(JEWSISH VOICE NEWS)  New York is seeing the highest number of flu hospitalizations recorded in a single week, state health officials said Friday.

During the week ending Dec. 27, 4,546 people were hospitalized with influenza, a 24% increase from the 3,666 admissions reported the previous week, according to the New York State Department of Health (NYSDOH).

The surge follows a record-breaking week of flu infections in the state, with 72,133 new cases reported during the week ending Dec. 20, ABC News reported.

Last month, NYSDOH declared influenza “prevalent” in New York, requiring health care facilities and agencies to ensure staff who have not received this year’s flu vaccine wear masks in patient- and resident-facing areas.

“We are having a more severe flu season than prior years,” said Dr. James McDonald, New York’s health commissioner. “Almost 1,000 more people were admitted to a hospital during this most recent seven-day period compared to the prior week.”

Flu activity is also rising nationwide. The Centers for Disease Control and Prevention estimates at least 7.5 million illnesses, 81,000 hospitalizations, and 3,100 deaths from influenza have occurred so far this season. New York is one of 20 states reporting “very high” levels of respiratory illness, according to CDC data.

Health experts told ABC News that many of this season’s infections are driven by a new strain called subclade K, a variant of the H3N2 virus. Subclade K has been circulating internationally since summer and contributed to recent spikes in Canada, Japan, and the U.K. Among 1,600 flu samples tested by the CDC, roughly 92% were H3N2, and nearly 90% of those belonged to subclade K.

Experts expect flu cases to continue climbing in the coming weeks as cold weather persists and holiday gatherings increase. The CDC recommends that everyone six months and older, with few exceptions, receive a flu vaccine annually. The agency notes that vaccination prevents millions of illnesses and flu-related medical visits each year and is particularly important for individuals at higher risk of severe complications.