New Flu Mutation Causes Severe Illness: See Latest NY Data

NEW YORK — Close gatherings over the Thanksgiving holiday could cause an uptick in emergency room visits in New York due to a trio of respiratory illnesses that typically rise this time of year, as well as a new mutation of the common flu that doesn’t respond to this year’s flu shot.

New York emergency rooms typically see an increase in COVID-19, influenza and RSV rates during the holidays. This year’s flu season could be more serious due to a new Influenza H3N2 mutation known as “subclade K,” which is spreading in North America, including the United States.

Although the current flu vaccine offers protection against the H3N2 strain, it doesn’t cover subclade K, which hadn’t been identified when the vaccine was developed. The variant has mutated seven times, making H3N2 an even more serious threat, according to experts.

“Knowing that there’s a new mutated strain out there and H3N2 generally causes more severe disease is concerning,” Dr. Robert Hopkins Jr., medical director of the National Foundation for Infectious Diseases, told NBC’s “Today” show.

The symptoms of the new strain are similar to those caused by common influenza, including fever, chills, body aches, headaches, extreme fatigue, congestion or runny nose, and coughing.
The symptoms come on suddenly. “It’s that hit-by-a-truck feeling,” Hopkins told “Today.”

This particular mutation is now dominant in many countries, including Japan, the United Kingdom and Canada, Forbes reported.

The CDC currently lists Influenza A H3N2 as the cause of most flu cases in the United States. The extent of the spread of the subclade K mutation in the United States is unknown because the agency didn’t do any tracking for its FluView report during the recent government shutdown.

The latest data from the CDC, last updated on Nov. 19, shows that acute respiratory illness rates overall are low in New York, but that could change in the coming weeks.

There were 2,400 influenza cases across New York as of Nov. 15, up from 1,348 from the previous week.

Nationwide, acute respiratory illnesses remain at low or very low levels, according to the CDC; however, emergency room visits for RSV are increasing in many states in the South and Southeast. COVID-19 activity remains low, and seasonal flu activity is low nationally but increasing, according to the surveillance report.

Wastewater surveillance reports from 11 monitoring sites will provide a clearer picture of COVID, flu and RSV rates in New York when the data is updated Friday.

On Sept. 25, it showed very low rates COVID across 11 sites, low rates of influenza A across 8 sites, and very low rates of RSV across 9 sites in New York.