Outbreak Outlook - National - December 18

Influenza-like illness and Covid-19 are increasing. RSV not looking as good as I had hoped.

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Respiratory diseases

Influenza-like illness

Influenza-like illness rose again, with 4.4% of visits to the doctor were for fever and cough or sore throat during the week ending December 9. The week prior was 4.1%. We have now been above baseline for 6 weeks. Flu season can last several months, so no surprise that we’re still seeing increases. 

By region: Five states are now in the “very high” category, including Louisiana and South Carolina. Other heavily affected states are concentrated primarily in the South, although NYC, New Jersey, and some Western locations are also rating as high. The Midwest remains most lightly affected, though I expect that will change over the coming weeks.

By age: Little kids are still battling the most ILI symptoms. 11.7% of visits to the doctor in the 0-4 age group were for ILI. For comparison, the peak last season was 17%. The 5-24 age group also saw a big jump this week, rising from 5.7% to 6.8%.

By severity: In last week’s email, I incorrectly stated that there had been no pediatric deaths so far this year. There have been 14. I misread the chart’s x-axis, not realizing that it extends months into the future.

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Covid-19

The number of new weekly hospitalizations increased slightly this week to 23,432, up from 22,730 the week prior. This is consistent with the idea that we are in the winter “wave,” though I continue to think this wave will be on the smaller side.

Wastewater concentration is also increasing, particularly in the Midwest. Wastewater concentration is actually higher there than it was last winter, which may challenge my hypothesis that this winter’s wave will be smaller than last year’s. Seeing what plays out will help me to understand how to interpret wastewater trends going forward.

Last week, some commenters asked if hospitalizations can be interpreted the same way this year as they have in years past. In other words, are the numbers comparable? It’s hard to say for sure, but I do think it is possible that the answer is no, hospitalization numbers are not comparable year over year. But there is a complementary data source, Covid-Net, that takes a different, more stable approach to understanding Covid-19 hospitalizations. That source agrees that hospitalization rates are lower than we’ve seen in any previous winter season.

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RSV

Hmm, my hopes that RSV season has peaked at the National level were dashed in this week’s data update. PCR test positivity increased to 12.3%, which is similar to recent levels. I’ll be keeping a close eye on next week’s data to get a better sense of which direction we are headed in.

I’m maintaining some degree of optimism though given that test positivity in the Southern region fell from 17.2% to 15.3%. It was above 20% just a few weeks ago, so that region is still heading in the right direction. I hope/suspect the other regions will follow sooner rather than later.

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Others

I’m monitoring several other respiratory viruses. 

• The seasonal coronaviruses, a cause of the common cold, are rising. Another cause of stuffy noses in the mix!

• Not much going on with human metapneumovirus. 

I’m seeing mixed signals for parainfluenza and adenovirus. CDC data has both at low levels, but Biofire data is showing some increases for both. Unclear.

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Stomach Bugs (Norovirus)

Norovirus activity is medium-high and rising slowly in most of the country, with the possible exception of the Midwest, where things may finally be cooling off. At the national level, current test positivity is around 10%, which is where it’s hung out for a few weeks. Keep washing those hands!

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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 this week:

• Tons of different granola and oatmeal products from Quaker (more info).

Previously reported:

• Ready-to-eat chicken breast products under Chef’s Line brand name (more info). 

• Ready-to-eat chicken fried rice under Freshness Guaranteed brand name (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 FDA is investigating a series of lead poisoning incidents in U.S. children, linked to three brands of cinnamon applesauce pouches: WanaBana apple cinnamon fruit puree pouches, Schnucks-brand cinnamon-flavored applesauce pouches and variety pack, and Weis-brand cinnamon applesauce pouches. Dozens of children under six years old have tested positive for lead poisoning from these pouches, with some showing lead levels over 500 times the acceptable threshold. The FDA’s Deputy Commissioner for Human Foods, Jim Jones, said recently that the contamination may have been intentional and is believed to be economically motivated. The investigation traced the lead contamination to cinnamon supplied by Negasmart to Austrofoods in Ecuador.

• Last week I reported on an increase of pertussis, a bacterial infection that causes a severe and sometimes deadly cough. I wanted to add (prompted by a helpful reader note) that pregnant women should receive a Tdap vaccine so that antibodies can transfer to the baby, providing some early protection. In addition to maternal vaccination, “cocooning,” or having other family members and caregivers get boosted, can also help to protect newborns from encountering pertussis. This should be repeated each pregnancy, because protection does wane.

• I’ll be off next week, but I’ll send out a quick note if anything important happens. Happy Holidays to all!

Photo by Tessa Rampersad on Unsplash