A recent report has confirmed that two people in Louisiana have died of a rare brain infection caused by an amoeba found in tap water used in a neti pot. The amoeba, Naegleria fowleri, can be found in freshwater, including tap water. The amoeba infection is rare—only 32 infections were reported from 2001 to 2010, but it can be fatal.
The infection typically occurs when people go swimming or diving in lakes and rivers, but the infection can be acquired when contaminated water from other sources enters the nose, as when the head is submerged, or with the use of a neti pot.
Use of the neti pot can be a helpful practice for people experiencing allergies, a cold, or to help stave off sinus infections, but it is very important that filtered or distilled water is used—not tap water. Also, proper cleaning of the neti pot (they can be washed in the dishwasher), and complete drying between each use is crucial.
Not to be an alarmist, as these infections are rare, but I know a lot of people use neti pots, and for good reason, so I want to help spread the word. Be sure you are using them appropriately.