Neti pot brain-amoeba deaths are like shark week: an incredibly rare event that commands outsize attention due to reactionary schadenfreude and the sheer horror of the victim's demise. Fox News:
When a 69-year old Seattle woman had a seizure earlier this year, doctors at Swedish Medical Center thought she may have had a brain tumor. However during surgery, they discovered it was something much more unusual. … Dr. Cobb says she most likely became infected by the amoeba after treating a common sinus problem with tap water.
"We believe that she was using a device to irrigate her sinuses that some people use called a neti pot. It's extremely important to use sterile saline or sterile water. I think she was using water that had been through a water filter and had been doing that for about a year previously," Dr. Cobb said.
The FDA isn't quite so stern, saying you can use tapwater to irrigate your sinuses if you boil it for at least 3 minutes and, of course, let it cool first. The CDC says you can use filtered tapwater, but only if you're using filters that are explicitly designed to remove germs. Most fridge and store-bought filters do not remove germs.
My local water department handed out this fancy Zerowater model to householders during a local water quality scare here and I can recommend it, though it's slow to filter and the replacement filters are pricey. It also removes dissolved minerals, unlike most store brands, resulting in all the pros and cons of drinking soft water.