Deadly Brain Illness Linked To Flu In Children: What To Know In NJ

NEW JERSEY — As an intense influenza season continues in New Jersey, health experts are warning parents about a rare, but deadly, brain infection some children are developing after they get the flu.

Cases of acute necrotizing encephalopathy (ANE) are rising around the country after a several-year lull, said Dr. Uzma Hasan, Division Chief of Pediatric Infectious Diseases at RWJBarnabas Health. She said pediatricians have been monitoring the uptick.

"We don't really know why this is happening," she told Patch.

Hasan said she knew of one New Jersey child who developed the condition, and was transferred to the Children's Hospital of Philadelphia.

The neurologic condition is most commonly reported in young children and has a 40 to 50 percent mortality rate, she said. Symptoms "are not subtle," Hasan said, and include seizures, an altered mental state, high fever, and the child being limp or lethargic.

"This is very, very rare," she said, "But there are signs that a child is going to progress rapidly, and a parent is going to pick them up."

Dr. Michael Osterholm, director of the Center for Infectious Disease Research at the University of Minnesota, told MSNBC's Nicolle Wallace that the Centers for Disease Control and Prevention is not sharing information about ANE. Osterhom said he knows of 12 children hospitalized with the condition in Boston and another 10 at Stanford.

"This is a serious brain complication of an influenza complication," he said. "Parents should know about this."

Osterholm said symptoms can look like the flu at first, but pointed to other signs parents can look for.

“That’s how it starts — the fever, the muscle aches, the chills," he said. "But then there’s a certain lethargy, meaning (a) certain tiredness, a lack of consciousness, where it’s very hard to arouse the children. Those are the symptoms, when they appear, you need to seek medical care immediately."

"This is something we can do something about, if parents understand this is occurring now and get their children in early," Osterholm said.

New Jersey has one of the highest numbers of flu cases in the U.S., according to the Centers for Disease Control and Prevention. Hospital admissions and emergency department visits for the flu remain "elevated" across New Jersey, according to the state Department of Health's most recent Respiratory Illness Surveillance Report.

"The flu numbers are very, very significant," Hasan said.

Hasan said that flu-related hospitalizations have been rising over the past few years, as people relaxed their COVID-related precautions such as masking, social distancing, and washing their hands frequently.

"The numbers dropped significantly, and then in 2023, 2024, we started seeing an uptick in flu-related illnesses, pneumonia and things like that," she said. "And we're seeing the same this year."

Flu has also hit K-12 schools hard in the new year, with more than 100 outbreaks reported to the Department of Health in January or February. Across the state, more than 30 percent of students were home sick with the flu in the week ending Feb. 1, state data shows.

There have been 126 flu-related deaths reported to the state Health Department from September through the first week of February. The number of influenza-associated deaths has increased over the past month to about 20 flu deaths per week; there have been no pediatric deaths, per the NJDOH.

Hasan urged parents not to take the flu lightly, and said hospitals have seen children develop other flu-related complications such as bacterial pneumonia, ear infections, or the breakdown of muscle tissue. Within the RWJBarnabas pediatric system, she said more than 150 children had been hospitalized for flu-related pneumonia and other flu-related illnesses since October.

"These kids come in significantly sick," she said.

Getting a sick child in to the hospital early, and making sure the child is vaccinated against influenza, can prevent a more serious illness, she said.