have to wait to see if the downward trend is sustained going forward," said Steven Balogh, a principal research scientist at the plant.
Viral levels had been stuck in a moderate, persistent range in the Twin Cities since last November. The latest metro wastewater readings fall below that range, and match with other favorable pandemic indicators released Thursday by the Minnesota Department of Health.
COVID-19 hospitalizations in Minnesota have nearly cut in half this month — from 401 on March 1 to 205 on Tuesday. Only 16 patients hospitalized on Sunday needed intensive care, the lowest number since the end of Minnesota's first COVID-19 wave in summer 2020.
March has been a transitional point in the pandemic over the past two years. Viral levels bottomed out in March 2021, only to surprisingly surge in April in Minnesota because of an alpha coronavirus variant.
An omicron BA.2 variant caused a similar turnaround in viral levels last April, but severe COVID-19 outcomes such as hospitalizations and deaths did not increase as a result of that wave.
What's next following declines in coronavirus levels this March is unclear, though the federal government is planning to end its COVID-19 public health emergency declaration by May 11.
The rate of COVID-19 deaths in Minnesota slightly increased from five per day in the last week of February to seven per day in the first week of March. Minnesota's seniors remain at greatest risk, accounting for 83% of the state's total of 14,539 COVID-19 deaths but 93% of the 484 deaths in 2023.
Health officials urged people at elevated risk of severe COVID-19 to consider precautions, because the effectiveness of variant-specific vaccine boosters may have waned if they received them last fall. And while 94% of seniors have received some COVID-19 vaccine, only 63% are up to date with the latest boosters.
Federal health officials are considering whether to match recent guidance in Europe and Canada and recommend another round of boosters in high-risk individuals to restore immunity levels.
Wastewater monitoring has taken on added importance as Minnesota has closed free COVID-19 testing sites and encouraged people to use at-home tests that are not reported publicly. The Metropolitan Wastewater readings match with data from 40 statewide treatment plants that have mostly showed declining viral loads over the past two months.