Back in December, authorities learned that Naegleria fowleri — a deadly, brain-eating amoeba, was living in Louisiana tapwater, infecting its victims' grey matter by way of neti pot (http://abcnews.go.com/Health/Wellness/fatal-infections-linked-neti-pots/story?id=15170230)
The amoeba makes its way to the brain via the olfactory nerves, which it accesses when water is forced up the nose. Anything you do to reduce the risk of water being forced up your nose, probably reduces the risk of infection. If you do go in the water, don't submerge your head, or — if you do — to hold your nose, or wear a nose clip.
source : http://io9.com/5935019/minnesota-children-are-dying-from-brain+eating-amoebas
