Doctors blame tap water in neti pot for brain-eating amoeba

The 69-year-old Seattle woman had gone to her doctor for help with a nagging sinus infection and had been told to flush out her nasal cavities with water using a device sometimes called a neti pot, according to a case report in the International Journal of Infectious Diseases. She underwent surgery at Seattle's Swedish Medical Center to remove what lead neurosurgeon Charles Cobbs thought was a brain tumor, the study said. When the doctors looked at these samples of the tissue under the microscope, they could see the amoebas.

Lab results later revealed that the infection in her brain and nose rash were caused by an amoeba called Balamuthia mandrillaris, which is often associated with a disease called granulomatous amoebic encephalitis (GAE), according to the Center for Disease Control. The woman told her doctor she had used tap water in a Neti pot, instead of saline or sterile water, CBS affiliate KIRO reports. Rather than filling her neti pot with saline or sterile water, she used tap water filtered through a store-bought water filter. When doctors took a CT scan of her brain, they found what they initially believed to be a large tumour. The CDC says it's possible that the amoeba may also live in water.

You can't get the infection from drinking contaminated water or swimming in a properly chlorinated pool, and it hasn't been shown to spread through vapor from a hot shower or humidifier, according to the CDC. But unfortunately, the infection was too severe, and the woman died. She wasn't immediately aware of any other local cases of infection. Since 1993, the CDC says, there have been at least 70 cases in the United States. In this case, however, it was the neti rinse device that delivered the amoebas, via infected tap water, into her nasal passages and into her olfactory nerves, the scientists said. That aligns with what the victim experienced, as her first likely symptom was a red sore on her nose that doctors kept misdiagnosing as the common skin condition rosacea. This amoeba was not even known 20 years ago hardly.

It is thought the amoebas are primarily soil-based, but the "exact environmental niche is really unknown", Cope said in an email.

Even though such infections are very rare, there were three similar USA cases from 2008 to 2017.

"From my understanding it's everywhere. So that's what we suspect is the source of the infection", Cobbs said, according to KIRO. "It's always going to be an uphill battle because people learn by seeing things over and over again, but I don't think that there are going to be an increase in cases in the future".