Flu, RSV, and Beyond: What’s Circulating Now and What to Expect
The landscape of infectious diseases is constantly shifting. As we move further into March 2026, data indicates a welcome easing of some respiratory illnesses, but vigilance remains crucial. Here’s a breakdown of what’s happening with flu, RSV, and other circulating bugs, plus a look at emerging threats.
Flu Season’s Slow Decline
After a challenging season, influenza activity appears to be decreasing across most of the United States. Outpatient visits for influenza-like illness (ILI) have dropped to 3.8%, with the Northeast experiencing the lowest rates at around 3%. Whereas older age groups are seeing smaller declines, rates have dropped more noticeably for children and young adults aged 0-24.
Emergency department (ED) visits for flu have likewise decreased, moving from 3.6% to 2.5%. Hospitalizations are following suit, down to 2.5 per 100,000 people. Flu B continues to be the dominant strain, accounting for 63.8% of clinical lab samples and 30.3% of public health lab samples.
Regional variations persist. The Midwest is still experiencing slightly higher rates than other regions, but is catching up as cases fall. The West currently has the lowest ED visits (0.4%) and very low wastewater activity. The South and Northeast are in between, with ED visits around 0.6%, though hospitalizations remain a bit elevated in the Northeast at 2.5 per 100,000.
RSV’s Unexpected Persistence
Unlike the easing flu situation, Respiratory Syncytial Virus (RSV) continues to circulate at surprisingly high levels for this time of year. RSV test positivity is currently at 9.1%, approaching last year’s peak of 11%. ED visits remain steady at 0.6%.
The Midwest and West are currently hotspots for RSV, with ED visits around 0.7%, while rates are slightly lower in the South (~0.6%). Infants and young children remain the most vulnerable, with ED visits particularly high for those under one year aged (5.0%) and those aged 1-4 years (4.1%). Hospitalizations are elevated at 3.0 per 100,000, with rates decreasing for infants and toddlers but remaining concerning.
Other Respiratory Viruses on the Rise
Several other respiratory viruses are also circulating widely. Human coronaviruses have peaked but remain at high levels. Human metapneumovirus is rising steeply, potentially peaking sooner than last year’s mid-April peak. Adenovirus is also experiencing a resurgence, while parainfluenza and rhinoviruses/enteroviruses remain at low levels.
Stomach Bugs Still Making the Rounds
Norovirus continues to cause outbreaks, with test positivity remaining very high at 13.7%. While there’s been a slight decrease in recent weeks, heightened levels are expected to persist for several more weeks. The Midwest is particularly affected, with test positivity at 17.1%, while rates are stagnating at high levels in the South (11.1%). The Northeast is seeing improvement, with test positivity dropping from 15.3% to 10.6%.
Emerging Threats: Measles and Avian Flu
Beyond the usual suspects, two emerging threats are demanding attention. Measles outbreaks continue to spread across the U.S., with 1,281 confirmed cases reported in 31 states so far this year. South Carolina has been particularly hard hit, with over 650 cases, followed by Utah, Florida, and Texas. CDC staff are being deployed to South Carolina to assist with outbreak response.
A case of highly pathogenic avian influenza (H5N1) has been reported in Cambodia, marking the country’s first case this year. While human cases are rare, they are closely monitored due to the potential for severe illness and the risk of the virus mutating to spread more easily between people.
Food Recall Alert
Several food recalls have been issued due to contamination. Consumers should check their cupboards and discard the following products:
- Expanded recall of frozen chicken fried rice products (Trader Joe’s, Ajinomoto, Kroger, Ling Ling, and Tai Pei) due to possible glass shards.
- Great Value Cottage Cheese (Walmart)
- Elite Treats Chicken Chips (for dogs) due to potential Salmonella contamination.
- Bremer Family Size Italian Meatballs (frozen, ready-to-eat)
- Multiple flavors of cream cheese under the Made Fresh Salads, Inc. Label
- Gerber Arrowroot biscuits
- Organic chia seeds sold by Navitas Organics
FAQ
Q: Is it too late to get a flu shot?
A: While the peak of flu season is passing, getting vaccinated now can still provide some protection, especially if you haven’t already been vaccinated.
Q: What are the symptoms of RSV?
A: RSV symptoms are similar to a common cold, including runny nose, cough, and fever. Yet, it can cause more severe illness, especially in infants and older adults.
Q: How can I protect myself from norovirus?
A: Frequent handwashing, especially after using the restroom and before preparing food, is the best way to prevent norovirus infection.
Q: Where can I find more information about measles outbreaks?
A: You can find the latest information on measles outbreaks from the CDC website.
Pro Tip: Stay informed about local outbreaks and follow public health recommendations to protect yourself and your community.
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