Flu cases on the rise amid holiday travel, gatherings, latest CDC data shows

(NEW YORK) — Flu activity is increasing across the U.S. amid holiday travel and gatherings, according to the latest data the Centers for Disease Control and Prevention.

The CDC estimates there have been at least 4.6 million illnesses, 49,000 hospitalizations and 1,900 deaths from flu this season so far, according to data updated as of Dec. 19, and experts expect these numbers will continue to rise.

Public health experts previously told ABC News that many of this season’s cases are linked to a new flu strain called subclade K — a variant of the H3N2 virus, which is itself a subtype of influenza A — that has been circulating since the summer in other countries. 

Of the 163 samples of H3N2 viruses collected since Sept. 28 and genetically characterized, 89% were subclade K, according to the CDC. 

Additionally, three pediatric flu deaths have been reported so far this season, according to an ABC News tally.

Last season, the U.S. saw 288 children die from flu, which is the same number of children who died during the 2009 H1N1 pandemic. About 90% of kids who died from flu last year were not vaccinated, a CDC study published earlier this year found.

Meanwhile, New York state is reporting the highest number of flu cases it has ever recorded in a single week. 

“The emergency room has been busy, and we’ve been following these numbers,” Dr. Darien Sutton, a board-certified emergency medical physician and ABC News medical correspondent, told “Good Morning America” on Monday. “Just a note, national numbers typically lag during the holiday, but state health department numbers are giving us insight to just how severe this flu season is.”

A total of 71,123 flu cases were reported for the week ending Dec. 20, according to the New York State Department of Health (NYSDOH). This marks the highest number of flu cases in a single week since it became mandatory for states to report in 2004. 

This is also 38% higher compared to the previous week which saw 51,365 infections reported, bringing the total flu cases reported in the state to 189,312.

Hospitalizations climbed by 63% in the most recent week, increasing from 2,251 to 3,666 weekly admissions, according to data from NYSDOH.

Sutton said it’s important to understand that flu is present and to take steps to reduce risk, including masking, washing hands with soap and water and getting the flu vaccine.

Currently, the CDC recommends that everyone aged 6 months and older, with rare exceptions, get a flu vaccine.  

The federal health agency states on its website that getting an annual flu shot prevents millions of illnesses and flu-related doctors’ visits every year and is especially important for those at higher risk of serious complications.

“The flu is so much more than a simple cold. I am treating it in the emergency room,” Sutton said. “Understand that people are coming in feeling like they are so sick that it has to be something else than the flu.”

Sutton noted that he is seeing more people in the emergency room and more people being hospitalized but that the disease itself is not more severe, adding “it’s not like a super flu.”

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