As someone who regularly uses nasal irrigation — but, of course, only with bottled or distilled water — I read the most recent CDC Morbidity and Mortality Weekly Report (MMWR) with extreme interest. The MMWR's latest "Notes from the Field," dated May 29, 2025, describes the fatal case of a healthy 71-year-old woman who died in Texas last year from primary amoebic meningoencephalitis (PAM), a rare but often fatal brain infection caused by Naegleria fowleri. While most people who suffer from PAM encounter N. fowleri through recreational activities, such as swimming, in bodies of water containing the amoeba, the CDC report revealed that in this case, contaminated RV water was the source of the brain-eating amoeba.
The CDC reports that the patient had performed nasal irrigation a few times using unaltered, unboiled tap water from an RV's water faucet at a Texas campground. Four days later, she developed "severe neurologic symptoms" which included a fever, headache, and "altered mental status." She was treated for a suspected PAM infection but developed seizures and died a little over a week after her symptoms began. Post-mortem lab tests revealed that her cerebrospinal fluid contained N. fowleri.
Investigators tested a dozen water and surface samples — including from the RV water tank and the campsite municipal water supply — for the presence of N. fowleri, but didn't find it in any of the samples. This could be partly due to the fact that sampling occurred a full 23 days after the last nasal irrigation event. However, investigators did discover that the RV's water supply wasn't sufficiently disinfected, and concluded that:
Nasal irrigation using tap water remains the suspected route of exposure, given the absence of other identified nasal water exposure and the concerning quality of the campground municipal water and RV tap water at the time of sampling.
Sadly, this tragic case highlights, as the CDC states:
The potential for serious health risks associated with improper use of nasal irrigation devices, as well as the importance of maintaining RV water quality and ensuring that municipal water systems adhere to regulatory standards.
This awful case is definitely a great reminder to always use proper water when I do my nasal rinses. I'm begging you, too: If you're going to do any kind of nasal irrigation, please use only distilled or sterile water.
And as a final note, this CDC factsheet provides the useful additional information that you cannot get an N. fowleriinfection or PAM from drinking contaminated water — to get infected, the contaminated water must go up your nose.
Previously:
• How does a brain-eating amoeba eat brains?
• California woman killed by brain-eating amoeba
• 6 die from brain-eating amoeba in lakes
• 'Brain-eating' amoebas kill woman who used filtered tap water in neti pot
