Trio Of Illnesses, New Flu Mutation Concerns Experts: What To Know In IL

Close gatherings over the Thanksgiving holiday could cause an uptick in emergency room visits in Illinois 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, health officials said.

Illinois 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. As of Nov. 15, 0.3 percent of emergency room visits in Illinois were related to COVID-19, while 0.4 percent had to do with influenza.

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 because the Centers for Disease Control and Prevention 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 very low in Illinois.

Comparing the week of Nov. 15 to the week of Nov. 8, Illinois hospital admissions for COVID-19 dropped by 0.11 percent, but they rose by 0.06 percent for the flu, according to state data. Emergency room visits related to acute respiratory illnesses dropped to 9.5 percent from 11.7 percent, respectively.

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 56 monitoring sites will provide a clearer picture of COVID, flu and RSV rates in Illinois when the data is updated Friday. On Nov. 20, it showed Illinois activity levels to be "very low" for COVID-19, influenza and RSV.