Zachary Reyna, the Florida boy left brain dead by a water-borne parasite, was removed from life support Monday night, according to a Facebook post by his family.

"Zac donated all his organs to others that were waiting on a miracle," reads the post on the Facebook page " Pray4Number4." "Through donating his organs, Zac is living on. His heart will be pumping for someone, his lungs will be taking breaths for someone and all his other organs will change the lives of many."

Read more about Zachary's battle.

Zachary, a 12-year baseball fan from LaBelle, Fla., was diagnosed with primary amoebic meningoencephalitis, a rare and almost-always-fatal form of meningitis caused by the amoeba Naegleria fowleri. He's thought to have contracted the brain-eating amoeba three weeks ago while knee-boarding in a water-filled ditch near his family's home.

"His strong spirit will always be among us," the Reyna family wrote, noting that Zachary's "journey to save lives" began at 10:13 p.m. Monday. "He changed all of our lives, brought us closer to God, strengthened our family and his story has touched people around the world."

Only two people in North America are known to have survived a Naegleria infection, according to the U.S. Centers for Disease Control and Prevention. A 12-year-old girl from Arkansas, Kali Hardig, is set to be the third survivor after showing signs of recovery last week.

Read about Kali Hardig's first words after contracting Naegleria.

Naegleria fowleri thrives in warm, standing freshwater and the sediment of rivers and lakes. And while it's usually harmless, it can cause fatal brain swelling if inhaled through the nose.

"This is a very rare occurrence," county health department spokeswoman Brenda Barnes told ABCNews.com when Zachary's diagnosis was confirmed two weeks ago. "This amoeba is out there. It could be anywhere in any warm, fresh water."

Early symptoms of a Naegleria infection include a severe frontal headache, fever, nausea and vomiting, according to the CDC. But those can swiftly give way to a stiff neck, seizures, confusion and hallucinations as the amoeba makes its way up through the nasal cavity into the brain.

"After the start of symptoms, the disease progresses rapidly and usually causes death within about five days," the CDC's website reads. "People should seek medical care immediately whenever they develop a sudden onset of fever, headache, stiff neck and vomiting, particularly if they have been in warm freshwater recently."

Zachary's family initially thought the boy had a virus, according to his brother, Brandon Villarreal.

Warm Weather Stirs Up Amoeba Warning

Zachary was declared brain dead Saturday, but was kept alive by a ventilator until Monday so that his organs could be donated. Family and friends were invited to visit him at Miami Children's Hospital Sunday.

"We thank you all for your support and prayers," the family wrote, noting that funeral arrangements have yet to be made. "We will post information at a later time. God Bless you all."

Zachary Reyna died Monday after battling a brain-eating parasite. (Image credit: ABC News)