Brain-Eating Amoeba Kills Seattle Woman Who Used Tap Water in Her Neti Pot

If you use a neti pot to clear out your sinuses, there's one important rule you should always follow: Don't fill it with tap water. Doing so could land you a sinus infection, or worse, a potentially fatal disease caused by a brain-eating amoeba. Although the latter scenario is exceptionally rare, a 69-year-old woman in Seattle died from doing just that, The Seattle Times reports. Experts are also warning that these infections could become more common as temperatures in the northern hemisphere continue to rise.

Physicians at Seattle's Swedish Medical Center initially thought the woman had a brain tumor. She was brought into the emergency room following a seizure, and a CT scan of her brain seemed to reveal a tumor-like mass. The only other known symptom she had was a red sore on her nose, which was previously misdiagnosed as rosacea. When surgeons operated on her the following day, they noticed that "a section of her brain about the size of a golf ball was bloody mush," neurosurgeon Dr. Charles Cobbs told The Seattle Times. "There were these amoeba 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."

She died a month later of an infection called granulomatous amoebic encephalitis (GAE), according to a recent case report published in the International Journal of Infectious Diseases. The disease is caused by a single-celled amoeba called Balamuthia mandrillaris, and it's extremely deadly. Of the 109 cases between 1974 and 2016, 90 percent were fatal.

According to the FDA, some bacteria and amoebae in tap water are safe to swallow because acid in the stomach kills them. However, when they enter the nasal cavity, they can stay alive for long periods of time and travel up to the brain, where they start eating their way through tissue and cells. Another brain-eating amoeba called Naegleria fowleri can cause a similar disease, except it acts faster and can cause death in just a few days. Although it's also rare, it's usually found in warm freshwater, and infections start by getting contaminated water up one's nose while swimming or by using a nose irrigation device filled with tap water.

Dr. Cynthia Maree, an infectious disease doctor at the Swedish Medical Center, said the changing environment could facilitate the spread of these infections. "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," Maree says. Researchers say these amoebae are still little-understood. Future studies would need to be conducted to learn more about the risk factors involved.