Outbreak Outlook - National - Feb 24

Respiratory Diseases

Influenza-like illness

Finally, a reprieve. Influenza activity dropped, bringing welcome relief from what has been a long and intense season.

Outpatient influenza-like illness (ILI), or the percentage of visits to the doctor that are for fever and either cough or sore throat, fell from 7.8% to 6.8% during the week ending February 15.

This level of activity is still quite high—exceeding most previous season’s highs—but at least we are heading in the right direction.

Improvements were seen across all age groups, with outpatient ILI in young children falling from 18.1% to 16.6%. Again, quite high, but improving. School age children saw almost a 1 point improvement to 11.4%. The older age groups were mostly stable; their trends are often delayed compared to the younger age groups, so I expect to see improvements in those groups in the weeks ahead.

Even more promising, the rates of hospitalization for influenza have fallen markedly in every region of the country. The Northeast saw a big improvement, though it remains the most heavily affected region. Hospitalization rates in the much-beleaguered South and Midwestern regions also dropped precipitously.

I do believe we may finally have turned the corner!

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COVID-19

The picture for Covid-19 is still quite mixed nationally right now. Some states are experiencing very high activity (like Kentucky and Arizona), while others have passed their winter peaks and are now settling down to quite low activity (like in Missouri). The wastewater national average declined slightly this past week, to moderate levels. Activity remains highest in the Midwest.

Emergency department visits for Covid-19 held roughly steady at 0.9% of all ED visits. Rates are substantially lower than they were last winter and during this year’s late summer wave.

Hospitalizations decreased a bit, down to a fairly low 3.2 hospitalizations per 100,000 people. The Northeast has the highest rates of hospitalization, but declines were seen there and across the board.

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RSV & Other Bugs

RSV activity continues to drift down as we head further out of peak season. Visits to the emergency department for RSV fell across all four regions of the country. All regions are reporting that less than 1% of ED visits are for RSV.

A few common causes of colds are at or nearing their high points for the season.

Human coronaviruses look to be nearing a peak, roughly consistent with peaks the past several years tending to fall in February-March. Human metapneumovirus also is at its highest point so far this season.

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Norovirus

Norovirus remains extremely high right now, with 22.2% test positivity. After a couple weeks of slight decreases in rates, rates crept back up a bit last week. Rates are very high in all regions of the country, with the highest rates in the Midwest.

Unfortunately, I do not expect rates to drop to low or minimal levels for a while still. Even in a normal year, norovirus rates tend to stay elevated throughout the winter months and into early spring. We are likely to see a similar pattern this year (just at higher levels of test positivity).

Source: CDC

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Food recalls

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

New:

• Nothing new this week

Previously reported:

• Menma Ajitsuke Prepared Bamboo Shoots sold under Choshiya brand name (more info)

• Canned Tuna sold under Genova, Van Camp’s, H-E-B, and Trader Joe’s brand names (more info)

• Alfalfa sprouts sold under the Jack and the Green Sprouts brand name (more info)

• Aleppo Tahini Sesame Paste (more info)

• DJ's Boudain sausage links (more info)

• If you have food allergies, you may wish to review these FDA safety alerts and USDA alerts for foods with undeclared allergens.

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In other news

• The USDA has reported bird flu (H5N1) in dairy cattle in Arizona, discovered through milk testing on February 13, 2025. This is the third time this type of bird flu has spilled over from wild birds to dairy cows, suggesting that spillover events are not as rare as once believed.

• Recent changes to Federal public health have prompted continued concerns about political interference in public health programs. The CDC has stopped its “Wild to mild” flu vaccination campaign. Also, the Advisory Committee on Immunization Practices (ACIP) has postponed its scheduled February 26-28 meeting, with no new date announced. The Infectious Diseases Society of America condemned the move in a recent statement.

• A new publication in the Morbidity and Mortality Weekly Report describes how two indoor house cats in Michigan died from H5N1 bird flu in May 2024 after their owners, who worked with dairy cattle, likely brought the virus home on contaminated clothing or equipment from farms with infected cows. The epidemiological investigation revealed that the cat owners worked at or transported milk from dairy farms known to have H5N1-positive cattle. One notable finding was that one of the cats would roll in its owner's work clothes, which were contaminated with unpasteurized milk.

• A large measles outbreak is unfolding in the Texas-New Mexico border region, with 99 total cases reported so far (90 in Texas and 9 in New Mexico). The outbreak is primarily affecting Gaines County, Texas, where 85% of the cases are children and only five of the infected individuals were vaccinated. Gaines County has one of Texas's highest vaccine exemption rates at 13%, with a kindergarten MMR vaccination rate of just 82%, which is below the CDC's recommended 95% threshold for community protection.

Photo by Dan Loftus on Unsplash