This week in outbreaks: Aug 18 edition

RSV begins to stir

Covid-19 activity continues to increase, according to both wastewater data and hospitalization metrics. Wastewater concentration rose in the Northeast, South, and West, per data from Biobot. In the Midwest, wastewater concentration fell after rising sharply the week prior. This does not necessarily represent a drop in SARS-CoV-2 activity. It’s possible that the last report was overestimated, or this week is underestimated. This happens sometimes, and it’s often corrected as more data becomes available. In any case, the overall picture is the same: Covid-19 activity is picking up.

Wastewater concentration of SARS-CoV-2. Source.

Hospitalization data tells the same story. Nationwide, the number of weekly hospital admissions rose again this week, as did the percentage of ER visits that resulted in a Covid-19 diagnosis. I see these increases in every region of the country. Florida and Hawaii are especially affected, as they have the highest rates of hospitalization. However, those rates of hospitalization are still well below historical highs.

What to expect next for Covid-19: Summer wave is a bit of a misnomer. In past years, Covid-19 activity has risen in the summer and then remained elevated through January. Activity sometimes dips modestly in the fall, but the “season” can effectively last from August to February. We will need to wait a few more years to get a clearer sense of the seasonal dynamics, but this is what I’m seeing for now.

RSV begins to stir: Last week, I said that we should have some time before RSV kicks up. I may have spoken too soon. For most of the country, RSV activity remains very low, but for certain states like Florida and Georgia, both wastewater concentration and PCR test positivity have begun to increase. To be clear, the number of reported cases is still quite low even in those states. But trends are headed in the wrong direction, so I plan to keep a close eye on RSV data in the coming weeks. (See also my post from a few weeks back, in which I made a few guesses about the upcoming winter season.)

RSV activity: PCR tests run (yellow) and test positivity (red) in Florida. Source.

The United States does not have great data on group A strep activity, so I look to the UK for clues. Rates of scarlet fever, one type of group A strep infection, have remained low there during the summer months. Last winter was an exceptionally high year for invasive strep. For reference, activity began to pick up in earnest in October.

Influenza activity is still minimal.

Food recalls (and dehumidifiers)

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

• I don’t usually cover consumer products, but a huge recall of 1.56 million dehumidifiers caught my eye. Dozens of models sold by major retailers, including Home Depot, Lowe’s, and Walmart, have been recalled because they pose a fire hazard. The recalled units were manufactured between 2011 and 2014 (more info — check this list carefully, it’s extensive)

• Soft Serve on the Go ice cream cups (more info)

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

In other news

• Florida has recorded eleven cases of locally-acquired dengue, two in Broward County and nine in Miami-Dade County. Several hundred cases of dengue are diagnosed in the United States each year (513 so far in 2023), but nearly all are diagnosed in returned travelers who got infected while abroad. Locally-acquired dengue is rare in the United States.

• In case you missed it, Your Local Epidemiologist and I published a guide to the fall vaccine options earlier this week. I hope it’s helpful as you look ahead to the coming months.