Swimming in the warm freshwaters of lakes and rivers are single-celled organisms of the species Naegleria fowleri. These amoebas are microscopic and imperceptible to the human eye. In infected waters, the amoeba swims up the person’s nose and make its home in the brain, where it starts to destroy brain tissue. Of note, you can’t get infected by swallowing water with the amoeba.
"We believe that the individual contracted the infection after swimming in unsanitary water on a single private property," said Mara Gambineri, the communications director for Florida Department of Health. She notes that this is an isolated incident that poses no risks to the general public.
Symptoms of the infection typically begin within a few days up to around a week. Often mistaken for meningitis, the symptoms include fever, nausea, vomiting. However, as more brain tissues are destroyed, the patient will suffer from seizures and hallucinations.
Unfortunately, primary amebic meningoencephalitis is usually fatal; patients usually die within 3 weeks of the diagnosis. Of the 138 cases of N. fowleri infections between 1962 and 2015, only three people have survived – a fatality rate of 97.8 percent.
But, three people did survive, and from one such case in 2013, the treatment plan has been adopted into a treatment regimen for N. fowleri infections. Known as the Hardig protocol for Kali Hardig, the 12-year-old who contracted the amoeba, doctors prescribed a combination of anti-fungal medications and an experimental drug called miltefosine (Impavido). In addition, they also induced a coma and lowered her body temperature while the drugs were taking effect.
Doctors hope the success of this case will also carry forward for the current Florida patient, who has already been promptly treated with miltefosine. "This is the most optimistic, cautiously optimistic, I've been so far as compared to other cases because of how fast [the patient was] diagnosed and how quickly treated in combination with other drugs," said Todd MacLaughlan, CEO of Profounda, the makers of miltefosine.
It is important to reiterate that cases of the brain-eating amoeba are very rare. The CDC estimates 4 to 8 cases of N. fowleri infections per year. By comparison, the CDC reports an average of 3,536 drownings annually (about 10 deaths per day). Still, even with a low risk for infections, health experts caution to prevent water entering the nose when swimming.
Additional sources: CNN news