Flu cases surge nationwide as experts warn of rising hospitalizations

Health experts are raising alarms as flu activity surges across the United States, with most states now reporting high or very high levels of illness.

(CNN)- Health experts are raising alarms as flu activity surges across the United States, with most states now reporting high or very high levels of illness.

“What we’re seeing right now is a very rapid escalation in cases,” said Dr. Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.

According to the Centers for Disease Control and Prevention, at least 7.5 million flu illnesses have been reported so far this season, based on data through December 20. Hospitalizations, emergency room visits, and even flu-related deaths are all on the rise.

“We’re seeing a major increase in hospitalizations, emergency department visits, and even deaths,” Osterholm said.

Health experts say several factors are driving the surge. One major issue is lower vaccination rates.

“There have been about three million fewer doses given this year so far,” said Dr. Debra Houry, former chief medical officer at the CDC.

Another concern is the dominant strain circulating this season. According to experts, a strain known as H3N2 is contributing to more severe illness.

“Flu is always made up of several different types of viruses,” said Dr. Ashish Jha, former dean of the Brown University School of Public Health. “We have one this year that is a bit unusual. It’s called H3N2, and it’s associated with more severe illness and more infections.”

Genetic testing has also identified a new flu variant, known as subclade K, which appears to be responsible for the majority of cases in the U.S.

“It’s a different subclade, or kind of a different strain,” Houry explained.

Health officials say the new variant was identified after this year’s flu vaccines were finalized, meaning it was not included in the current shot. Still, experts stress that vaccination remains important.

“It’s probably not going to do a great job of protecting you against infection from the new variant,” Jha said, “but it will do a good job of preventing you from getting seriously ill.”

Health officials continue to encourage vaccination, good hygiene, and staying home when sick as flu activity remains elevated nationwide.