The coronavirus load in Twin Cities wastewater more than doubled over the past week, indicating a rising spread of COVID-19 in Minnesota.
The increase reported Friday by the Metropolitan Council was influenced by a one-day spike on April 17, when the viral load surged to the highest level since January's severe omicron COVID-19 wave. However, the viral load in samples from the St. Paul treatment plant rose steadily on other days last week as well, and the uptick matches recent increases in COVID-19 cases and hospitalizations.
The Minnesota Department of Health on Friday reported another 1,464 coronavirus infections, excluding infections identified by at-home antigen tests that aren't publicly reported. The seven-day average of new infections was 398 per day on April 1, but it increased to 827 on Tuesday. COVID-19 hospitalizations in Minnesota rose from 183 on April 10 to 234 on Thursday.
The rising totals remain far below pandemic peaks — with new cases exceeding 13,000 per day in mid-January and hospitalizations reaching 1,629 on Jan. 14. State Health Commissioner Jan Malcolm said she is encouraged that the latest growth in infections and viral load in wastewater hasn't been worse, or pressured hospitals.
"If you're only looking at percentage increases, it looks like, 'Oh my gosh!'" Malcolm said, "but the actual viral load is such a small proportion of what it was at the height" of the omicron wave.
Only 24 of the COVID-19 hospitalizations on Thursday involved people placed in intensive care. That represents 10% of COVID-19 hospitalizations, the lowest rate in the pandemic. The falling ICU usage rate suggests the current virus might be milder, treatments are improving or that recent infections and vaccinations have left many Minnesotans with immunity against severe illness.
"A case is not a case in the same way, perhaps, in terms of the impact on health and the disruption and pressures on the health care system," Malcolm said.
A review of blood drawn for various medical tests in January found that more than 48% showed the presence of coronavirus antibodies following infections. The Centers for Disease Control and Prevention consequently estimated that nearly 2.7 million Minnesotans already had been infected by then — compared with the 1.4 million that have been identified by reportable COVID-19 tests.