Here are the latest national COVID-19 trends, according to the U.S. Centers for Disease Control and Prevention (CDC) and major wastewater surveillance providers:
- About 0.8 in every 100,000 people were hospitalized for COVID-19 during the week ending December 6.
- COVID-19 test positivity moderately increased, from 3.5% of COVID-19 tests returning positive results during the week ending December 6 to 3.8% positive during the week ending December 13.
- SARS-CoV-2 concentration in wastewater increased 2% between December 6 and December 13, and the national wastewater viral activity level is “low,” per the CDC.
- SARS-CoV-2 concentration in wastewater increased 26% between December 3 and December 10, and the national wastewater trend is “medium,” per WastewaterSCAN.
- Healthcare visits for influenza-like illness increased 25% between the week ending December 6 and the week ending December 13, and this metric has passed the level indicating the official start of flu season.
COVID-19 spread continues to increase across the U.S. as we head into the most travel-and-gathering-heavy part of the year. Flu levels are also going up, more aggressively than COVID-19. The holidays often come with delays in infectious disease data updates, so keep in mind that COVID-19, as well as flu and other pathogens, may be more prevalent in your region than the most recent numbers suggest.
Wastewater data from the CDC and WastewaterSCAN show that the Midwest and Northeast remain COVID-19 hotspots as of mid-December, while disease levels are relatively lower in the West and South. WWSCAN reports a significant increase in its national average. Biobot Analytics hasn’t posted an update for this week.
The CDC’s wastewater viral activity levels have fluctuated dramatically in recent weeks. The agency reported a slight decrease in its national average of SARS-CoV-2 levels in sewage between November 22 and November 29, then a nearly 50% increase between November 29 and December 6, then a very slight increase between December 6 and 13, along with declines in regional averages for the West, South, and Northeast that week.
I suspect this fluctuation may be reflecting issues with data reporting rather than actual trends in disease spread. In particular, I’ve been keeping an eye on New York State, where the vast majority of wastewater testing sites have not reported data to the CDC in December. The state’s average wastewater viral activity level, as reported on the CDC dashboard, fluctuates in a similar way to the Northeast regional average, likely because it’s being driven by a small number of sites. Reporting delays and other issues may continue in the next couple of weeks as health officials take time off for the holidays.
Meanwhile, the CDC healthcare system metrics — which tend to be more reliable than its wastewater surveillance metrics — are clearer in reporting slow but steady increases in COVID-19 spread. Test positivity and emergency department visits are both trending up nationally and across different regions.
The CDC’s disease forecasting center, which uses emergency department visits to forecast trends, estimates that COVID-19 cases are “growing or likely growing” in 31 states as of December 16, including those across all regions except the Mountain West area, and only “declining or likely declining” in one state — Hawaii.
Flu spread also continues to increase, with flu leading to far more emergency department visits and positive lab tests than COVID-19 in the U.S. as of mid-December. The CDC’s forecasting center estimates that flu cases are growing in 47 states as of December 16. Influenza-like illness (a metric representing doctors’ visits for fever, cough, and sore throat) is increasing rapidly and already at “high” or “very high” levels in some states, including New York, New Jersey, Louisiana, and Colorado.
Virologist Angela Rasmussen has written a helpful explainer about the flu season so far in her newsletter, covering both Canada and the U.S. This year’s flu vaccines are not well-matched with the widely circulating flu variant, but vaccinations are still helpful for reducing risk of severe symptoms, she explains. She also notes that the “CDC’s ability to carry out core activities for managing flu season is hindered or completely impaired,” thanks to the Trump administration.
This will be the last COVID-19 trends update of the year, as The Sick Times is off next week. I wish you and your loved ones a safe and restful holiday season.
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[…] seeing increases. Notably, the CDC’s wastewater data have continued the fluctuating pattern that I flagged in December: alternating between stark increases and smaller ones. I suspect this is due to reporting […]