NEW YORK (CBSNewYork) — The flu virus is rapidly spreading across the country, causing more deaths and hospitalizations.

The Centers for Disease Control and Prevention reports the flu is now widespread in 46 states, nearly four times as many compared with this time last year.

One in roughly 10,000 children under the age of four have been hospitalized with the flu this season.

Eight-month-old Kingston Smith is one of them.

“About four days ago, he started breathing hard, vomiting, having fevers,” his mother, Shareeka Smith, said. “So I drove here to the hospital and they said, ‘Yes, we need to keep him.'”

Of the more than 100 people who have died from the flu so far this season, 13 are children.

“Unfortunately, it can cause a lot of complications,” said Dr. Claire Bocchini, an infectious disease specialist at Texas Children’s Hospital. “Children can get severely sick, actually need to be in the ICU.”

Making the problem worse this season is the type of flu that’s spreading: H3N2. The strain tends to hit younger and older people harder than others.

“In years where there is H3N2, we do see far more deaths,” said Dr. Daniel Jernigan, director of the CDC’s Influenza Division.

As to why there’s been so much flu activity in the last few weeks Jernigan explains, “It’s possible that a lot of folks got together during the winter holidays and so with all those folks getting together, they’re able to transmit flu and then take it and send it onto other folks… A lot of cold air, a lot of cold this season. And so because of those things, we can see a lot of influenza that gets transmitted.”

Flu vaccines have been less effective in fighting H3N2 than other influenza flu viruses, making this particular strain more difficult to contain.

“The problem with flu is you become infectious, that means you become contagious, you can give it to somebody else 24 hours before you know that you even have it. From a public health point of view it is very difficult to contain flu,” Dr. Bettina Fries, from Stony Brook University Hospital, told WCBS 880’s Sophia Hall.

H3N2, an influenza A virus, can also spread to animals.

“A strains can infect many many different species. They can infect dogs and cats and birds and because of that, usually it is the A strains that are responsible for big outbreaks,” Fries said.

It is still too soon to say just how bad this flu season will be, but the CDC believes it could reach near epidemic levels.

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