The Centers for Disease Control and Prevention (CDC) is cautioning people to never use tap water with a neti pot as it can contain dangerous bacteria. The warning comes after a 69-year-old woman contracted a fatal brain-eating infection after rinsing her sinuses with unfiltered water.
According to a report published in the International Journal of Infectious Diseases, the Seattle woman first started experiencing rash-like symptoms. Doctors were unable to diagnose the issue until a year later when she had a seizure and was rushed to Swedish Medical Center, where they realized it was a parasite known as Balamuthia mandrillaris.
“There were these amoeba[e] all over the place just eating brain cells. We didn’t have any clue what was going on, but when we got the actual tissue we could see it was the amoeba,” neurosurgeon Dr. Charles Cobbs told the Seattle Times. By that time, it was too late for treatment, and the woman died a month later.
“Due to the difficulty of diagnosis and severity of this infection, the fatality rate for Balamuthia infection is near 100 percent,” wrote the report’s authors, explaining that the parasite is often missed. In this specific case, they believe the infection was caused by the use of unfiltered water in the neti pot.
As a result, doctors from the CDC are urging people to make sure they use neti pots correctly, with only distilled water. Tap water can contain certain bacteria that are safe to swallow (because they’re killed by stomach acid) but become fatal if they enter the nasal cavity and travel to the brain.
While the Balamuthia infection is very rare (there have been only three similar cases in the U.S. over the last 10 years), some experts, like Dr. Cynthia Maree at the Swedish Medical Center, think that could become more common. “I think we are going to see a lot more infections that we see south (move) north, as we have a warming of our environment,” she said.