'Brain-eating' amoebas kill nearly 100% of victims. Could new treatments change that?

On a hot Saturday in San Antonio over 10 years ago, an 8-year-old boy was rushed to the hospital after days of fever, headache, vomiting and sensitivity to light. The child's mother, who lived near the Texas-Mexico border, had taken him to a series of clinics in Mexico, but his condition had worsened. The child was now unconscious and unresponsive to sound, light or other stimuli. 

Doctors put the child on a ventilator and began a breakneck effort to find out what was wrong. What they discovered, swimming in the boy's cerebrospinal fluid, was an organism that left little room for hope: Naegleria fowleri, more popularly known as a "brain-eating amoeba." 

It was the third case that Dr. Dennis Conrad, a pediatric infectious disease specialist, then at University Hospital in San Antonio, had ever seen in his career. The other two patients had died.

But Conrad had recently read that a new drug option, miltefosine, had been approved as an experimental treatment for N. fowleri infections. He added it to the boy's drug regimen, which already included other antimicrobial and anti-iNFLaMMAtory medications. 

"It's the kitchen sink," Conrad told Live Science. "It's a bad disease, and you just hit them with everything you can think of." 

The child's prognosis was grim. He had been sick for five days before arriving in San Antonio, and most people who contract an infection with N. fowleri die about five days after symptoms start. According to the Centers for Disease Control and Prevention (CDC), there were 157 confirmed human cases of N. fowleri infection in the United States between 1962 and 2022. Four survived.

Elsewhere in the world, the numbers are similar. It's rare to become ill from an infection with this amoeba — and it's very, very rare to survive. But the few recent survivors may owe their recovery to miltefosine, the most recently recommended new medication for primary amebic meningoencephalitis (PAM), the disease caused by the amoeba. New drugs may be on the horizon as well. The question is whether they can reach patients before the damage is done.