— A memorial service was held Wednesday in Arlington for the seven-year-old son of a former San Marcos resident.

Kyle Gracin Lewis died Aug. 29 of Naegleria fowleri, a freshwater parasitic amoeba he apparently became infected with while on a family vacation in Erath County.

He was the son of Jeremy Lewis and Julie Mayfield Lewis, who was born and raised in San Marcos.

The family had a tradition of taking a vacation just before the start of the school year, said Sally Medford, his great-aunt.

Medford said she had followed the family vacation through Facebook postings. “It was a week of swimming and fishing and the whole family was there.”

She said Kyle was feeling fine as the family came home and he started second grade. But the next day, after baseball practice, “he felt a little sick.”

The boy woke the next day with a headache and was soon vomiting.

Initially, doctors suspected meningitis and performed a battery of tests including spinal taps, Medford said, but didn’t realize the true source of the sickness until it was too late.

“It was only about 4:30 Sunday morning when they figured out what it was. He died at 5:30.”

According to the Centers for Disease Control, Naegleria fowleri is found in warm freshwater as well as soil.  It enters the body through the nose, typically as victims swim or dive. The parasite makes its way to the spinal cord and brain, causing a brain infection the CDC says is most often fatal.

The parasite cannot survive in fast-moving streams like the San Marcos River, but can exist in warm stagnant areas and pools.

The Web site nbcdw.com reported the boy had been swimming in the Paulaxy River in Dinosaur Valley State Park near Glen Rose.

The disease is rare, with the CDC reporting 33 infections between 1998 and 2007. Most of the infections occur during July, August and September. “They usually occur when it is hot for prolonged periods causing higher water temperatures and lower water levels,” the CDC says. “Infections can increase during heat wave years.”

“He was exceptional, such a delight, so active and bright,” Medford said. “It’s shocking that he’s not here.”

The boy’s entire baseball team, coached by his father, was expected to attend the memorial service. Medford said they are dedicating their season to Kyle.

For more from the CDC on preventing recreational water illnesses, visit www.cdc.gov/healthyswimming.