I like introducing you periodically to some of the stranger and more dangerous germs out there. It’s a good reminder that nature isn’t just full of daisies and rainbows, and that the most lethal dangers we face are natural.

This week’s news presents a terrific example. Meet Naegleria fowleri. Naegleria fowleri is an amoeba, a single celled parasite that lives in warm bodies of fresh water, like lakes and rivers. Its nickname is the brain-eating amoeba. Isn’t that nice? (My nickname is Al.)

Before we find out why Naegleria (neg-LE-ria) is in the news, let’s get some background.

Infection with Naegleria is very rare. There have been 32 reported cases in the U.S. in the last ten years. Drinking water contaminated with Naegleria is perfectly safe, as Naegleria does not cause infection when swallowed. Naegleria only causes infection when contaminated water goes into the nose. Most cases have occurred in people swimming in fresh water lakes and rivers, frequently in southern states and usually in warmer weather. Some cases have also occurred in swimming pools that were not chlorinated.

When infection occurs, the amoeba crosses from the nasal sinuses into the brain and causes a disease called primary amebic meningoencephelitis (PAM) in which brain tissue becomes inflamed and is destroyed. As any neurologist or fan of zombie movies will confirm, destroyed brain tissue is bad. PAM is almost always fatal. It’s a good thing it’s so rare.

This week, a new mechanism for acquiring Naegleria infection came to medical attention. A woman in Louisiana became the second in the state to die this year from Naegleria that was likely acquired through the use of a neti pot. A neti pot is a small container shaped like a genie’s lamp that is used to flush water up the nose to clear nasal congestion. Many people with nasal allergies or colds prefer irrigating their noses and sinuses rather than taking decongestants. This is an important reminder that nasal irrigation should always be done with sterilized water – water that has been boiled or filtered. Unsterilized tap water is not safe for nasal irrigation. Remember, Naegleria in drinking water is perfectly safe, unless it’s flushed up the nose.

The Louisiana Department of Health published a press release warning of the potential danger of using neti pots with unsterilized water. The alert reminds us that neti pots or other nasal irrigation systems should be washed between uses and allowed to air dry. This effectively kills any amoeba in the equipment.

So if you are going to flush water up your nose, either buy sterile saline from your drug store, or boil some tap water first.

Finally, should we worry about swimming in lakes or rivers? Perhaps, but not because of Naegleria. Of the tens of thousands who swam in bodies of fresh water in the last decade in the U.S. only 32 developed Naegleria infection. During the same time period, there were over thirty thousand deaths due to drowning.

Learn more:

Neti pot danger? Two die from amoeba infection (Booster Shots, LA Times Health Blog)
Second Neti-Pot Death From Amoeba Prompts Tap-Water Warning (Shots, NPR Health Blog)
North Louisiana Woman Dies from Rare Ameba Infection (State of Louisiana Department of Health & Hospitals)
Naegleria, Frequently Asked Questions (Centers for Disease Control and Prevention, Parasites)

Tangential Miscellany

Lighting the darkness is a major theme of Hannukah. The holiday falls close to the winter solstice, when nights are the longest, and it always includes the night of a new moon, when the night is darkest. Increasing numbers of candles are lit every night and the menorah (candelabra) is placed by a window to be visible from the outside. It is a conscious rebellion against the cards dealt to us by nature. As the world gets darker, we illuminate our small corner of it and push back the night.

I hope in the last year my posts have illuminated a few dark topics for you. Thank you for reading. To everyone celebrating, Merry Christmas and Happy Hannukah!