Details about the child, the death, or when it happened have not been released.
"The tragic death of a child due to the flu is a reminder of the devastating effects this illness can have on people of all ages," the NYC health department said in a statement. "The influenza season is far from over, and it is not too late to get the flu shot. We urge parents to protect themselves and their families by getting this potentially life-saving vaccine today."
Two other New York City children had died from the flu, including an 8-year-old girl from Queens, officials said.
Amely Baez, from the Elmhurst section of Queens, was rushed to the hospital, where she died at about 6:30 a.m. Monday.
No details have been released about the other child, other than saying it was a pediatric patient from New York City.
New Jersey and Connecticut each confirmed one pediatric flu death this season.
"This time last year, (New York City) had about four deaths, and unfortunately, not speaking to these individual cases, among children who die of the flu, usually the vaccination rates are low," Health Commissioner Dr. Mary Bassett told abc7NY. "We really want to see children vaccinated."
Flu vaccines are available at pharamcies for children as young as 2. For more information, New Yorkers can call 311, visit nyc.gov/flu or text "flu" to 877877.
Nassau and Suffolk counties are offering free flu shots this weekend. Shots are available at the Nassau County Department of Health in Hempstead, and in Suffolk County, at the Riverhead Library or at the H. Lee Dennison Building Plaza.
Nationwide, the flu has further tightened its grip on the U.S. This season is now as bad as the swine flu epidemic nine years ago.
A government report out Friday shows 1 of every 13 visits to the doctor last week was for fever, cough and other symptoms of the flu. That ties the highest level seen in the U.S. during swine flu in 2009. And it surpasses every winter flu season since 2003, when the government changed the way it measures flu.
"I wish that there were better news this week, but almost everything we're looking at is bad news," said Dr. Anne Schuchat, acting director of the Centers for Disease Control and Prevention.
Flu season usually takes off in late December and peaks around February. This season started early and was widespread in many states by December. Early last month, it hit what seemed like peak levels - but then continued to surge.
The season has been driven by a nasty type of flu that tends to put more people in the hospital and cause more deaths than other more common flu bugs. Still, its long-lasting intensity has surprised experts, who are still sorting out why it's been so bad. One possibility is that the vaccine is doing an unusually poor job; U.S. data on effectiveness is expected next week.
Some doctors say this is the worst flu season they've seen in decades. Last week, 43 states had high patient traffic for the flu, up from 42, the CDC reported. Flu remained widespread in every state except Hawaii and Oregon and hospitalizations continued to climb.
"It's beginning to feel like a marathon," said Dr. Anthony Marchetti, emergency department medical director at Upson Regional Medical Center, a 115-bed hospital in rural Georgia. A quarter of the hospital's emergency department visits are patients with flu, and the hospital has added nursing staff and placed beds in halls to accommodate the increase, he said.
"It just means we have to keep on keeping on. We're getting used to it," Marchetti said.
So far, it has not been a remarkably bad year for flu deaths. Flu and flu-related pneumonia deaths have lagged a little behind some recent bad seasons. The CDC counts flu deaths in children and there have been 63 so far. They have gone as high as about 170 in a season. Overall, there are estimated to be as many as 56,000 deaths linked to the flu during a bad year.
But reports of deaths - some in otherwise healthy children and young adults - have caused growing fear and concern, health officials acknowledge.
(The Assoicated Press contributed to this report)
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