A 6-year-old boy from Washington state died from polio-like symptoms Sunday. The mysterious ailment caused Daniel Ramirez's brain to swell, leading to his untimely death. The child might have suffered from Acute Flaccid Myelitis, a rare condition that mostly affects children.

Daniel’s family announced his traffic death via Facebook Monday. “Daniel was an amazingly sweet little boy, who could put a smile on anyone’s face. He had a personality that made him loved by everyone who ever met him. Daniel was taken from us too soon, but his memory will live on, and he will never be forgotten,” part of the statement read.

His family described Daniel’s disease as an “unknown virus” that affected his brain and spine on his GoFundMe page. He was placed into a coma Friday and died two days later. The family still wants to raise $20,000 to give Daniel the “celebration of life he deserves, and help the family stay on their feet while they are grieving.” They have raised more than $11,000. 

The family didn’t write Acute Flaccid Myelitis was the cause of death, but the rare condition has affected 89 patients in 33 states, according to the Centers for Disease Control and Prevention. “Acute flaccid myelitis (AFM) is a condition that affects the nervous system, specifically the spinal cord, which can result from a variety of causes including viral infections. AFM is characterized by a sudden weakness in one or more arms or legs, along with loss of muscle tone and decreased or absent reflexes,” writes the CDC.

Patients suffer from pain in their arms or legs, but symptoms are rare. Sometimes people will suffer from numbness or facial weakness. The CDC is investigating what causes AFM and what puts people at risk for it.

In Daniel’s case, his family took him to Seattle Children’s Hospital Friday after he felt cold and dizzy, his parents told KOMO-FM Monday. He was paralyzed within hours and never recovered. Though doctors suspect AFM, they have not confirmed it.

Eight children were admitted to Seattle Children’s Hospital with acute neurologic illnesses, KIRO-TV wrote Tuesday. Five were released Friday. Daniel was on the only one who died.

“It’s something that’s very scary for people because it’s a polio-like illness and it can show up in otherwise healthy children,” Dr. Aaron Michael Milstone, the Associate Professor Pediatrics at John Hopkins University School of Medicine, told People Magazine last month.

Children should seek medical help if they have trouble walking or operating their arms. “If they have weakness in the leg, the child may not walk right, they may limp a little or if they have trouble holding up their arms,” he said. “That’s when they want to check in with their pediatrician.”

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