Brain-Eating Amoebas Claim 4 Lives in 2015

A fatal kind of brain-eating amoeba has killed four people in 2015, most recently a 14-year-old student athlete from Texas.

Michael John Riley Jr. of Houston, Texas, who was preparing to start his ninth-grade year at Cypress Ridge High School, contracted the condition while swimming with the school's cross-country team Aug. 13 at a state park. Riley died Sunday, Aug. 30.

"Michael fought a courageous fight over the past week," said a statement from his family posted on Facebook, "allowing him to move on to be with the Lord for future heavenly tasks, a beautiful set of wings and a pair of gold running shoes."

Naegleria fowleri is an amoeba found in untreated freshwater. It can enter through the nose of swimmers, travel to the brain, and cause primary amebic meningoencephalitis (PAM). The infection is extremely rare, but 97 percent fatal. Only 133 cases of PAM have been reported since 1952, according to the U.S. Centers for Disease Control and Prevention, but several have occurred in 2015.

In addition to Michael Riley, recent victims include:

David Charar, 4, also of the Houston area, who died earlier in August 2015. His mother said that "he has left me something in my heart knowing that he enjoyed life to the fullest."

Elizabeth Marie Knight, 24, of Ardmore, Oklahoma, who died Aug. 10, 2015, after swimming in a lake with her two children, Kaitlyn and Kameron. Neither child was affected. "She was a beautiful person," her boyfriend, Eric Bowers, told KXII News 12. "Everybody gravitated to her smile and her bubbly personality. And you couldn't help but want to smile back at her and want to talk to her."

A 21-year-old resident of Bishop, California, died of PAM in June 2015, according to Inyo County Public Health officials. Her name has not been released.

Though more cases than usual have been reported this year, the risk remains so low that health officials have not warned people away from swimming in untreated freshwater such as lakes and rivers. Those wanting to take precautions can try to minimize the amount of water that enters their noses.