The Spread Sheet

December 22, 2025

Respiratory virus season is underway. As we head into the last two weeks of the year, here is what you need to know about disease spread across the country…

Influenza is on the rise.

The level of influenza across the country is increasing, and the test positivity has increased to 14.8% (up from less than 8% last week). It is officially flu season.

There is still time to get your flu vaccine. Dr. Jerome Adams, who was the Surgeon General during President Trump’s first term, recently posted this on X —

Please get your vaccine.

COVID and RSV are also spreading (though not as rapidly as the flu). We are also seeing a lot of people with the common cold.

A lot of people are sick. As we head into the holidays, please remember —

✅ When we gather together in large groups to celebrate the holidays, there is a risk that we will share our germs (as well as our time together). To avoid sharing germs at your celebration, agree with your friends and family that individuals who are sick are not welcome at the table or at the parties. If someone is running a fever or has a sore throat, they should stay home, rest, and get better before celebrating.

Sick individuals stay home.

I know it sucks, especially if you are the one who has to stay home, but we all must agree that staying home while we are sick allows us to get better and protects others from getting sick.

Sick individuals stay home.

WastewaterSCAN is monitoring the amount of virus in the wastewater.

Wastewater can be used as a predictor of future disease spread. The amount of influenza virus in the wastewater is HIGH and increasing across the country. This is a sign that the number of influenza cases will continue to increase in the coming weeks. Our research group will be watching this closely…

In addition to tracking the respiratory viruses, our research group — the Phlegm Fatales — is also tracking norovirus (aka the stomach bug).

Norovirus is still spreading.

Wastewater levels are down, but it is not clear if this is a sign that norovirus is actually decreasing or if we are just seeing a momentary slowdown in the number of cases. This one-week dip in norovirus is NOT a clear indicator that the disease is decreasing. We will continue to watch the data…

To prevent the spread of norovirus, be sure to wash your hands, especially before you eat or prepare food. Washing your hands will also prevent the spread of hand, foot, and mouth disease — another virus spread through respiratory droplets.

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As always, if you have questions or need more specific information about disease spread or respiratory virus season, please reach out.

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Epi(demiology) Matters is written by Dr. Becky Dawson, PhD MPH — an epidemiologist, teacher, mom, wife, and dedicated yogi. She is a tenured professor at Allegheny College, Research Director at a community hospital, and an exclusive contributor (all things health & medicine) at Erie News Now (NBC/CBS). Her goal is to create healthy communities for all. She writes Epi Matters — first & foremost because epidemiology does matter (to all of us) and she hopes that each post will help to educate and empower readers to be healthy and create healthy communities.

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