Outbreak Outlook - National - March 25

Respiratory virus season calms down.

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Respiratory Diseases

ILI

Influenza-like illness (ILI) dropped again this week, with outpatient visits declining from 3.7% to 3.4%. The national baseline is 2.9%, so we likely have a couple weeks left. Around 1 in 3 specimens tested were influenza B, which has been pretty stable for the last few weeks. Flu B activity usually picks up in springtime.

By age: All age groups saw marked declines in activity this week. Around 9.4% of visits to the doctor in kids 0-4 were for cough and sore throat, which is down from this season’s high of 15.5%. The 5-24 age group declined to 5.7%, and the older age groups are at 3% or under.

By region: Most regions saw substantial declines in their ILI activity. The Midwest wins the award for most improved; activity fell from 4.2% to 3.6%. It is still the most affected region, though. The Western region saw a slight increase in ILI activity, but I expect that to be short lived.

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COVID-19

Covid-19 activity is looking quite good, with new weekly hospitalizations dropping to 3 per 100,000. We reached 2 per 100,000 over the summer, and I bet we will get there again soon. Wastewater concentration supports this forecast; concentration is low and declining in all four regions of the country.

The South is currently most affected, though activity is declining steadily in that region. The Midwest and Northeast are both in the 3 per 100,000 range and falling. The West is in the best shape at 2.5. Secondary metrics like emergency department visits and test positivity are also all pointing in the right direction.

I hope and expect we’ll see continued declines in the weeks ahead.

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Stomach Bugs

There was a slight decline this week in norovirus test positivity, from 12.8% to 12.1%. It’s possible we are at or near peak, which means there is plenty going around.

Norovirus causes the classic “stomach bug,” with vomiting and diarrhea that usually resolves in a couple of days. The biggest concern is preventing dehydration. This is especially important in children and older adults, who dehydrate quickly. I keep Pedialyte powder packets in the pantry, because they take up less space and have a longer shelf life than bottles of liquid rehydration products. Water, broth, popsicles, diluted juice, sports drinks, etc. are also good options. Don’t fall behind by waiting until dehydration sets in. Encourage frequent sips from the onset of illness.

More on preventing the stomach bug: Norovirus spreads very easily between people through the “fecal-oral” route. To stop it from spreading, wash your hands thoroughly after using the bathroom and before eating or preparing food. I also use hand sanitizer while I’m in public like after I use self-checkout at the grocery store or when I use public transportation, but you should know that hand sanitizer is not as effective against norovirus as hand washing. Be sure to wash your hands properly when you get home. Most importantly, stay home if you have vomiting or diarrhea. 

If someone in your household gets norovirus, you can reduce the chance it will spread by keeping them out of the kitchen and disinfecting contaminated (read: bathroom) and shared surfaces. Also regard laundry like bedsheets, clothes, and towels as contaminated. Use gloves when handling the items and wash them thoroughly with hot water on the longest cleaning cycle.

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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

• Trader Joe’s 50% Less Salt Roasted & Salted Whole Cashews (more info)

Previously reported:

• Multiple brands of cinnamon sold at discount stores, for lead contamination. The best resource I found to quickly survey affected products is here.

• Robitussin Honey CF Max cough syrup products (more info)

• Tons of different granola and oatmeal products from Quaker (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

• A recent study from the COVID Symptom Study Biobank in the United Kingdom (summarized here by CIDRAP) finds a potential link between generalized joint hypermobility (GJH) and an increased likelihood of developing long COVID. Individuals with GJH had approximately 30% higher odds of facing delayed or non-recovery, particularly prolonged fatigue. The study notes that certain clinical phenotypes of GJH like hypermobile Ehlers-Danlos syndrome may be at higher risk of chronic fatigue and dysautonomia.

• Avian influenza A(H5N1) continues to circulate widely around the globe The virus is primarily found in wild birds, but it spills over regularly into commercial flocks and mammals. Spring is usually peak season for this virus. Recent developments of this years-long epidemic include an expansion of the virus into Antarctica; the first case in a domestic ruminant (that means a U.S. goat); and an increase in egg prices.

• PBS is airing a four-part documentary on public health called the Invisible Shield, beginning on March 26. (I might be in the second episode on public health data!) The trailer is really impressive ⬇️. Let me know what you think, if you tune in.