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4 min read National Report

Flu season gains momentum

Flu activity is increasing nationwide. Covid-19 activity remains low and mostly stable.

Flu season gains momentum

Respiratory Diseases

Influenza-like illness

Flu activity is low but increasing nationally. Visits to the doctor for fever and cough or throat (known as outpatient influenza-like illness (ILI)) is at 2.9%, which is right on the cusp of the 3.1% threshold for the start of flu season. Given that data is reported on a one-week lag, we may have already crossed into flu season by the time you’re reading this.

To give you a sense of where we are relative to peak season, last year outpatient ILI topped out at 7.8% and ED visits hit 8.4% nationally. Peak week generally hits around the New Year, though it can be earlier or later by up a month or more.

Test positivity is also continuing to rise, now at 7.1%, up from 4.6% the week before. Of the flu samples with subtyping performed, the vast majority of samples (>80%) are H3N2, and half of those are subtype K. As I’ve been reporting for several weeks now, this pattern suggests we may have a bigger-than-usual flu season.

Hospitalizations for flu are low but increasing, now at 1.2 hospitalizations per 100,000 people. Visits to the emergency department for influenza are also rising with alacrity in all regions.

At the state level, outpatient ILI is now high in several states: Colorado, New York, and Louisiana, and has moved into the moderate category in Idaho and New Jersey. It remains low or minimal in all other states. For more state-level information, please see the regional editions available to paid subscribers.

Rates have increased particularly sharply for children. The proportion of outpatient visits for ILI for children aged 0-4 years is now 9.3% of all outpatient visits. For those aged 5-24, it is 5.2%. Rates are between 1.2-2.2% for all older age groups.


COVID-19

Covid-19 held steady at low levels this past week nationally. However, at the regional level, I am seeing different trajectories, with wastewater concentrations rates rising in the Midwest, decreasing slightly in the Northeast, and still very low and stable in the South and West.

Emergency department visits for Covid-19 are at 0.4%. This is quite low, but there are signs of increases, particularly in the Midwest and Northeast. Hospitalizations are low and stable at 1.0 hospitalization per 100,000 people.


RSV & Other Bugs


Norovirus

Norovirus is quite active. Test positivity nationally was at 11.6% this past week, roughly on par with the week before. This is the time of year when norovirus is expected to just keep rising. To avoid infection, wash your hands frequently with soap and water (hand sanitizer is not particularly effective at killing norovirus) and avoid touching your face.


Food recalls

The following foods are being recalled because they are contaminated. Please check your cupboards and throw out any of these items:

New:

Previously Reported:


In other news


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Fall of the Cowboy (1895) by Frederick Remington. From the Carter Museum.