Twin Cities area COVID-19 levels plummet in wastewater data

Coronavirus levels in Twin Cities-area wastewater have plummeted 69% in 10 weeks — a sign of tangible progress alongside the symbolic lifting of national and international pandemic emergency declarations.

The decline since mid-February occurred despite an increase in the latest viral levels found through sewage sampling at the Metropolitan Wastewater Treatment Plan in St. Paul. The one-week increase, reported Friday, was driven by an unusually high reading on one day.

Without that anomaly, levels would have declined another 10% over the past week, said Steve Balogh, a principal research scientist in charge of the Metro wastewater testing.

"The viral load entering the Metro Plant is as low as it has been in over a year," he said. "So, the near-term situation looks good ... We're heading into warmer weather and the school break, which should mean fewer virus-spreading opportunities."

Spring was low tide for COVID-19 before increases in cases, hospitalizations and deaths in the past two years, but all signs in 2023 point to a sustained decline or even end to the pandemic threat. The 164 COVID-19 hospitalizations in Minnesota on Monday were the lowest total since summer 2021, and included only 16 patients requiring intensive care, according to Thursday's weekly state report.

Minnesota continues to report about four COVID-19 deaths per day, mostly in seniors, but that is down from nine or 10 per day in early January. And while the data is preliminary, April 9 appears to have been Minnesota's first day of zero COVID-19 deaths since last June.

The World Health Organization on Friday lifted its emergency declaration, even though the SARS-CoV-2 coronavirus is still a pandemic threat causing infections worldwide. The announcement preceded the scheduled end of the U.S. public health emergency on May 11, which among other things will result in reduced federal reporting of pandemic trends.

COVID-19 hospitalizations will become the primary indicator of county-level pandemic concerns, as the Centers for Disease Control and Prevention will phase out its community-level risk designations.

COVID-19 case rates and test positivity levels have shown to be a couple of days faster in detecting changes in pandemic trends compared to hospitalizations, according to a federal analysis. But COVID-19 hospital admissions proved reliable at identifying changes in pandemic threats at the local level.

Studies have found that wastewater sampling predicted changes in pandemic activity faster than all other efforts. Surveillance will continue for now at the Metro site and at plants statewide that feed their results to the University of Minnesota. Viral levels have declined statewide as well, according to the latest results.

The Minnesota Department of Health will continue its weekly updates of COVID-19 levels. That includes its breakthrough analysis of COVID-19 cases by vaccination status, which was updated Thursday to compare infections, hospitalizations and deaths by whether people had received the latest bivalent booster doses.

Prior comparisons were limited because immunity had waned in people who had received their initial shots or older boosters months or years earlier.

The latest analysis showed little difference in COVID-19 death rates over the past six months among non-elderly adults. However, the rate of COVID-19 deaths in unvaccinated seniors was 1.9 times higher than it was in seniors who had received the initial vaccine series and 5.5 times higher than it was for seniors who had received the bivalent boosters.