TAMPA, Fla. (WFLA) — A Tampa Bay area mother has a warning for parents after her 5-year-old son ended up in the hospital. She didn’t even know her son had been infected with COVID-19 but doctors believe that is exactly what led him to the intensive care unit.

It started last month when Raven Lester says she noticed her son Jhonas was acting different. The 5-year-old was unusually tired and had a stomach ache. He then spiked a fever that wouldn’t go away.

Raven took Jhonas to the emergency department. A few days later, he was transferred to the intensive care unit.

“He couldn’t talk to me. I couldn’t hug him. He had five different IVs,” Raven Lester said. “They’ve had to do multiple tests because his heart has been mostly affected out of all the organs.”

Jhonas was diagnosed with multisystem inflammatory syndrome, or MIS-C. It’s a rare condition where different organs become inflamed including the heart, lungs, brain, skin and eyes.

MIS-C targets mostly school-aged children. It’s believed to be triggered by COVID-19.

“I don’t know when he had COVID. I don’t know how he got it,” said Raven.

Many kids that develop MIS-C never had the classic COVID-19 symptoms, partly due to their age, said Dr. Allison Messina from Johns Hopkins All Children’s Hospital.

“Sometimes it can be a very tricky diagnosis to make,” Dr. Messina explained.

The Centers for Disease Control and Prevention has tracked more than 4,600 cases since May 2020. According to the CDC, 41 children have died.

“There’s not one specific blood test that you can hang your hat on and say yes or no, so it’s really a series of blood tests looking at inflammatory markers,” Dr. Messina said.

In addition to a blood test, doctors may use a chest x-ray, heart or abdominal ultrasound to look for inflammation.

Raven’s son has since been discharged from the hospital. She’s sharing her story to warn other parents.

“This has been absolutely traumatizing for him as well as for me,” she said.

Dr. Messina says most children fully recover from MIS-C.

MIS-C was only identified last year so, for now, it’s unclear if there’s any long-term impact on the child’s health.