RARE brain-eating cells killed a woman after she rinsed her nose out with tap water.

When the American OAP from Seattle underwent brain surgery earlier this year, her doctors were stunned.

Last January, she was admitted to A&E after suffering a seizure. Doctors took a CT scan of her brain to find what they first thought was a tumour.

But an examination of tissue taken from her brain during surgery a day later showed she was up against a much deadlier attack - one that was eating her alive.

Dr Charles Cobbs, a neurosurgeon who operated on the woman, said: "When I operated on this lady, a section of her brain about the size of a golf ball was bloody mush.

"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."

The woman died a month later from the rare organisms that entered her brain after being injected into her nasal cavity by way of a neti pot - a teapot-shaped product used to rinse out the sinuses.

The study was authored by Swedish doctors and researchers who worked on her case, including Cobbs. The publication doesn’t identify the victim.

The woman’s infection is the second ever reported in Seattle — the first came in 2013 — but the first fatality to be caused by it.

In 1990, researchers first became aware that this type of amoeba can cause disease in people, according to a study published in Clinical Infectious Diseases in November.

That report found there have been 109 cases of the amoeba reported in the U.S. between 1974 and 2016.

Ninety percent of those cases were fatal.