Every summer, the media reports on someone who died after being infected with a brain-eating amoeba. These cases usually occur after a person has visited a pool, waterpark, or a tepid lake.
These horrifying infections are exceedingly rare, but they can still occur after a person comes into contact with the amoeba at home. Most recently, a woman died after inhaling a brain-eating amoeba from tap water she used in a Neti pot to irrigate her sinuses.
The 69-year-old Seattle resident was instructed by her doctor to rinse her sinuses twice daily to clear up a chronic sinus infection. So she filled a Neti pot with tap water filtered through a Brita Water Purifier and was on her way towards feeling better, or so she thought…
The unnamed woman’s real problems started when she noticed a raised, red sore on the bridge of her nose. Her doctor diagnosed it as rosacea and prescribed an ointment, but it didn’t work. So the woman spent the better part of a year seeing dermatologists in a hunt for answers.  
Then, the woman began experiencing shaking on her left side, as well as numbness in her left arm and leg, all of which were found to be the result of a seizure. A CT scan showed a lesion on the woman’s brain, so doctors biopsied the area and sent it to Johns Hopkins University for analysis, thinking it could be a tumor.  
Additional scans performed over the next several days showed the lesion was getting worse and new lesions were starting to appear. This led to a neurosurgeon at Swedish Medical Center, where the woman was being treated, opening the woman’s skull to take a closer look at the problem. He discovered that the woman’s brain was infected with an amoeba. 
The U.S. Centers for Disease Control and Prevention (CDC) rushed the anti-amoeba drug miltefosine to Seattle, but it was too little, too late. The woman lapsed into a coma and her family eventually chose to remove her from life support.  
Postmortem tests showed the woman died of Balamuthia mandrillaris, an amoeba that can reside in both soil and water. Balamuthia can travel to the brain and cause a deadly infection. Little is known about how the amoeba is contracted or how to prevent it. 
Researchers reported details of the case in the International Journal of Infectious Diseases. They warn that because Balamuthia is difficult to diagnose, “it is possible that many more cases of Balamuthia have been missed.”
About 200 cases of Balamuthia have been reported globally, with at least 70 of them reported in the U.S.
Had the woman survived, it would have been close to a medical miracle; Balamuthia has a fatality rate of 87-95%. 
Another type of brain-eating amoeba, Naegleria fowleri, killed 2 people in Louisiana after they used tap water to irrigate their sinuses with a Neti pot. Naegleria fowleri has an even more dismal fatality rate of about 98%. 
Only distilled, sterile, or cooled boiled water should be used for sinus irrigation, according to the U.S. Centers for Disease Control and Prevention (CDC). However, the Seattle woman’s doctors weren’t able to definitively link the Balamuthia infection to her Neti pot, as the water in her home wasn’t tested for the amoeba.
Even so, they hope her case will lead more doctors to suspect an amoeba infection if a patient develops a sore or rash on their nose after rinsing their sinuses. 
So, be cautious, but don’t freak out. You’re more likely to drown than inhale an amoeba.
 USA Today
 Live Science